Kwartaalblad van die Suid Afrikaanse Pekan Produsente Assosiasie · Quarterly Journal of the South African Pecan Producer's Association

LENTE 2015 Volume 72

Pecan Orchard

Establishment

Nuwe Seisoen

Bring

Nuwe Hoop

Save the Date:

SAPPA AGM

6&7 November 2015

Pongola

A Pe an

South African Pecan Nut Producers Association NPCSuid-Afrikaanse Pekanneutprodusente Assosiasie NPC

SA Pecans wil graag al hulle produsente bedank vir hul lojale

ondersteuning deur die jaar!!

PECAN PRO NURSERYH.W. Meier | heiko@meier.co.za

Beste Sappa lede,

Hierdie maand klim ons 'n entjie verder op die leer na die einde van 2015 : dis

Oktobermaand! Die winter is verby, die lente het gekom en ons staan met ons voete

midde-in die somer.

Vanuit die kantoor wil ons graag u aandag vestig op 'n paar veranderinge.

Met al die nuwe verwikkelinge in die pekanbedryf is SAPPA vanaf Junie 2015 as

maatskappy geregistreer. SAPPA se bankbesonderhede het dus ook nou verander.

In die vervolg kan u enige betalings in hierdie bankrekening deponeer:

Bank: First National Bank

Rek Naam: SAPPA

Rek Nr: 6254 3021 133

Takkode: 200110

BTW nommer: 4060270263

SAPPA in samewerking met Hortgro is al geruime tyd besig om die

ledelys/databasis op datum te kry. Baie dankie aan almal wat reeds hul

inligtingvorms vir ons deurgestuur het. Vorentoe sal ons weer eposse uitstuur

sodat diegene wat nog nie hul inligting kon deurgee weereens die geleentheid sal

kry.

Verder word daar ook hard agter die skerms gewerk om reëlings te tref vir die

jaarlikse Algemene Jaarvergadering wat op Vrydag, 6 & 7 November 2015 te Pongola

Country Lodge in Pongola gehou sal word. Hou hierdie datum oop, want ons wil julle

graag almal daar sien. Dit beloof om weereens interessant en leersaam te wees.

Hou u elektroniese posbus dop vir meer inligting binnekort.

Verder verwelkom ons graag ons nuwe lede wat die afgelope maande aangesluit

het. Mag julle gou deel voel van die pekanneutfamilie.

Graag wens ons Albert en Mandie Bouwmeester baie geluk met die geboorte van hul

dogter Leanél. Mag sy julle nog baie vreugde skenk.

Teen hierdie tyd is oestyd al vergete, en lê die snoei of planttyd voor. Mag die nuwe

seisoen groot uitdagings meebring.

Gegroet tot die volgende uitgawe

Harriët

“Elke dag word 86 499 sekondes aan ons geskenk

met die wonderlikste moontlikhede!!”

Office hours · Kantoor ure : Mo-Fr · | 08h30 - 13h00

Address · Adres PO BOX 32140 Totiusdal 0134 | Tel 012 329 9868

Fax · Faks 012 329 9869 · 086 244 5956 | Cell · Sel 084 403 9116

Email · E-pos admin@sappamail.net | Web www.sappa.za.org

Bank: SAPPA. FNB. Tak 200110. Rek.Nr. 6254 3021 133. BTW Nr. 4060270263

SA Pekan Redaksie: Albert Bouwmeester, Harriët Hofsink, Ronél de Jong

Ma-Vr

Uit die KANTOOR From the OFFICE

3

P R ATU

S E DM vir

2 u

aw

SOMER 016 itge

2 22.01. 016

IN THIS ISSUE

1. SA Pecans

2. Pecan Pro Nursery

3. Uit die kantoor

SAPPA office · SAPPV kantoor

4. Voorsittersverslag

5. Pieterse Pecan Industry

6. Nuwe seisoen bring nuwe hoop

7. Hedging - powerful tool for crop load

management

8. Plasing en koste van Advertensies

9. Ken jou vriendelike vyand

12. GWK

13. Pecan soil and production potential

14. Pecan orchard establishment

15. Nutmech

16. Burkea

WNG Boerdery

19. Netafim

20. Monchiero

22. Rovic Leers

23. Sappa AGM

24. Soil zinc applications in the west

can work

25. Elandsdraai Pecan Growers

Nutmech

26. Inspection Masters

27. Has rain washed away the

pecan crop?

29. Bouwer Pecan Farms and Nursery

30. Streek 7 vergaderings 2015

32. Monchiero

33. List of members of the National

Council of Representatives of SAPPA

Enviro Chainsaws

34. Don’t underestimate value of airflow,

elevation in scab control

35. Nukor

36. Meganiese boomsnoei

37. How much fertilizer do young pecan

trees need?

38. Wild Rush Distributors

39. Nutmech

40. Recipe:

Sticky-bun pumpkin muffins

Felicia Farm

Ons het 'n baie ontstuimige seisoen agter die blad. Die

meeste produksie gebiede se oes op volwasse bome was af. Die

krisis in Griekeland en Portugal het geldmarkte en aandelebeurse

laat skommel. Markte in Sjina en Europa was onvoorspelbaar en

die Rand het drasties verswak teen die US$ en die ander

vernaamste geldeenhede. Invoertariewe op pekans na Sjina is

verminder van 24% na 10%. Enkele verwerkers in Sjina wat

invoerbelasting of BTW ontduik het is in klopjagte aangekeer en

vervolg.

Hoe is die pekan bedryf in Suid-Afrika beïnvloed en hoe

het die markkragte daarop gereageer?

- Aan die begin van die seisoen was kopers in Sjina traag om

kontrakte te teken.

- Aankopers in Suid-Afrika was stadig en onseker om pryse

bekend te stel.

- Kommoditeitsfinansiering was onder druk weens die

finansiële krisis in Europa.

- Wat die pekanprys betref, het die laer as verwagte oes en die

verswakking in die Rand in ons guns getel.

- Aan die einde van die seisoen was pekanpryse in Rand terme

die beste nog ooit.

- Produserende pekanplase, veral in Vaalharts, is verkoop vir

nuwe rekord pryse.

- Bestaande produsente brei uit en nuwe beleggers tree toe

tot die pekanbedryf.

- Nuwe verwerkers en uitvoerders tree toe tot die bedryf.

Hoe lyk die toekoms vir die pekan bedryf in Suid-Afrika?

- Suid-Afrika bly steeds 'n land met groot uitbreidings-

potensiaal vir nuwe aanplantings. Ons het boere met die

regte kennis en die vermoë om te produseer; ons het die

regte klimaat; relatief goedkoop besproeiingsgrond en

voldoende goeie kwaliteit besproeiingswater.

- In die Westelike streke is vervanging met pekanneute 'n

oplossing vir besproeiingsgewasse met krimpende

winsmarges. Wyndruiwe, droogdruiwe, lusern en die meeste

kontantgewasse se winsmarges het sodanig gekrimp dat

tradisionele plaas- of perseelgrootes nie meer 'n ekonomiese

eenhede uitmaak nie. In die regte klimaat, bly 'n tipiese

eenheid van 18ha – 25ha steeds 'n baie goeie ekonomiese

eenheid, as pekanneute eers in produksie is.

- Die verswakking in die Rand bevoordeel ons direk om op

wêreldvlak mededingend te bly.

- Ons neutkwaliteit is uitstekend en bly gesog in Sjina. Om 'n

premie prys in die Sjinesemark te behou moet ons sorg dat

ons produk aan die nodige uitvoerstandaarde voldoen.

Fitosanitêre vereistes in die Sjinesemark sal verhoog soos

wat die mark meer volwassenheid bereik.

- Markontwikkeling in Sjina sowel as ander lande bly belangrik

om groeiende volumes te akkomodeer.

- Suid-Afrikaanse boere is gelukkig dat daar voldoende

kompetisie tussen aankopers bestaan. Uitvoer en

verwerking is 'n volume “game”en soos ons produksie

toeneem sal meer en meer uitvoerders ekonomies kan

uitvoer en steeds goeie pryse kan betaal.

- Grondhervorming bly Suid-Afrikaanse boere se grootste

uitdaging. SAPPA is betrokke by verskeie bemagtigings

projekte. Dit is krities dat die regte mentor en die regte

begunstigde geïdentifiseer word om sulke projekte 'n sukses

te maak.

Daar word ontsettend baie gedoen waarvan produsent

nie altyd bewus is nie: Hortgro, SAPPA se werknemers, SAPPA se

bestuurslede, die verskillende weksgroepe en kommitees, lede

wat boeredae en streeksvergaderings aanbied, lede wat

betrokke is by konferensies, simposiums en jaarvergaderings,

navorsers en universiteite, gassprekers, adverteerders, borge en

diensverskaffers, mentors by bemagtigingsprojekte, lede wat

betrokke is en boere wat medeboere met raad ondersteun.

Almal wat by SAPPA betrokke is, 'n hartlik dank vir julle

insette. Laat dit 'n skitterende jaar wees.<

Voorsittersgroete

Heiko Meier

VOORSITTERSVerslag

4

Algemene JaarvergaderingAnnual General Meeting

6 & 7 Nov. 2015@ Pongola

Met die oestyd wat agter die rug is begin die

opgewondenheid oor die nuwe seisoen wat voorlê. In my vorige

artikel het ek kortliks uitgebrei oor van die goeie insekte wat ons

in die pekanneut boorde waarneem. Daar sal 'n die volgende paar

uitgawes van ons tydskrif 'n reeks artikels verskyn geskryf deur

Dr Justin Hatting van die LNR op Bethlehem getiteld; Ken jou

vriendelike vyand. Hiermee wil ons graag ons boere attend maak

daarop dat nie alle insekte wat in die boord voorkom skadelik is

nie !

As enige boer snaakse of onbekende insekte opmerk in

sy boord kan julle my gerus kontak sodat ons 'n beter prentjie kan

skets van watter insekte in ons boorde voorkom en moontlik

skade aanrig.

Met die ongewoon warm winter wat oor groot dele van

die pekanneut produksie gebiede voorgekom het die jaar mag dit

wees dat ons ongewone insekpatrone waarneem. Bv. plantluise

wat vroeër as normaal in die boorde opgemerk word. Deur die

afgelope seisoen is plantluise oor groot gebiede in die boorde

opgemerk vanaf Februarie tot einde April. Identifikasie van die

geel plantluise het teruggekom as die Geel Pekan Plantluis. ( Sien

foto onder). Let ook op die enkel eier op 'n klein steeltjie van die

Lacewing wat saam met die luise voorkom.

\

Ek was ook betrokke by 'n paar snoei dae wat deur

groepe boere gereël is. Die een op die plaas van Mev Alta du

Preez waar gefokus is op die snoei van jong bome en op die plaas

van Mnr Hendrik Geldenhuys waar ons na die snoei van groter

bome ook gekyk het.

Ons het ook 'n boeredag op Groblershoop bygewoon

waar ons die Vrydag middag 'n praktiese sessie in die boorde

deurgebring het. Die plant van bome, snoei van jong bome en

oespraktyke het aandag gekry. Onder is die boere besig om na 'n

demonstrasie van 'n "blower" te kyk.

As deel van die UFS se navorsingsprojek is daar 15 bat

boxes op plase aangebring. Meer as een bat box ontwerp is

gebruik en verskillende paal hoogtes. 'n Paar riglyne vir enige

iemand wat belangstel om bat boxes op hul eie plaas aan te bring:

- Die opening van die box moet in 'n westilike rigting wys sodat dit

goeie laat middag son kry sou dit een van die ontwerpe wees wat

in die veld aangebring word.

- Die onderkant van die bat box moet minstens 2,5 m bo die grond

wees, maar 3m tot 3,5 m is selfs nog beter.

- Rooi perdebytjies bly ook baie lekker in hierdie bat boxes en

moet gereeld verwyder word. Verkieslik met die hand en nie met

gif nie omdat vlermuise baie sensitief is vir gif en skerp reuke.

- Wees geduldig!! Dit het 3 en 14 maande geneem voordat die bat

boxes wat ons aangebring het die gewenste inwoners gekry het.

Die projek gaan steeds voort en verdere terugvoer sal

volg. Volledige terugvoer oor die LNR en UFS navorsings-

projekte sal weer tydens die SAPPA AGM later vanjaar geskied.

Moet die geleentheid nie misloop nie! Sterkte aan alle pekanneut

produsente vir die nuwe seisoen!<

Vriendelike groete uit Hartswater

Hardus du Toit

Tegniese beampte

SAPPA

Sel: 083 465 6522

Epos: sappahardus@gmail.com

Nuwe SEISOENBring Nuwe HOOP

6

“Dis nie geluk wat ons

dankbaar maak nie, maar

dankbaarheid wat ons

gelukkig maak”

By Bill Goff and Richard HeeremaGoff is Nunn-Bond Professor and Extension Pecan Specialist-Emeritus at

Auburn University, and a pecan grower in Leesburg, Georgia. Heerema is

Extension Pecan Specialist at New Mexico State University.

Pecan South, Volume 48, No.2, April 2015

There is a line in the old Roger Miller country song "One

Dying and a Buryin"' where he says "It's so simple I'm surprised I

hadn't done thought of it before yet". That's the line that comes

to us as we have studied information on the response of pecan

trees to hedging. The simple part is that we should think of

hedging in terms of crop load management and reduction of

alternate bearing, equally so or even more than we think of

hedging as a way to reduce overcrowding and allow sunlight into

the orchard. Done correctly and, most importantly, at the right

time and to the right degree, hedging can result in consistent

satisfactory yields of high quality nuts with minimal alternate

bearing.

Only a few actual replicated experiments on pecan tree

hedging have been conducted. This is understandable as the

hedging equipment is very expensive, and the number of trees

and the effort required to do a meaningful study is very high and

limiting too many researchers. Fortunately, despite the difficulty,

several studies have now been conducted and, along with

grower experience, are telling us how the trees respond. One

long-term trial was conducted by Richard Heerema and Brad

Lewis in the Mesilla Valley of New Mexico near Las Cruces.

The study has been in place 9 years with the intended

duration 10 years, making it the longest- duration replicated

hedging study that has been done.

There were 4 treatments, implemented following an initial

hedging of all trees in the first year:

1. Hedged every year

2. Hedged every other year

3. Hedged every third year

4. Unpruned control

Spacing was 30 feet between rows and between trees

in the row, and trees were hedged 7 to 9 feet from the trunk and

topped with a rooftop cut peaking at 30 feet. The orchard was in

a severe alternate-bearing pattern at the beginning. Clearly, the

hedging of all trees in the first year at the beginning of the

experiment, coming into an off year, did nothing to alleviate

alternate bearing and may have made it worse.

The first year, all treatments produced less than 1,000

pounds per acre, about 800 pounds per acre on average and

statistically the same. Then the second year, all treatments

resulted in overproduction and resulting poor quality.

Only when hedging occurred prior to an on-year, then

trees were not hedged coming into the following off-year, did a

favorable pattern emerge. This progression occurred with

treatment 3 coming into the 2009 on-year crop. In this case, the

hedging prior to an on-year, successfully tempered the 2009 crop

from excessive to a manageable 1,900 pounds or so, with good

quality and large size.

The following off-year, the tempering of the on-year

crop the year prior enabled the trees and that treatment to set

the highest yield among the treatments in the following off-year.

Similar results from grower experience in both the West and East

lead us to believe that this result is what can be expected.

The take-home message is when hedging results in

reducing excessive crop, which occurs if hedging is prior to "on"

years, the trees are favorably impacted with quality

improvement, followed by higher "off'-year yields. When

hedging is done prior to an off year, the short crop can become

even shorter, and the rebound on-year crop even larger, either

not changing or even worsening alternate bearing.

Perhaps in alternate-bearing orchards, the hedging

program should begin only coming into expected on-years. And,

the degree of hedging, that is how much to cut the tree and how

many trees to cut, should be tempered according to historical

yield records. Cut more when the alternate bearing is severe and

the crop is expected to be very high. Delay cutting, or cut less,

coming into off-years. Once alternate bearing has been

minimized, more flexibility on when to hedge can be exercised.

In the Southeast, a similar effect is achieved from tree

removal. If you renovate an older orchard that is in an alternate-

bearing pattern, the most favorable results are achieved when

you cut the trees coming into an on-year. The remaining trees are

opened up to new light, enabling better sunlight exposure so

that more energy is produced to help fill the heavy crop, and to

produce more carbohydrates which increases the likelihood of a

higher off-year crop.

Also, there's more soil for the roots of the remaining

trees to explore, now that their competing neighbor trees are no

longer competing. When you bolster this on-year improvement

in light and soil even further with increased inputs, the favorable

impact is magnified. Use more fertilizer, better pest control,

especially of leaf-damaging pests in the on-year when the trees

need help. In one orchard done this way, which I call "turning up

the heat in the on-year", the off-year crop was improved 45

percent following high production and quality the previous on-

year.

Some orchards appear to be not alternate bearing

badly because some rows are zigging while other rows are

zagging. That is timing of hedging varied by row, resulting in

Hedging - powerful tool for crop load management

7

some rows alternate bearing badly. Those would likely be

the rows hedged coming into an off year. The rows hedged

prior to on years, would likely be alternate bearing less, or

perhaps in another cycle.

We believe the orchard performance could be

improved by getting more of the trees overall in the orchard

with consistent even production. A lot more research needs

to be done. Perhaps hedging one side of the tree, on more

rows, would open it up enough to light and reduce the

excessive crop sufficiently. Perhaps selective individual

tree crop thinning could fine-tune the orchard to get a high

percentage of the trees with lower alternate bearing.

Hedging is a standard practice in the West, and is

becoming so among large growers in the East as well. It is a

powerful tool, and your orchard performance can be

improved greatly if you manage it right. <

8

Placing and cost of an ADVERTPlasing en koste van 'n ADVERTENSIE

EEN KLEUR (SWART) · ONE COLOUR (BLACK)

A4 · Full Page · 190x270mm · R1200.00 · *R4200.00

A5 · Half Page · 190x130mm · R900.00 · *R3000.00

A6 · Quarter Page · 90x130mm · R500.00 · *R1800.00

A7 · Eighth Page · 90x70mm · R350.00 · *R1100.00

Classified · R9.00 per woord*Plasing van dieselfde advertensie in al 4 Kwartaallikse Nuusbriewe

VOLKLEUR · FULL COLOUR

A4 · Full page · 190x270mm · R2700 · *R9800

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A6 · Quarter page · 90x130mm · R1400 · *R4900

A7 · Eighth page · 90x70mm · R700 · *R2400*Placing of the same advert

in all 4 Quarterly Newsletters

----------------------------------------------------------------------------------------------

SPERDATUMS vir 2015Somer 2016 - Januarie 2016

Herfs/Winter 2016 - April 2016

Lente 2016 - Augustus 2016

-----------------------------------------------------------------------------------------------

· Please post, fax or email your advertisement to

the SAPPA office. Clearly highlight which ADVERT SIZE

you would like and whether or not you want it

advertised once or four times.

· Pos, faks of epos jou advertensie asb. na die SAPPA kantoor.

Maak asb. duidelik watter ADVERTENSIE GROOTTE u wil hê en

of u dit een keer of vier keer wil adverteer.

-----------------------------------------------------------------------------------------------

PAYMENT PROCEDURE · BETALING PROSEDURE

· Pay the amount you owe directly into:

SAPPA. FNB. Branch 200110. Acc.No. 6254 3021 133.

VAT No. 4060270263

Then send your advert, your chosen advert format and your

proof of payment to the SAPPA office.

· Betaal asb. die bedrag wat u skuld direk in:

SAPPA. FNB. Tak 200110. Rek.Nr. 6254 3021 133.

BTW Nr. 4060270263

Stuur dan u advertensie, advertensie grootte en

depositostrokie na die SAPPA kantoor.

Hedging - powerful tool for crop load management ...continued

PEKAN PLAAS TE KOOPPretoria - Onderstepoort - 4.3ha Pekan plot

300 Pekan bome 30 jaar oud

Groot 4 slaapkamerhuis, 3 badkamer, 3 leef areas,

2 x woonstelle, (2 ½ kamer + 1 kamer), 6 motorhuise.

Baie sterk water. Gesoneer vir Industriële gebruik.

5km vanaf Universiteit. Inkomste R300k-R600k per jaar.

Prys - R3.3 miljoen

Kontak Charl Yazbek by 012 561 3777/8 of

082 893 6015 of epos cyaz@wbs.co.za

9

Die konsep “biologiese beheer” vind al hoe meer aanklank by produsente, gegewe faktore soos weerstand by sekere plae teen chemiese middels, omgewingsbesoedeling, gifresidue op produkte, stygende kostes van insekdoders asook die onttrekking van sekere insekdoders vanuit die agro-chemiese bedryf.

Biologiese beheermetodes kan help om hierdie probleme aan te spreek en is veral binne 'n geïntegreerde beheerprogram van waarde waar dit die gebruik van tradisionele chemiese metodes ondersteun.

Dit is belangrik om daarop te let dat die doel van biologiese beheer, nie soos in die geval met chemiese beheer, die uitwissing van die plaagpopulasie is nie, maar wel om die populasie onder die skadelike drempelwaarde te hou. Daar word dus gestreef na 'n balans tussen die plaag en sy natuurlike mortaliteitsfaktore in 'n gegewe omgewing.

Biologiese beheermetodes sluit 'n hele verskeidenheid opsies in, waaronder feromone, afweer- en antivoedingsmiddels, natuurlike vyande, asook biologiese “toksiene”, ressorteer. Onder natuurlike vyande word algemeen verwys na die drie “P's”, naamlik patogene, predatore en parasitoïede.

Hierdie artikel is die eerste in 'n reeks van drie waar elk van die drie vyand-tipes in meer detail bespreek word.

Insekte, net soos die mens, word ook deur verskeie siektes geteister. Die organisme (mikrobe) wat die siektetoestand by die insek veroorsaak, staan bekend as 'n insekpatogeen. Hierdie patogene sluit swamme, bakterieë, virusse, protozoa en nematodes in.

Die gebruik van patogene kan binne die raamwerk van produkgebaseerde en/of bewarings-biologiese beheer plaasvind. Vervolgens, 'n kort oorsig van elk:

Tradisioneel word insekdoders in die vorm van 'n (chemiese) produk, hetsy as vloeistof-, korrel-, of poeierformulasie, toegedien. Die ontwikkeling van “biologiese” produkte vir gebruik teen insekplae het die afgelope paar jaar geweldige vooruitgang getoon, veral ten opsigte van mikrobiese insekdoders.

Die mees omvattende publikasie in hierdie verband is The Manual of Biocontrol Agents wat nou ook aanlyn beskikbaar is (sien www.bcpcdata.com). Plaaslike produsente word deesdae al hoe meer gekonfronteer deur verteenwoordigers van maatskappye wat daarop aanspraak maak dat 'n nuwe biologiese of organiese insekdoder nou op die Suid-Afrikaanse mark beskikbaar is.

Alhoewel baie van hierdie produkte een of ander “organiese” sertifisering dra, moet produsente daarop let dat alle insekdoders, hetsy chemies of biologies, onder die Suid-Afrikaanse Landbouwet 36 van 1947 geregistreer moet wees alvorens verkope daarvan wettig is.

Patogene

Produkgebaseerd

Registrasie onder hierdie wet behels dat 'n unieke “L” nommer aan die produk toegeken word. Produsente kan daarop aandring dat hierdie “L” nommer aan hulle uitgewys word. Aangesien effektiwiteitsproewe as deel van die registrasie uitgevoer moet word, bied registrasie aan die kliënt 'n mate van sekuriteit dat die middel/produk wel werk.

Produsente kan gerus 'n kopie van A guide for the control of plant pests by die Departement van Landbou aankoop (Direktoraat Kommunikasie, P/Sak X144, Pretoria, 0001), waarin alle geregistreerde insekbeheermiddels verskyn.

'n Verkorte weergawe is ook op die internet beskikbaar by: http://www.nda.agric.za/doaDev/sideMenu/ActNo36_1947/AR/Insecticides.htm. Die webtuiste http://www.croplife.co.za kan ook gebruik word om hierdie inligting te bekom.

Figuur 1: Skematiese voorstelling van die swam Beauveria bassiana. MS Rakotonirainy, CRCC, http://mycota-crcc.mnhn.fr

Figuur 2: Infeksie-siklus van 'n swam op 'n plantluis.

JUSTIN HATTING, LNR-KLeingraaninstituut

Voorbeelde van aktiewe bestanddele wat as lewendige entiteit in Suid-Afrika geregistreer en bemark word, sluit die twee swamspesies Beauveria bassiana (Figuur 1) en Metarhizium anisopliae in. Beide hierdie twee swamme word as lewendige spore geformuleer en bemark. 'n Virus in die familie, Baculoviridae, is ook onlangs geregistreer teen die valskodlingmot wat bekend staan as die Cryptophlebia leucotreta “granulovirus” of te wel CLGV.

Soos genoem kan mikrobiese toksiene ook as biologiese insekdoders gebruik word, soos in die geval van die bakterieë Bacillus thuringiensis (of te wel Bt) en Saccharopolyspora spinosa. In die geval van Bt word 'n proteïengebaseerde endotoksien geaktiveer onder die unieke pH-toestande in die insek se spysverteringstelsel.

Bt-gebaseerde insekdoders is daarom nie 'n lewendige produk soos in die geval van bogenoemde swamme nie. Na toediening moet die insek die toksien fisies inneem (aktiewe voeding) om effektief te wees. Verskeie rasse van Bt bestaan waarvan die bekendste kurstaki en aizawai is.

Beide hierdie rasse is in Suid-Afrika geregistreer en word algemeen toegedien teen wurmplae soos die bekende bolwurm en ruitrugmot op groente en die Plusia-looper of koolvalslandmeter-ruspe op groen-, soja- en droëbone.

Ander rasse sluit in israelensis teen muskietlarwes en tenebrionis teen kewerlarwes. 'n Ander toepassing van Bt is die gebruik van die Bt-geen in geneties gemodifiseerde gewasse wat dan self hierdie toksien produseer om die plant weerstandbiedend te maak teen insekte wat daarop voed. ‘n Voorbeeld hiervan is Bt-mielies wat weerstand bied teen mieliestamrusper en Chilo-boorder. Insekpopulasies wat voortdurend op die Bt-mielies voed, verkeer onder seleksiedruk en kan egter 'n weerstand ontwikkel teen die toksien.

Plantluise, soos die Russiese koringluis (Diuraphis noxia) en hawerluis (Rhopalosiphum padi), is belangrike plae op koring en ander kleingrane. Hierdie insekte voed met spesiaal-aangepaste monddele binne die

gasheerplant waar hulle sappe uit die plantselle onttrek.

Die enigste patogene wat effektief teen plantluise optree, is swamme, aangesien hierdie mikrobes direk deur die plantluis se vel (kutikula) kan penetreer (Figuur 2) en nie soos bakterieë of virusse geëet moet word om infeksie te veroorsaak nie.

Die gebruik van swamme, soos B. bassiana teen plantluise (Foto 1) is wel 'n moontlikheid, maar aangesien plantluispopulasies die vermoë het om baie vinnig toe te neem, is die effektiwiteit van hierdie swam effe beperk.

Navorsing by die LNR-Kleingraaninstituut (LNR-KGI) fokus nou op die gebruik van B. bassiana (en ander spesies) in kombinasie met 'n sub-dodelike dosis van 'n chemiese insekdoder. Die kombinasie het 'n sinergistiese werking waar die swam die insek siek genoeg maak om meer vatbaar vir die insekdoder te wees, terwyl die middel die insek genoegsaam stres om meer vatbaar vir die swam te wees.

Verskeie insekdoders is reeds geïdentifiseer as verenigbaar met hierdie swamme en sal voortaan onder glashuis- en veldtoestande getoets word.

Hierdie konsep is daarop gemik om die bestaande populasie van voordelige organismes in 'n omgewing te bewaar, aan te help en/of te manipuleer deur die korrekte produksiepraktyke te volg.

Gegewe die beperkte beskikbaarheid van geregistreerde mikrobiese insekdoders tans in Suid-Afrika, kan produsente onafhanklik hierdie metode van biologiese beheer toepas. Die sukses van die metode is opgesluit in die bewaring van die totale kompleks van voordelige organismes in 'n spesifieke omgewing.

Hierdie organismes sluit dan die drie “P's” in. Bewaringsbeheer behels (1) habitat/landskap manipulasie, (2) bewustheid van en korrekte

Bewarings-biologiese beheer

1: Gevleuelde Russiese koringluiskadawer met die swam Beauveria bassiana besmet. Foto: JL Hatting, LNR-KGI2: 'n Koringaar met plantluiskadawers besmet met die swam Pandora neoaphidis. Foto: JL Hatting, LNR-KGI3: Kadawer van die Afrika-bolwurm met die swam Nomuraea rileyi besmet. Foto: JL Hatting, LNR-KGI4: Kadawer van die Afrika-bolwurm, Helicoverpa armigera, met virus besmet. Foto: JL Hatting, LNR-KGI

10

uitkenning van plae en hul natuurlike vyande, (3) beperkte gebruik van plaagdoders en/of (4), die gebruik van selektiewe plaagdoders of die gebruik van plaagdoders op 'n selektiewe wyse ten einde die funksionele biodiversiteit in 'n gegewe omgewing te promoveer.

Kategorie (3) en (4) is veral belangrik, aangesien voordelige organismes baie sensitief is vir plaagdoders en daarom moet die gebruik daarvan slegs plaasvind wanneer die betrokke plaag sy ekonomiese skadelikheidsvlak bereik het. Om hierdie vlak te bepaal word die volgende formule gebruik:

Ekonomiese skade (kg/ha) = Beheerkoste (R/ha) x 2 Produkprys (R/kg)

Dus is ekonomiese skade die plaagpopulasievlak waarby chemiese beheer 'n opbrengstoename teweeg sal bring wat gelykstaande is aan twee maal die koste van beheer.

By koringproduksie is daar ongeveer ses voordelige swamspesies wat natuurlik in die ekosisteem voorkom en wat plantluise parasiteer. Proewe deur die LNR-KGI het gevind dat swamme soos Pandora neoaphidis (Foto 2), Conidiobolus thromboides en C. obscurus uiters sensitief is vir 'n reeks swamdoders, veral dié (byvoorbeeld bensamidasool- en triasooldoders) wat algemeen gebruik word teen roessiektes, soos Puccinia spp. op koring.

Soortgelyke studies oorsee bevestig hierdie negatiewe impak van swamdoders op natuurlike plantluisbeheer deur voordelige swamme (sien http://ipmworld.umn.edu/chapters/rrvpga.htm).

Onder besproeiingstoestande parasiteer hierdie swamme, veral die graanroosluis, (Metopolophium dirhodum) en onderdruk sodoende die luise sodat chemiese beheer selde, indien ooit, nodig is.

Die meeste produsente is nie eers bewus van hierdie gratis plaagbeheerdiens wat deur die swamme gebied word nie. Nog 'n plaaslike voorbeeld is die natuurlike voorkoms van die swam Nomuraea rileyi (Foto 3) op veral Plusia-landmeters op verskeie boongewasse en bolwurms op koring.

Soos genoem, sal die onnodige toediening van swamdoders hierdie insekpatogeen nadelig beïnvloed; wat tot 'n toename in die plaagpopulasie kan lei. Die behandeling van gewasse slegs wanneer siekte- of plaagdruk groot genoeg is om ekonomiese skade te veroorsaak of wanneer bestaande drempelwaardes oorskry word, sal die impak daarvan op voordelige organismes tot 'n minimum beperk.

Baie insekpatogene het 'n mate van selektiwiteit en is dus minder nadelig teenoor sekere van die natuurlike vyande. 'n Voorbeeld hiervan is die Bt-insekdoders wat gebruik word vir die beheer van wurm-tipe (Lepidoptera) plae.

Virusse (Foto 4) is hoogs selektief en sal ook 'n beperkte (direkte) impak uitoefen op natuurlike vyande in dieselfde omgewing. Sommige chemiese insekdoders word ook as “sagter” op die omgewing beskou, soos die aktief pirimicarb.

Die voorkoms en verspreiding van gasheerplante wat die oorlewing van natuurlike vyande in die omgewing promoveer, word tans nagevors deur die LNR-KGI. 'n Soortgelyke studie is ook onlangs in Argentinië geloots.

Opnames deur die LNR-KGI het gevind dat plantspesies soos die gewone sydissel (Sonchus oleraceus), brandnetel (Urtica urens), knapsekêrel (Bidens pilosa), wildeslaai (Lactuca erriola), purperwinde (Ipomoea purpurea), populierbome (Populus canescens) en riete (Phragmites australis), almal plantluise huisves wat ook as gashere dien vir insekpatogeniese swamme.

Die swamspore (inokulum) wat op hierdie luise geproduseer word, beweeg dan na aangeplante gewasse (byvoorbeeld koring) waar dit die skadelike plantluise infekteer. Kennis van hierdie interaksies kan in die toekoms gebruik word om die omgewing beter te bestuur/manipuleer ten einde natuurlike plaagbeheer te optimaliseer.

Habitat/landskap manipulasie kan teweeggebring word binne die aangeplante omgewing deur interaanplantings (inter cropping), gemengde aanplantings (mixed cropping), kombinasie aanplantings (companion planting) en aanlok-aanplantings (trap cropping) asook direk buite die aanplanting in semi-natuurlike areas.

SlotgedagtesDie natuur bied 'n gratis plaagbeheerdiens aan produsente deur die impak van natuurlike vyande of te wel die drie P's, nl. patogene, predatore en parasitoïede.

In die VSA word die jaarlikse waarde van hierdie natuurlike “biobeheer dienste” tussen $4,5 en $17 miljard beraam. Die maksimum voordeel kan hieruit verhaal word deur produksiepraktyke so te bestuur dat die bewaring van die natuurlike vyande altyd in aanmerking geneem word.

Onnodige en/of ontydige toediening van chemiese plaagdoders is een van grootste sondebokke. Die gebruik van biologiese insekdoders neem stelselmatig toe in Suid-Afrika en verskaffers daarvan dra die verantwoordelikheid dat die produk wettig geregistreer en van hoë gehalte is.

Produkte wat 'n lewendige entiteit bevat kan nie op dieselfde wyse as 'n sintetiese insekdoder hanteer (wat betref vervoer en storing) word nie. Oor die algemeen neem biologiese insekdoders effe langer om 'n uitwerking op die plaag uit te oefen, maar sluit ook 'n gedragsverandering in, byvoorbeeld waar 'n swam of virus toegedien word, sal die insek eers ophou voed (indirekte beheer) voordat dit vrek.

Solank daar geen voeding plaasvind nie, word verdere skade aan die gewas dus beperk. Leer ken jou (vriendelike) vyand en boer saam met die natuur!

Vir verdere navrae kontak dr Justin Hatting by die LNR-KGI by 058 307 3468 of hattingj@arc.agric.za.

11

By George Ray McEachern, Professor of Horticulture, Texas A&M

University, College Station, Texas 77840. g-mceachern@tamu.edu

Pecan South, Volume 48, No.2, April 2015

Many factors influence production and profitability but

few or none are more important than the soil on which pecans

are grown. We always say, "Pecans need deep, well-drained soil;"

but the question is how deep and how well drained? Irrigation is

important, but the water delivery and rate depends on the soil.

Soil and water go hand in hand with pecans. Amazingly, we know

and have worked with growers with less than ideal soil — but

with an excellent understanding of their soil, some have made it

work. On the other hand, some growers with good soil fail to

understand their soil and produce less than their soil potential. In

Texas, a 12-inch soil can bear 500 pounds per acre with good

management, a 24-inch soil can bear 1,000 pounds and a 36-inch

soil can bear 1,500 pounds. Very deep, well drained soils with

sufficient clean irrigation water can bear more.

Root anchorage depends on soil and roots, enough to

withstand high winds and heavy crop loads. When hurricanes or

tornados blow trees over, we learn the depth and drainage of our

soil. Following a storm, large slabs of soil and roots are pulled up

and exposed; thus we see the number and size of the roots, the

distribution of the roots, and root type, being a tap root or

fibrous root system. The classic Hugo Pape pecan tap root on the

bank of the Guadalupe River was one large tap root 15 feet deep

with large lateral roots extending out 50 feet. In contrast, when

some large 50-year-old 'Stuart' trees were blown over at the

Texas A&M orchard, the trees had no tap roots, but numerous

large lateral roots growing out of the ground-line crown.

Soil/root complex. Why do roots only grow so deep,

then fail to develop? Mature trees uprooted by a storm provide

the answer. Where there is no water, there are no roots. Where

there is no soil air, there are no roots. We all know the importance

of water, but many growers fail to appreciate the importance of

soil air, with water, on root growth. Root systems should be

dynamic, constantly generating new roots. With soil water and

air, as young roots die, new roots grow back immediately.

However, without water and air, as young roots die, no new roots

form.

Soil air. In general, we say the soil should be 50 percent

particles(sand, silt, clay), 25 percent water, and 25 percent air

(which is 21 percent oxygen). If the soil does not have sufficient

oxygen, several negative issues occur: (1) young roots die and

water absorption via osmosis stops; (2) with no oxygen, essential

nutrient ions such as nitrogen cannot be absorbed because it is

an active transport system which requires energy and oxygen; (3)

when root tips die due to no soil oxygen, the plant growth

regulator, cytokinin, is no longer produced from the root tips and

cell division throughout the tree slows or stops; and (4) when

there is sufficient oxygen in the soil, the root system can

selectively exclude' salt absorption. In short, with good soil

drainage and sufficient soil air/ oxygen, pecan roots can absorb

water and nutrients, produce cytokinin and exclude salts.

Soil depth. Most of the water and nutrients absorbed

by the tree are in the top 12 inches of soil because oxygen is

highest there. We also say that 90 percent of the water and

nutrients are absorbed in the top 36 inches of soil. However,

when one has superior soil such as those on terraces or ridges of

major rivers, absorption can be much deeper, thus more and

better. Our major rivers can have 30 feet of drained soil and our

smaller lesser rivers can have 10 feet of well-drained soil. Creeks

can have deep soil, but they can also have shallow soil. The West

Cross Timbers region of Texas has some extremely deep well

drained soil with season-long water-holding capacity and very

deep root development. East Texas upland soils are usually less

deep with limited water-holding capacity, but with irrigation can

do well.

Clay layers in alluvial soils adjacent to our major rivers

can stop the upward movement of water during periods of

drought and stop the downward movement of water during

periods of heavy rain. These clay layers can and do create

underground "perched" water tables that prevent new roots

from forming due to no soil oxygen. All river bottom orchards

have spots or areas where trees fail to grow or die; in most cases

this is due to underground clay layers.

Shallow soils hold less water and saturate faster/easier

resulting in no soil oxygen. Growers with shallow soil need to

apply only the amount of water the soil can hold. Shallow soils

also need to be irrigated more frequently to supply the volume

that has been used by the tree.

Soil texture is sand, silt and clay, or the size of soil

particles. A loam is a combination of these different particle sizes.

Sandy soils drain fast with higher oxygen potential, but have poor

water- and nutrient-holding capacity. Clay is extremely small

particles, at only 2 microns, with slow drainage but high water-

and nutrient-holding capacity. Professor Fred Brison taught me a

good lesson on soil texture; he said, "Young trees grow fast on

sandy soil; but old trees bear better on clay soils." The ideal soil

would be a deep, sandy clay loam having both oxygen and water.

Soil structure. Clay can have good soil structure or

poor, and there is a big difference. When a clay soil has good

structure, the chemistry is such that the clay particles flocculate

to form aggregates. Clay soil with good structure drains well; plus

it has good water- and nutrient-absorption potential and air can

move into and within the soil. Clay soil with good structure will

crumble when squeezed in the hand. Clay soil that has poor

structure is as hard as a rock when dry. If clay soils are irrigated

Pecan SOIL and PRODUCTION Potential

13

with high sodium water, the soil becomes deflocculated and it

begins to drain poorly and water and oxygen fail to move in the

soil. There are millions of acres of good soil in Texas that have no

pecan potential because the irrigation water contains too much

sodium. Soil scientists use a Sodium Absorption Ration (SAR) to

evaluate water for irrigation; an SAR 4 or less is ideal, an SAR of 5

to 7 is acceptable, but will need clean irrigation water or rain to

leach sodium out of the soil. An SAR 8 to 12 should not be planted

with pecans. Mature orchards with high SAR and destroyed soil

structure can be helped, not corrected, by tilling gypsum

(calcium sulfate) into the soil. At El Paso and Las Cruces, some

growers with severe sodium issues with no drainage have

worked hard to rebuild soil structure between mature pecan tree

rows. Gypsum was mixed with the sodium dead soil between

rows with a track hoe in trenches 12 feet wide and 6 feet deep. In

theory, the calcium from the gypsum will move onto the clay

while sodium will move off the clay. Clean irrigation water or

rainfall can then leach the now unattached sodium below the

potential root zone. Soil or irrigation water with an SAR 13 or

higher cannot be used for pecans.

Soil pH is the best and most important information one

obtains from a soil analysis. The ideal soil pH is 6.0 to 6.7 for most

crops. Pecan do well in a wide range of soil pH. If the soil is too

acid, ground limestone (lime) will need to be added; otherwise

there will be insufficient calcium in the soil for ideal tree growth

and production. Dolomitic limestone with calcium and

magnesium is sometimes used. On the other hand, if the soil is

too alkaline with a pH 7.9 to 8.4, the pecan root system will not

absorb sufficient zinc or iron, regardless of their level in the soil.

In the irrigated West where all pecan soils have a high pH,

ammonium sulfate fertilizer is used, because it helps lower the

soil pH. All pecans on acid or alkaline soils benefit from frequent

foliar zinc sprays, but with high pH soils zinc sprays are essential.

Compaction of soil can become a issue with repeated

heavy equipment use in the orchard. Cultivation, irrigation and

equipment traffic over time can move clay particles below the

tilled layer and create a plow pan. Growers need to dig holes in

their orchard to see if the soil is soft or hard. If the soil is too hard

to dig, it is too hard for roots to grow.

Drainage and aeration. In high dollar vineyards of

Europe, every vine row has a French drain 36 inches below the

soil line to move water out of the soil and prevent water

saturation. Golf courses and athletic fields now use plastic drain-

age pipes to prevent sub-surface soil saturation with water. Low

places within an orchard, which trap water for longer than 48

hours, would profit from improved surface drainage on

underground drainage tile. River bottom sloughs that never

drain should not be planted to pecans. When trees die in poorly

drained sites, trees should not be replanted.

Soil color in river flood plains can be an indicator of how

well the soil drains and how aerated the soil may be. In Texas

many years ago, the red soils of the high plains were transported

down the Red, Brazos and Colorado rivers to the flood plains of

East and South Texas. These are excellent soils as they tend to be

deep, well drained, and fertile. These river bottoms have ridges

or terraces that are higher than the normal floor and they are also

usually a sandy loam, two reasons that make them outstanding

pecan soils.

A special thank you goes to Jason and Jennifer Pape for

a very generous gift to the Texas A&M Pecan Orchard in honor of

their dad and friend of all pecan growers, the late Harold Pape.

We all miss Harold, he was a wealth of pecan knowledge, and we

know no one loved pecans more he. Harold was a true pecan

hero. <

Pecan SOIL and PRODUCTION Potential...continued

By George Ray McEachern - Professor of Horticulture, Texas A&M

University, College Station, Texas 77840. g-mceachern@tamu.edu

Pecan South, Volume 48, No.3, May 2015

Planting seed in place. Pecan orchards are difficult to

establish by planting seed because it requires individual tree care

for tree selection, irrigation, weed control and unwanted tree

removal. All of which occurs over a long 3 to 5 year period of time.

Though seemingly less costly, it is however the most expensive

system for planting a pecan orchard —because of the 3 to 5 years

it takes to get the trees up and growing. It is difficult to control

weeds on these small trees, which are far apart.

Grow your own nursery seedlings or grafted trees.

Some growers start by growing pecan nursery trees and planting

them to develop their own orchard. The decision to grow nursery

trees or purchase trees depends on the individual. Nursery trees

Pecan OrchardESTABLISHMENT

14

16

• Kwekery geleë in Streek 9, Petrusburg (Vrystaat):

•Boompies sal maklik in elke streek aanpas.

• Kwekery is Sappa geregistreer nr 245 en alle boompies voldoen aan Sappa Standaarde.

• Slegs uitgesoekte bome met goeie eienskappe word gebruik vir ent-materiaal.

• Ukulinga word gebruik vir onderstam. Grondvlak gemerk op stam en ook

variëteit-kleur gemerk na enting.

ADVERTENSIESAdvertisements

Variëteite beskikbaar vir Augustus 2015 aanplanting:

• Kwekery geleë in Streek 9, Petrusburg (Vrystaat):• Boompies sal maklik in elke streek aanpas.

• Kwekery is Sappa geregistreer nr 245 en alle boompies voldoen aan Sappa Standaarde.• Slegs uitgesoekte bome met goeie eienskappe word gebruik vir ent-materiaal.

• Ukulinga word gebruik vir onderstam. Grondvlak gemerk op stam en ookvariëteit-kleur gemerk na enting.

Wichita • Navaho • Choctaw

are easy to grow, but very difficult to dig after 3 years. Growers

with container nursery skills can grow their own trees with good

seedling trees produced in 2 or 3 years. The trees can be patch

bud grafted in the container before transplanting to the orchard

or the seedling trees can be transplanted and four flap or inlay

bark grafted 2 or 3 years later in the orchard. The delay in grafting

gives a grower 2 or 3 years to evaluate potential new varieties

recently available. Three or more years are needed to

successfully graft all the trees. These failed or delayed grafting

efforts result in non-uniform tree size and post-graft after-care,

which is extra work, or a problem. Though seemingly less costly,

the grow-your-own nursery tree system takes longer time and

more individual tree care, which is frequently neglected or put off

until it is too late. For this reason, growers should not attempt to

establish more than 10 acres with this system. There are many

examples of orchards that have a significant percentage of

inferior seedling trees because they were not grafted.

Planting grafted nursery trees. This is the most

common system used in the industry because it is fast, uniform,

and with less effort and worry. It is also the least costly and comes

into production fastest. Grafted nursery trees are in the adult,

not juvenile, phase of growth and require modified central leader

training. This requires knowledge and practice; otherwise, the

trees will grow as an adult with numerous scaffold limbs too

close to the ground. These multi-limb trees have problems with

tree crowding, tractor passage and shaker attachment, but with

more pecans in year 5, 6 and 7. However, with good

establishment management and central leader training, grafted

nursery trees can come into full production in seven or less years,

depending on the variety.

Transplanting via tree spades. In the irrigated West and

to a lesser degree in Central Texas, some pecan growers

intentionally plant trees too close and move every other row or

tree after 3 to 5 years. The ultra-closely planted trees are easier to

manage when young. The trees are later moved only a short

distance by using a mechanical tree spade. The soil needs to be

the same texture at both locations. Frequent tank watering or

flood irrigation will be needed at the new tree site. This system is

commonly called "orchard expansion". If for unexpected

reasons the closely spaced trees are not moved, excessive tree

crowding will result.

Production age for new orchards. Some orchards

require 10 to 12'years to come into production while others can

bear economic crops in less than 7 years. The determining factor

is the cost of harvesting —when the young tree crop income is

greater than the cost of harvesting, the trees are considered in

production. Full production for mature trees for a specific region

can be 500, 750, 1,000 or 1,500 pounds per acre and will depend

on soil, water, variety, spacing and quality of management.

Essential Factors Needed for Pecan Orchard Establishment

Orchard size and financing. A cost of $2 to $4,000 per

acre, not including the cost of the land and irrigation, is required

for orchard establishment. There are in general 3 orchard sizes:

small family orchards with no labor with 1 to 100 acres; moderate

size orchards of 100 to 500 acres with owners providing

management and limited labor and equipment; and corporate

orchards of 500+ acres with hired management, extensive labor

and equipment.

Time has value and 7 to 10+ years are required for

investment dollars without return.

Knowledge or skills with information gathering,

budgeting, record keeping, laws, labor, equipment, horticulture,

irrigation, weed control, other cash flow crops, wildlife and more

can influence orchard establishment. However, there are many

non-formally trained individuals who have the gift of "knowing

when a tree is healthy or not healthy" and they can establish a

pecan orchard fast and correctly. Information gathering is a vital

tool that should be used fully. The Texas Pecan Shortcourse,

county Extension agents, Texas A&M pecan specialists, USDA

Natural Resources and Conservation Service, fellow pecan

growers, neighbors, and more need to be utilized in obtaining

information on how to grow pecans. The day of "doing your own

thing" is history. Pecan orchard establishment is expensive and

requires time; bringing trees into production fast and correctly is

essential. All growers differ in their available time, financing,

knowledge, experience, equipment, climate, soil, varieties, etc;

therefore, they have from the very beginning been open minded

and cooperative with each and every pecan grower. This free

exchange of ideas and information needs to continue and be

utilized to its full potential.

Climate. Pecans need to be grown in a climate with 400

hours of winter chilling, and 150 growing days to flower and ripen

the crop. Early fall and late spring freezes are a concern.

Soil. Pecans need deep well drained soil. A wide range

of soil pH is tolerated. The USDA NRCS Soil Survey Maps are very

helpful in understanding pecan orchard soil.

Irrigation. Newly planted pecan trees will need moist,

not wet, soil that never goes dry. Tank watering for year 1 and 2

can deliver water when and where and the correct amount. All

forms of irrigation plus rainfall improve young tree growth.

Never saturate the soil and never allow the root zone to become

dry. Irrigation water needs to be salt free; water with an SAR of

less than 4 is ideal, an SAR of less than 7 can be managed if salt

free water or rainfall can leach the sodium out of the soil. Soil with

an SAR of more than 8 should not be planted with pecans.

Nitrogen. Once a new root system is established,

frequent small nitrogen fertilization stimulates rapid shoot

Pecan OrchardESTABLISHMENT...continued

17

growth. Ground applied nitrogen should be stopped in mid-June

to insure soil depletion of N in the fall to prevent late season

growth and potential freeze injury or death. The N rate for -

injection into a drip irrigation should never be more than one-

fourth the ground recommended rate. Foliar N in combination

with zinc can be applied until mid-August and the liquid 32

percent N should never be applied at a rate higher than 1 percent

to prevent foliage burn.

Foliar zinc. Each spring at bud break foliar zinc as zinc

sulfate powder or zinc nitrate liquid should begin. Zinc + N foliar

sprays should be applied as long as new growth is being made. It

is common for growers to spray zinc + N every 2 weeks; some

growers spray weekly. Ground-applied zinc is not effective. Zinc

chelates, zinc chloride or zinc oxide are not effective on pecans.

Weed control. Glyphosate post-emergence contact

herbicide is used to kill most grass and broad leaf weeds in

pecans. In recent years, glyphosate-resistant pig weed has

become a major issue in pecan orchards. In 2015, several ag

chemical companies will be marketing several different and new

combinations of glyphosate + 2,4-D herbicides; extreme care

must be taken to prevent 2,4-D products from contacting any live

growth on young pecan trees. Any air movement could bring 2,4-

D in contact with new growth with subsequent tree damage or

death. Grow tubes are essential in protecting young pecan tree

trunks from damage by all contact herbicides. Shallow tillage is a

good tool in controlling weeds during orchard establishment,

however it cannot be used in regions that have frequent rains.

Weed barriers can be used on plantings of limited trees, but it is

too expensive for plantings over one acre in size. Glufosinate_

though different from glyphosate, has also failed to kill

glyphosate-resistant pig weed at the A&M pecan orchard. This

resistant pig weed is a major issue and there is not a reliable

solution at this date, though the major ag chemical companies

are working hard to discover a product or combination of

products that will kill resistant pigweed. Frequent rains increase

the difficulty of controlling weeds, regardless of the system. Low

mowed sod, though competitive for soil moisture and soil N, may

be needed in combination with weed barriers at the tree when

resistant pig weed is well established in an orchard. There are

additional weeds developing resistance to glyphosate, thus

chemical weed control could become more difficult.

Young Pecan Tree Training

Fast growth is needed to properly train young pecan

trees. If the tree is not growing fast, do not attempt to train the

tree by repeated pruning. Fast tree growth is obtained by having

and/or following the above discussed factors. These factors are

more important than pruning a young tree.

Modified central leader tree training is the system

used to develop the adult growth into a central leader tree. The

tree is cut back one-half at planting. One shoot is selected as the

central leader within the top 6 inches of the cut back trunk; all

other shoots are rubbed off when they are short and easy to pop

off by hand. The selected shoot should make significant growth

the first year. If less than 12 inches of growth on the central leader

is obtained, some type of management error has occurred and

extensive pruning of short shoots should not be used. When

management is less than ideal, just keeping the first-year trees

alive is good. The most common cause of no or limited growth

the first year is failure of new roots to develop early in the

growing season.

Second-year central leader tree training. Select the

strongest shoot as the central leader and cut it back one half in

the dormant season before growth starts. The one-half cut-back

point is only on the one-year growth from last season. When new

shoot growth begins, select the strongest new shoot and hand

remove all the other shoots within 6 inches of the cut-back point.

This hand-selected shoot should make outstanding growth for

the entire growing season. This selected central leader has been

known to grow 12 feet in one year. Do not remove any side shoots

on the young tree unless they are 1 inch in diameter. If central

leader training was not practiced the first year, remove all 'V'

trunks so that the tree will have only one central leader. Do the

cut back on the strongest shoot that is only one year old.

Third-year central leader tree training. Repeat the

same training and pruning technique used in year two. Cut back

and select the central leader. As new shoots grow at the cut-back

point, remove all shoots except the selected central leader. On

the trunk, do not remove side shoots until they are 1 inch in

diameter because they produce the food that feeds the new

central leader growth. Scaffold limbs can develop 5 feet above

ground. Do not allow scaffold limbs to develop on the lower 5

foot of tree trunk. Should 'V' trunks occur, remove one so that

the tree has only one central leader. Thin out or prune out

scaffold limbs which are stacked immediately above each other.

Thin out scaffold limbs that are opposite each other on the trunk.

Tip or Suggestions When Training Young Pecan Trees.

The first year is for new root growth, so do not become too

anxious for fast shoot growth. Heavy cu-back pruning always

stimulates rapid compensatory growth on a few shoots. Tip

pruning removes the apical dominance of the terminal bud and

allows many lateral shoots. Always leave a short collar on the

trunk when a shoot is pruned off. This collar is the passage way

for food and water above and below the cut. Pruning and tree

training can be done any day of the year, not just in the winter

dormant period. It is better to prune while the shoots are small,

rather than later when major cuts will be needed. <

Pecan OrchardESTABLISHMENT...continued

18

2015 AGM · 6 & 7 November

Pongola

The program for the AGM

will include the following:

Friday 6 November:

! Morning session

! Feedback on research projects

! Guest Speaker:

! Daniel J (Dan) Zedan – USA

Dan will include the following

in his presentation:

Trends in US pecan consumption

Chinese market vs emerging markets

! Longterm market for pecans

! Afternoon session

AGM

Saturday 7 November:

Introduction to Sponsors

Field Visits

EEN VAN DIE HOOGTEPUNTE OP

SAPPA SE 2015 KALENDER IS DIE AJV!

Maak dit sommer ‘n heerlike

WEGBREEK naweek vir die hele gesin

en bespreek nou julle verblyf.

Verblyf is beskikbaar in die

Pongola omgewing.

Kontak hulle so gou as moontlik, sodat

hulle plek virjou ‘n plek kan bespreek.

ONE OF THE HIGHLIGTHS ON SAPPA’S

2015 CALENDAR IS THE AGM!

Why not make it a wonderful

GETAWAY weekend for you and your

family by booking accommodation in

the Pongola area.

Book as soon as possible to prevent

disappointment.

Akkommodasie · Accommodation

Aber Jetz B/B.....................................herbst@ananzi.co.za 0833307364

Coco Cabana B/B...............................cococabana@telkomsa.net 0344131594

Dive Inn B/B.......................................diveinn@pga.dorea.co.za 0344131439

Dweba Lapa S/C................................dwebalapa@gmail.com 0827886933

Elegant Lodge...................................info@elegantlodgepongola.co.za 0344131047 of 0836087689

Koppie Alleen B/B.............................koppie@alleenguesthouse.co.za 0832282533

Kwalala Guesthouse.........................quarto@cybertrade.co.za 0825583840

Pongola Country Lodge....................info@pongolacountrylodge.co.za 0344131352

Rose Garden B/B...............................alton@vlokkie.co.za 0845102136

The Guest House...............................info@guesthousepongola.co.za 0344132299

ALGEMENE JAARVERGADERINGANNUAL GENERAL MEETING

23

By Richard Heerema and Jim Walworth Heerema is a pecan specialist at New Mexico State University,

rjheerem@nmsu.edu.

Walworth is a soil science professor at University of Arizona,

walworth@ag.arizona

Pecan South, Volume 48, No.4, June 2015.edu.

One of the most serious challenges for pecan

producers out here in the southwestern growing region is

maintaining adequate micronutrient nutrition of the trees.

Micronutrient imbalances are common with pecan trees

everywhere they are grown, but they are particularly difficult to

manage in the arid/semi-arid western U.S. because of the nature

of the region's soils. While soils in most pecan growing areas

worldwide tend to be near neutral or acidic (pH < 7.0),

southwestern soils typically are calcareous (i.e., lime containing)

and alkaline, often with pH levels of 8.0 or above. Even if an

alkaline soil contains high levels of micronutrients such as zinc,

iron, manganese, copper and nickel, these nutrients are very

poorly available because of the soil pH. Applying acids or

acidifying fertilizers to soils to increase micronutrient availability

is sometimes practiced, but is really only effective temporarily in

most western soils because of their high buffering capacity

against changes in pH.

Among the micronutrients, deficiencies for zinc are

particularly common in pecans grown on alkaline soils. Fenn et al.

(1990) studied the effects of soil pH on zinc availability in a South

Texas soil and found that water extractable soil zinc decreased

from 394 ppm down to only 12 ppm as soil pH increased from pH 4

to pH 8. Providing sufficient zinc as a soil-applied fertilizer is

difficult in calcareous soils such as those found in the

southwestern U.S. because of the extremely low solubility of zinc

in alkaline conditions, and additionally because carbonate

minerals complex to zinc in the soil — including any zinc added in

the common zinc salt fertilizers (like zinc sulfate). As a

demonstration of the difficulty, Storey et al. (1971) showed that a

soil application of over 250 pounds of zinc sulfate was needed to

provide adequate nutrition for a single pecan tree growing in a

calcareous soil! Of course, that's just not a practical solution in a

commercial pecan orchard. Not all pecan cultivars are created

equal when it comes to zinc deficiency. 'Wichita' and 'Pawnee',

for example, are far more susceptible to zinc deficiency problems

when grown in alkaline soils than is 'Western' (aka `Western

Schley') and they require much more vigilance with zinc

management. As most experienced pecan growers are already

aware, zinc deficiency symptoms in pecan trees appear as small

leaves and short internodes (the distances between buds on a

shoot) giving the shoots a kind of "rosette" appearance. In the

early part of the growing season, the leaves of zinc-deficient

pecan trees have a distinctive wavy margin and light green color

with darker green tissues near the veins. As the season

progresses, the leaf symptoms often get more extreme and the

eventually dark brown dead blotches appear between the leaf

veins, especially toward the bases of the leaflets. Zinc deficiency

leads to poor tree survival, growth and establishment in young

orchards — even mild deficiencies can add years to the time

between planting and harvesting the first significant nut crop. In

bearing pecan orchards with zinc deficiency, branch dieback

occurs, the number of female flowers that appear in the spring

drops off dramatically, and kernel development is weak,

ultimately affecting nut yield and profitability. Due to the

difficulty of supplying zinc via soil applications in the Southwest,

foliar zinc application has become the standard practice in the

Southwest. Zinc sulfate, oxide or nitrate is sprayed directly on the

pecan foliage beginning early in the season, repeated every 1-3

weeks until shoot and leaf growth has subsided. A total of 3 to 5

applications are typically required for mature trees, depending

on cultivar and soil conditions, whereas rapidly growing young

trees may require as many as 14 annual applications. Repeated

applications and excellent canopy spray coverage are critical

because, once it has been absorbed by a leaf, zinc from foliar-

applied zinc salt fertilizers does not move to other parts of the

tree or even within the leaflet tissues.

The expense, inconvenience, and inefficiency of foliar

zinc application have created strong interest amongst

southwestern pecan growers in developing an effective method

for management of zinc nutrition though soil fertilizer

applications. Since 2011 we have been evaluating the possibility

of applying zinc fertilizers dissolved in irrigation water to meet

the zinc needs of immature 'Wichita' and 'Western' trees in a

southeastern Arizona orchard with soil pH 8.1. Chelated zinc (zinc

chemically bound inside a "claw-shaped" organic molecule) is

less subject to the reactions that occur in calcareous soils than

zinc from zinc salts (like zinc sulfate). We used zinc chelated with

EDTA applied through a micro sprinkler irrigation system at two

annual rates, 2 and 4 pounds zinc/acre (in case you're curious,

EDTA stands for ethylenediaminetetraacetic acid — let's just call

it EDTA). For comparison, we had an untreated control that

received no soil-applied zinc fertilizers. Also, no foliar zinc

fertilizers were applied to any of the treatments or the control in

this trial. We recorded effects of these treatments on the tree

tissue zinc concentrations, tree zinc deficiency symptom

severity, growth responses, nut production and photosynthesis.

Both cultivars exhibited elevated leaf tissue zinc

concentrations in response to fertigated zinc EDTA. In general,

'Western' had higher leaf zinc concentrations than 'Wichita'

(Figures 1 and 2), which is testimony to the superior adaptation of

`Western' to alkaline soil. 'Western' and 'Wichita' foliar zinc levels

reached a maximum of 29 and 24 ppm, respectively, in the 4

pounds/ acre zinc treatments in 2013. In the 2 pounds/acre zinc

treatments, leaf zinc levels were 14 and 18 ppm, while the

untreated (0 pounds/acre zinc) trees of 'Wichita' and 'Western',

respectively, had only 8 and 7 mg-kg-1.<

Soil ZINC APPLICATIONS in the West can Work

24

3), fentin hydroxide (Group 30), and thiophanate-methyl (Group

1) in some orchards.

Earlier in this article I discussed pollen allergies, but

now I want to spend a little time discussing another allergy that is

not as prevalent. Unfortunately, nuts and tree nuts (including

pecan) are included in a list of 8 food groups that cause the

majority of food allergies (U.S. Food and Drug Administration,

2010). So what is actually happening when someone has an

allergic reaction to nuts? Everyone is aware that our body's

immune system provides protection against diseases attacking

our body.

When someone with a nut allergy eats a nut, proteins

are released as the nut is digested and-our immune system

misguidedly recognizes these proteins as a threat to our bodies.

Our immune system overreacts which leads to an allergic

reaction in which chemicals like histamine are released by our

body. This leads to typical allergy symptoms of wheezing,

coughing, throat tightness, vomiting, diarrhea, swollen eyes, and

in severe cases can cause a drop in blood pressure. A severe

reaction is known as anaphylaxis (pronounced an-uh-ful-LAX-is)

and if not treated quickly, it can be life threatening. The primary

treatment for an anaphylaxis is administration of epinephrine.

Nuts and tree nuts are among the highest producers of IgE-

mediated allergic reactions following food ingestion. In the

United States, food allergy produces approximately 30,000

anaphylactic reactions and 200 fatalities per year (Yocum et al.,

1999). Peanuts or tree nuts cause more than 80 percent of these

reactions.

Tree nut consumption is a healthy dietary habit and

several studies have shown that nuts are high in antioxidants and

have a beneficial effect on the outcome of coronary disease and

cholesterol serum levels (Morgan and Clayshulte, 2000; Rajaram

et al., 2001; Haddad et al., 2006). In the last few years there has

been an increase in nut and tree nut consumption because of

their favorable health effects. This has led to nuts being used in

an ever increasing array of fresh and processed foods. The

increased incorporation of nuts in processed foods may facilitate

contamination of other food products being handled in the same

food manufacturing line (Teuber et al. 2003). Thus, there is an

increased chance of accidental nut ingestion for those trying to

avoid nuts. The Food Allergen Labeling and Consumer Protection

Act passed in 2004 requires that nuts be included on the label

when they are used as ingredients in a food product. However, I

receive almost daily alerts of product recalls because of

undeclared allergens on the product label.

One way we may be able to find new solutions for those

who suffer from food allergy is to develop a better

understanding of allergen synthesis in crops. This has led to the

USDA and LSU AgCenter scientists joining forces to study the

By Charlie GrahamLSU Pecan Extension Specialist, Red River Research Station, Bossier City,

LA. cjgraham@agcenter.lsu.edu

Pecan South, Volume 48, No.4, June 2015

As I sit down to write this article, the spring season is

coming to an end. Catkins have come and gone, and most trees

are finished shedding pollen for the year. Normally, I would have

spent the last couple of months watching my wife and kids suffer

through another miserable allergy season in Louisiana. But this

year was not as bad as years past and you might be wondering

why this year was different than others. The short answer is R-A-I-

N! And while we have had above average rainfall, more

importantly, it has rained often. Since March 1, not only has it

rained at-least one day each week, more often,. it rained on 3-5

different days each week. So, there have been only a few

opportunities for pollen to blow around in the air before the next

rain shower came through. While it has been a blessing for allergy

sufferers, it is a cause for concern for pecan growers.

Wet weather in April and May can result in a poor pecan

crop set. Rain can restrict pollen movement by wind and wash

pollen off of flowers before it can germinate and penetrate the

stigmatic surface. It generally takes about an hour for pollen to

become fully hydrated on the stigma and an additional 3 hours

for it to germinate. Fruit drop occurring from 14 to 45 days after

pollination is widely considered to be due to problems with

pollen availability or to self-pollination by a cultivar. By the time

this article is published next month, we should be able to

determine what effect the rainy weather had on fruit set.

Hopefully enough pollen was shed between rain

showers to set a good crop, but protecting it will be an issue if the

current weather patterns continue. Frequent rain storms and

warm weather will provide almost perfect conditions for the

development of pecan scab on the leaves and nuts. Growers

needed to get out several early season fungicide applications this

year, but many orchards were too wet to get the ground air-blast

sprayers in the orchards. This led to some growers only getting 1

or 2 sprays out.

Some growers opted for aerial application of fungicide

and zinc. This usually works well in early season when the canopy

is still developing, but will be less effective as the leaves mature,

blocking movement of the fungicide through the canopy. We

have already seen a considerable amount of scab lesions develop

on susceptible cultivars such as 'Desirable'. With an increase in

the number of fungicide sprays required to protect the crop this

year, growers need to be diligent in rotating the chemical groups

they are applying through the season. The continuous use of the

same chemical group will lead to scab developing resistance to

that family of fungicides. Following several wet years, -Georgia is

reporting scab resistance development to propiconazole (Group

27

Has RAIN Washed AWAY the Pecan Crop?

allergens present in pecan nuts. To better understand this

collaborative research, it may be helpful to take a quick refresher

course in plant genetics. The plant genome is made up of

deoxyribonucleic acid (DNA), a long, winding, double-helical

molecule that contains the instructions needed to build and

maintain cells. For these instructions to be carried out, DNA must

be transcribed (converted) into corresponding molecules of

ribonucleic acid (RNA), referred to as transcripts. A

transcriptome represents the very small percentage of the

genome that is transcribed into-RNA molecules.

There are various kinds of RNA in a plant. The major

type, called messenger RNA (mRNA), plays a vital role in making

proteins. In this process, mRNA transcribed from genes, which

include the protein-coding parts of the genome, is delivered to

ribosomes. The ribosomes read, or "translate," the sequence of

the chemical letters in mRNA to' assemble building blocks called

amino acids into proteins. Each mRNA is transcribed from a gene

and then translated into a specific protein.

The process of determining the genetic codes

contained in the transcriptome and their relative proportions is

known as transcriptome sequencing. Once a transcriptome has

been sequenced, we can use the information to identify which

parts of the genome are used to code for active genes. If several

transcriptomes are sequenced under different growth or

environmental conditions, we can study these transcriptomes

and start to determine which genes are involved in various

biological processes. This might include the identification of

genes important for the nutritional, sensory, or yield

characteristics of pecan nuts, or the reponse of trees to pests or

drought conditions.

"Major" food allergens are typically water-soluble

glycoproteins 10 to 70kD in size that are relatively stable to heat,

acid, and proteases. Three conserved seed-storage proteins

from the prolamin and cupin superfamilies, including 2S albumin,

7S vicillin, and 11S legumin are commonly identified as allergens in

nuts. The first step in the collaborative research between the

USDA and LSU AgCenter was to investigate the timing of gene

expression of genes encoding 3 highly conserved, allergenic

seed-storage proteins in developing pecans.

Mattison et al. (2013) measured the transcript levels of

the Car i I and Car i 4 genes as well as the Car i 7S homologue over

the course of kernel development (August through October) in

the pecan cultivars `Desirable' and 'Sumner' using reverse

transcription quantitative polymerase chain reaction (RTqPCR).

Both cultivars generally had similar levels of transcripts

throughout kernel development, except 'Desirable' had higher

levels of Car i 1 and Car i 4 in August. However, transcript levels for

the tested pecan allergens varied during nut development.

In the future, results such as these could be applied to

transcriptional control methods to reduce or eliminate allergens

28

Has RAIN Washed AWAY the Pecan Crop?...continued

STREEK 7Vergaderings 2015

Streeksvergaderings het vroeg afgeskop hierdie jaar.

Beide die vergaderings is in die eerste kwartaal van die jaar

aangebied. Die hoofrede hiervoor was om die opdrag van die AJV

2015, tov behoeftebepaling vir hernuwing van statutêre

maatreëls, uit te voer.

Coligny

Dit het al gewoonte geword om ten minste 2

vergaderings per jaar in Streek 7 te hou – een in die weste en een

in die ooste. Na 'n uiters suksesvolle vergadering op Skeerpoort

in 2014 was dit die “westelikes” se beurt om die vergadering aan

te bied. Daarom is die eerste vergadering op 21 Februarie te G.

Schutte Landgoed anderkant Coligny, op pad na Lichtenburg,

gehou. Ons het ook gehoop om een of twee van die slim

amerikaners te kaap, wat dieselfde dag sou arriveer om later as

gassprekers by Die 2de SA Pekanneut Konferensie op te tree.

Maar helaas, ons was blykbaar bietjie vinnig vir hulle en hulle het

nog vlugflouheid onderlede gehad.

Kyk, die manne van Wes-Transvaal stem nie maklik in

om klomp vreemdes op hul plase te ontvang en te onthaal nie,

maar die dag as hulle dit doen, dan doen hulle dit met oorgawe.

Die kantoor word ingerig om registrasies maklik te hanteer –

geen lang toue. Die stoor word skoongemaak, tafels en stoele

netjies uitgepak – selfs tafeldoek en blomme vir voorsitters-tafel!

Daar was ook genoeg spasie binne die stoor vir Bill Vogts se

bussie met Löwe en Silky produkte.

Die lapa word spesiaal reggemaak om gaste te onthaal

na afloop van die amptelike verrigtinge – dan word daar

behoorlik gekuier! Na afhandeling van die amptelike SAPPA

verrigtinge, en 'n mandaat vir hernuwing van statutêre

maatreëls, het Hardus du Toit ons toegespreek oor

Boordbestuur. Soos Hardus self ook gesê het, dis 'n wye

onderwerp waaroor lank gesels kan word, maar as gasspreker

het hy homself goed van sy taak gekwyt. Sy benadering het goed

aanklank gevind by die produsente in die sin dat hy die

bespreking oopgegooi het en gevra het vir spesifieke kwessies

oor boordbestuur waarmee produsente sukkel in die westelike

streek. Op 'n stadium het Hardus kompetisie gekry van 'n harde

reënbui wat druis op die dak. Maar in Wes-Transvaal is ons altyd

dankbaar vir die reën.

Navorsing, biologiese vs Chemiese bemesting het baie

aandag gekry tydens die bespreking asook snoeipraktyke tydens

die boordbesoek.

Gerhard, Mariëtte dankie vir julle wonderlike

gasvryheid, op tipiese Wes-Transvaalse manier. Die G.Schutte

landgoed is beslis nou een van die venues vir toekomstige

vergaderings. Baie dankie aan ons produsente vir getroue

ondersteuning en aktiewe deelname. Dankie aan die borge:

Agrico, Arbor Supply, Senwes, Valtra.

Magaliesburg

Presies 'n maand later het ons op 21 Maart 2015 by

Zandfontein Family Organics bymekaargekom vir 'n fokus op

Pekanboom kwekerye en boomstandaarde.

30

Hennie en Nelia, dankie dat julle reggestaan met

verwelkoming en spyseniering.

Dankie aan al ons produsente en borge vir die getroue

ondersteuning van ons boeredae.

?Arbor Supply

?Delta Chemicals

?Elandsdraai Pecan Growers

?Hytech besproeiing

?IPAK

?RovicLeers

?Skeerpoort Pekans

?Zandfontein Organics

<

Dries Duvenhage (Streek 8)

Ek was nogal in die knyp met 'n gasspreker vir die

geleentheid, maar 'n ou staatmaker in ons geweste, Oom Juri

Bezuidenhout, het tot my redding gekom en my in kontak

gebring met Willem J. Kruger van Delta Chemicals.

Willem het 'n vriend, Dr. De Buys Scott, al die pad van

Bethelehem saamgebring om met ons te kom praat oor

voedingsbehoeftes van pekanneute, spesifiek mikro-elemente

en die vorme daarvan.

Dr Scott is waarskynlik meer bekend vir sy werk by die

Klein Graan Instituut en sy handboek oor “Wheat Diseases in

South Africa”. Maar, hy het 'n baie toepaslike lesing gegee en

geillustreer hoe Sinkchloried, as alternatief tot die tradisionele

toepassings van sink, aan die sinkbehoeftes van pekanneute kan

voldoen.

Gaste is op bees-sleepwaens gelaai op 'n begeleide toer

deur Gavin Amos en Hennie Schutte deur die kwekery, erdwurm-

aanleg en die boord.

Hennie is Gavin se nuwe regterhand op die plaas en hy

maak reeds 'n groot verskil. Ons sien dit in die kwaliteit

pekanbome wat gelewer word!

31

STREEK 7Vergaderings 2015

LIST OF MEMBERS of the National Council of Representatives of the SAPPA

National Chairman pecanpro@cybertrade.co.za · 082 553 7831

Region·Streek 1 IVAN OTTO ivan@dgsd.co.za · 082 563 6690

Region·Streek 2 ALBERT BOUWMEESTER abbybouw@lantic.net · 083 302 2413

Region·Streek 3 HEIKO MEIER pecanpro@cybertrade.co.za · 082 553 7831

Region·Streek 4 MORNE ROSSmorne@greenvalleynuts.co.za · 082 789 3202

Region·Streek 5 PHILIP ANTROBUS philip@r63 · 082 560 7696

Region·Streek 6 JOHAN COETZEE johan@pekan.co.za · 082 577 4981

Region·Streek 7 HANRU PIENAAR hpienaar@adept.co.za · 082 555 9826

Region·Streek 8 DRIES DUVENHAGEduven@lantic.net · 082 948 2933

Region·Streek 9 GIDEON VAN ZYL gideon@lantic.net · 082 948 2022

Tegniese Beampte HARDUS DU TOITsappahardus@gmail.com · 083 465 6522

Transformasie Koördineerder ANDRÉ COETZEEandrecoetzee@hortgro.co.za · 083 271 6577

HEIKO MEIER Visit www.sappa.org.za for a more detailed map

33

34

By Lenny WellsExtension Pecan Specialist, University of Georgia, Tifton, GA.

lwells@uga.edu. Pecan South, Volume 48, No.6, August 2015 (pg. 4)

Fungicides do most of the heavy lifting regarding scab

control and we often tend to focus all of our attention on

fungicide selection when battling scab. But, there are many more

factors that go into protecting a crop from disease. Coverage, for

example, is vitally important. If you don't cover the nuts with

fungicide, you can't expect it to work. If you have good scab

control from the bottom of the tree up to about three fourths of

the way from the top, the problem is coverage and not the

fungicide you are using.

Dr. Katherine Stevenson's fungicide sensitivity work

has re-enforced the idea of managing our fungicides for

resistance. But, many growers automatically assume if they get

scab showing up one or two weeks behind a fungicide spray, then

the chemistry they were using is not working. This is not

necessarily true. While resistance may be a possibility, there are

other factors to consider. Testing samples from your orchard is

the only way to know if the scab in that orchard is becoming less

sensitive to the fungicide. In the meantime, take an opportunity

to examine these other factors.

Be aware of the timing of your application. How long

has it been since the previous spray? How many rains did the

orchard receive between these sprays and how soon did it rain

after you sprayed? Was the wind blowing when you sprayed? If

so, you probably didn't get the coverage you needed.

One of the most often over-looked factors I see

regarding the level of scab control a grower achieves is a

consideration of the site where the orchard was planted. Not

long ago, I spoke with a grower who had been, on a very good

fungicide program. His scab control was excellent in most

orchards but in a few orchards scab was a problem. As it turns

out, most of those orchards in which scab was becoming a

problem were smaller orchards of 30 acres or less and

surrounded by woods. The surrounding woods hold moisture in

the area and block wind, limiting airflow in the orchard. Sounds

too simple to be the source of the problem, but I've seen it many

times.

Aside from air flow, elevation is an important factor to

consider as well. Most growers know this but too often fail to

accept it as a serious issue in their own orchards. Scab-

susceptible cultivars planted in low lying areas often have serious

problems with scab. This can be readily observed by comparing

scab severity on trees on low and high ground within the same

orchards. Invariably those trees at the bottom of a slope or in a

low-lying hole will have more scab problems than those on the

higher ground.

A scab susceptible cultivar planted in a low-lying area

surrounded by woods is a recipe for scab problems no matter

what fungicide program you are using. Certain conditions may

cause the climate in one zone within an area to differ from the

surrounding areas. I believe this is one reason we see such a wide

spectrum of disease control from one area to another with

basically the same fungicides being used. The scientific term for

this is "microclimate" and it varies greatly when comparing, for

example, Albany, Georgia with Ft. Valley, or Waycross with

Americus. We often talk about the differences in the amount of

rainfall in these locations.

But, middle Georgia is on much higher ground than that

of Southwest or Southeast Georgia. Ft. Valley's elevation is 518

feet above sea level, Albany — 200 feet, Americus — 479 feet,

Waycross — 130 feet. This is why we suggest planting scab

susceptible cultivars like 'Desirable' only above Highway 280 in

Georgia. This brings to mind the thought that I've never looked at

any data regarding scab control at varying elevations to

determine what the ideal threshold may be; but if you look at

elevations above Highway 280 most are at 280 feet above sea

level or more. Perhaps we could call this the "280 Rule" — no

highly scab susceptible cultivars planted below Highway 280 or

below 280 feet in elevation.

A 100-300 foot difference in elevation can make a big

difference in the amount of moisture held in an area. As a result, it

also makes a big difference in the ability of scab to grow. It's the

difference between controlling scab on 'Desirable' with 8-10

sprays versus 15-20. You simply can't control scab in the same

manner in each of these locations due to the microclimate. But,

even with good elevation, an orchard surrounded by woods will

tend to have more scab issues than one out in the open. I met

with a grower a few years ago in middle Georgia who was having

problems with scab control in an orchard growing beside a large

block of hardwoods that sloped down to a creek. Air flow was an

obvious problem.

The decision was made to remove a portion of the

hardwoods, opening up more room for sunlight and air

movement in the pecan orchard. As a result, scab control

improved dramatically. There was no need to undergo the time

consuming and expensive task of changing over cultivars in the

orchard or changing up the fungicide spray program. Simply

taking the time to look around at the surroundings with an open

mind provided the solution.

We often get locked into a certain mind-set desiring a

quick and easy fix like changing fungicides or spraying more often

but, many times, there is more to the solution or we are simply on

the wrong track. So, if you are having trouble managing scab,

don't assume the fungicides are not working. In most cases,

Don't Underestimate VALUE OF AIR-FLOW, Elevation in SCAB CONTROL

34

Don't Underestimate VALUE OF AIR-FLOW, Elevation in SCAB CONTROL...continued

fungicide selection or efficacy is not the problem. Take a look

around at the orchard surroundings. If you are considering

planting an orchard, especially if the land has a slope to it, plant

more scab-susceptible cultivars on the higher ground and plant

scab-tolerant cultivars on the lower ground. If you have an

orchard surrounded by woods and is having trouble managing

scab, push the wood-line back if it's on your property, and allow

additional air flow into the orchard. This should improve the scab

35

36

By Lenny Wells Extension Pecan Specialist,

University of Georgia, Tifton, GA. lwells@uga.edu.

Pecan South, Volume 48, No.3, May 2015

Root dry weight typically comprises 55-70 percent of

total tree dry weight one year following transplant, which

suggests that pecan tree transplants direct most of their

resources to root establishment in the first growing season in the

orchard. Pecan trees in the first 2 to 3 years of establishment have

a limited root system compared with more mature trees, thus

their capacity for uptake of N and other nutrients is limited.

Additionally, most pecan nurseries maintain high fertility to

shorten rotation -time and increase nursery production. As a

result, trees often maintain adequate levels of N through the first

year following transplant to the orchard. So, just how much

fertilizer do young trees need?

Historically, N fertilizer recommendations for young

pecan trees in Georgia orchards have been minimal regarding the

use 'of dry, granular fertilizer. Fertigation was discouraged due to

the perceived potential for root damage from excessive

concentration of N in the root zone. The prolonged period from

tree planting to first commercial harvest of pecan provides

incentive for many growers to push young trees into commercial

production as soon as possible. This management has included

high nitrogen (N) application rates with or without fertigation.

However, until recently, there was little data regarding the effect

of N fertilization or fertigation on young pecan trees grown

under southeastern U.S. orchard conditions.

We recently completed a study comparing fertigation

with application of a complete dry fertilizer (1010-10) and dry

granular urea on first-through third-year trees, evaluating the

effect on tree growth and leaf N. We began the study with newly

planted 'Cunard' trees and second-year 'Cape Fear' trees. Rates

and response of pecan tree growth and leaf N can be seen in the

accompanying tables. Balanced granular fertilizer was applied to

"Cunard' trees once per year (9 May) in 2013 and twice per year

(25 April and 29 June) in 2014. The total volumes of UAN and

granular urea were each split into 4 equal applications on 9 May,

28 June, 12. July and 6 August 2013. For 'Cape Fear' trees,

balanced granular fertilizer applications were split into 3

applications (9 May, 28 June and 12 July) in 2013 and 3

applications (21 April, 27 May and 18 June) in 2014. The total

volumes of UAN and granular urea were each split into 4 separate

applications. Application dates were 9 May, 28 June, 12 July and 6

August 2013. During 2014, applications were made 25 April, 28

May, 29 June, 29 July. Lack of pecan tree response to fertilizer N

during the year of planting, as observed for first-year `Cunard'

trees, supports previous recommen-dations for pecan that no

fertilizer N or only a modest amount of fertilizer N is necessary for

pecan trees during the first growing season in the orchard.

Similarly, application of fertilizer N in the second and third years

following planting had minimal effects on growth or leaf N, and

there were no differences between fertigation and complete dry

fertilizer application. Thus, only a modest amount of fertilizer N is

needed in second- and third-year trees to maintain adequate

pecan tree growth and leaf N concentration. Lack of young fruit

tree response to N has been attributed to mineralized soil

organic N, low weed competition, residual soil inorganic N, low

tree N requirements, and remobilization of stored N from

fertilizer applied in the nursery. Although no direct

measurements of soil N were taken during the current study, the

soils on which the study was conducted generally retain very little

plant available N and fertilizer N is usually required for optimal

plant growth.

Therefore, it is likely that tree N reserves were

remobilized for growth of first-leaf pecan trees. Fertigation is an

effective method of applying fertilizer to pecan trees, especially

in large orchards, where additional hand labor may be required

for manual application of dry fertilizer to each tree. Fertigation at

rates up to 25 pounds/acre (split into multiple applications) for

first-year trees and 50 pounds/acre for second- and third-year

trees can be safely applied; however, such rates are unnecessary

for adequate growth and development of young pecan trees and

may result in nutrient leaching and runoff. Fertigation at rates of

10-15 pounds N/acre (split into multiple applications) would be

sufficient for first- to third-year trees. Fertigation of young pecan

trees at the above rates only seem to be a cause for concern

regarding root damage during the establishment phase if

irrigation systems are not properly maintained or flushed

following fertilizer application, allowing excessive N

accumulation in the root zone of young trees.

While there was not a consistent response of leaf P or

leaf K concentration to balanced fertilizer, the trees did appear to

respond to the balanced fertilizer treatment. This result was

likely associated with applying less N to obtain the same growth

rate. While there were minimal or no differences in trunk

How much FERTILIZER do YOUNG Pecan Trees NEED?

37

With fertigation of these nutrients, the wetted zone

may be sufficient but the larger area around it in which the roots

are trying to explore is still low. This is especially critical for P,

which plays a large role in root growth. The tree will reach a point

in which it needs sufficient P, along with K, and Zn in a larger area

for optimal growth and production. Broadcast applications

beginning with directed applications toward the herbicide strip

in young trees will help get these soil levels up to desired levels in

a broad swath around the trees. As the trees grow and leaves are

deposited in the middles, they redistribute and recycle these

nutrients back into the orchard soil. A broadcast application of

poultry litter is also a good way to elevate levels of these

nutrients in the orchard. Begin building up soil levels early on

young pecan trees in order to avoid problems down the road.

In summary, an optimal growth rate of young pecan

trees can be obtained as easily with a balanced granular fertilizer

application using significantly less N compared with fertigation

applications. The minimal treatment differences observed along

with the fact that leaf N concentration never fell below the

minimum recommended level in any treatment throughout the

study, further supports the previous recommendation that first-

year pecan trees require no N fertilizer during the year of

establishment. Only modest N application rates are required

during the second and third growing seasons. <

diameter growth between treatments, there were significant

differences in trunk diameter growth per unit of N applied

(Tables 3 and 4).

The balanced granular fertilizer treatment consistently

resulted in differences in trunk diameter growth per unit N

applied ranging from 163-900 percent over that of other

fertilization methods (Table 3 and 4). Actual N rates for balanced

granular fertilizer were between 76-82 percent lower than that of

the fertigation and granular urea treatments, suggesting such

excessive applications are unwarranted, inefficient in regard to

growth per unit of N applied, and may lead to excessive leaching

of fertilizer N into groundwater and streams. This further

emphasizes the positive benefits of minimal application of

fertilizer N to young pecan trees. We will continue this study to

address the possibility that high N rates applied early in the life of

the orchard may affect tree precocity and the profitability of

young pecan orchards within the first few years of bearing. For

this study, we applied P, K and Zn through the irrigation systemas

well. A 1-6-13 solution was used for P and K, while a 16-0-0-20 was

used for Zn. But, as young trees grow, their roots are of course

exploring the soil below, at a length twice that of the canopy

width. Therefore, the roots of a young pecan tree quickly

outgrow the area wet by the irrigation system. In newly

established orchards, this area may remain deficient of P, K and

Zn for a number of years unless dry broadcast applications are

made to bring soil levels up to the desired range.

38

How much FERTILIZER do YOUNG Pecan Trees NEED?...continued

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6

RECIPESticky-Bun Pumpkin Muffins

40

2 cups pecan halves and pieces

1/2 cup butter, melted

1/2 cup firmly packed light brown sugar

2 tablespoons light corn syrup

3 1/2 cups all-purpose flour

3 cups granulated sugar

Preheat oven to 350°. Bake pecans in a single layer in a shallow pan 8 to 10 minutes

or until toasted and fragrant, stirring halfway through. Stir together melted butter

and next 2 ingredients. Spoon 1 rounded teaspoonful butter mixture into each cup

of 2 lightly greased 12-cup muffin pans, and top each with 1 rounded tablespoonful

pecans. Stir together flour and next 4 ingredients in a large bowl, and make a well

in center of mixture. Whisk together pumpkin, next 2 ingredients, and 2/3 cup

water; add to dry ingredients, stirring just until moistened. Spoon batter into

prepared muffin pans, filling three-fourths full. Place an aluminum foil-lined jelly-

roll pan on lower oven rack to catch any overflow. Bake at 350F on middle oven

rack for 25 to 30 minutes or until a wooden pick inserted in center comes out clean.

Invert pan immediately to remove muffins, and arrange muffins on a wire rack.

Spoon any topping remaining in muffin cups over muffins. Let cool 5 minutes.<

1 tablespoon pumpkin pie spice

1 teaspoon baking soda

1 teaspoon salt

1 (15-oz.) can pumpkin

1 cup canola oil

4 large eggs

PECAN PRO NURSERY is a wholesale pecan nursery, selling to the grower for over 20 years.

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We at Pecan Pro Nursery are known for our well developed root systems.Multiple tap roots with lots of feeder roots ensure a high percentage survival of trees with transplant.

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Pecan trees can produce for well over hundred years.That's why it is important to start your pecan orchard with the best pecan trees available.

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PECAN PRO NURSERY is a wholesale pecan nursery, selling to the grower for over 20 years.

We produce the following varieties for the WESTERN REGION: Navaho, Sutex and Western.

For the EASTERN REGION we recommend:

Ukulinga, Sutex and Barton.

We at Pecan Pro Nursery are known for our well developed root systems.Multiple tap roots with lots of feeder roots ensure a high percentage survival of trees with transplant.

We take orders now for collection in August. Feel free to contact the owner Heiko Meier for any advice regarding cultivar selection,

orchard layout or pecans in general.

Pecan trees can produce for well over hundred years.That's why it is important to start your pecan orchard with the best pecan trees available.

WE PRODUCE A WIDE VARIETY OF PECANS TO ORDER

PECAN PRO (PTY) LTDHEIKO W. MEIER

Tel · 017 821 0990 • Fax · 086 511 7047Cell · 083 282 5301 (Heiko) • E-mail · heiko@meier.co.za

Address · P O Box 22, Commondale 2385

ORDER NOW TO ENSURE THE BEST CULTIVAR SELECTION.

Wichita, Choctaw,