Prof. Teofilo VameraliUniversity of Padova - Italy

Effects of seed-applied fungicides on root growth of wheat under controlled conditions and in open fields

Wheat in EuropeKEY POINTS:

• 225 Mt of wheat grains;• Important actor in world production (~30%);• Fast per-hectare yield increase (~4 t ha-1);• Amelioration of agricultural practices;• Further improvements are possible.

Weaknesses: fungal diseases and mycotoxin control, weedmanagement, nitrogen fertilisation with restrictiveenvironmental regulations (Nitrate Directive).

2013

Countries delivering the 5 highest yieldsAverage 1983 - 2013100k

Ok

Hg/

HaHg/

Ha

50k

40k

30k

20k

Fungal diseases in small-grain cerealsSeed-borne pathogens:• Fusarium spp.• Michrodochium nivale (seedling blight);• Ustilago tritici (loose smut);• Tilletia caries (common bunt / stinking smut).

Soil pathogens:• Septoria tritici (septoria leaf blotch);• Stagonospora/Septoria nodorum;• Rhizoctonia cerealis (sharp eyespot);• Fusarium spp.• Etc.

Many of these can seriously compromise plant establishment (particularly roots), crop success and yield.

Mandatory strategies:1. Prevention against fungal pathogens2. Promotion of early plant growth

Fusarium foot rots

Rhizoctonia

Research aims

• To study its growth (roots) enhancement power vs. older fungicides and untreated controls;

• To identify targeted root parameters;

• To verify whether any implication on yield performance or quality exists;

• To ascertain whether effects are stable across years and soil types.

Framework: a new SDHI fungicide sedaxane available for seed treatments

CONTEXT:Italian environment (controlled conditions and open fields). Common and durum winter wheat.

VIBRANCE GOLD (commercial formulation)Pathogen Efficacy Pathogen Efficacy

Fusarium spp. Septoria nodorum

Macrodochium nivale Puccinia recondita

Pyrenophora graminea Erysiphe graminis

Ustilago nuda Rhizoctonia spp.

Cochliobolus sativus Typhula incarnata

Tilletia caries Gaeumannomyces graminis

Excellent Good

* *

Methods• 2-year field trial: 2012/13 & 2013/14

Legnaro - Experimental farm of the Univ. of Padova

Foggia - Syngenta experimental farm

• 1st year - common wheat: cv. ILLICO

• 2nd year - durum wheat: - cv. SARAGOLLA (Foggia)- cv. ISILDUR (Legnaro)

Legnaro - Padova

Foggia

lysim

eter

s

open field plots

ROOTENHANCEMENT

Treatments under studySeed-applied fungicides:

• VIBRANCE GOLD (fludioxonil + difenoconazole + sedaxane ): 200 mL dt-1

5 g 5 g 10 g

• CELEST EXTRA (fludioxinil + difenoconazole): 200 mL dt-1

5 g 5 g

• Untreated controls

5 m

100-m2 plots20 m

Rhizoboxes Lysimeters Open field

Rhizoboxes with various soilsEffects of VIBRANCE:

• Faster root deepening;

• Greater root length and area;

• Increased number of root tips and forks.

OrganicSilty-loam

Sandy

Clay

Control CELEST VIBRANCE

45 c

m

SANDY SOIL: 43 days of cultivation

Analysis with WINRHIZO TM

Rooting power

% increase vs. controls for significant root parameters

• Root surface area is the most affected parameter;

• Generally: VIBRANCE = CELEST (P = 0.05);

• No. root tips/forks: VIBRANCE > CELEST;

• Similar response in sterilised soil (protection and rooting power are separate mechanisms).

Sandy soil

LENGTH 54% 42% 54% 47%AREA (Horiz. Proj.) 51% 39% 52% 52% 48% 40%CONTACT SURFACE 51% 39% 52% 43% 48% 40%DIAMETERVOLUME 49% 45% 56% 54%No. TIPS 59% 80% 46% 54%No. FORKS 59% 65%

SILTY-LOAM CLAYTYPES OF SOIL

CELEST VIBRANCE CELEST VIBRANCE CELEST VIBRANCE CELEST VIBRANCESANDY ORGANICPARAMETERS

Positive effects, as a trend (P>0.05)

+29% +26%

Lysimeters with various soils

45 c

m

December 5, 2012 (40 DAS)

• Starter effect of VIBRANCE, with faster soil cover;

• Improved seed emergence rates:88% vs. 62% of controls.

SandyClay

Silty-loam Organic

Sowing density: 385/m2

+42%

Control VIBRANCE

ControlVIBRANCE Control VIBRANCE

ControlVIBRANCE Control VIBRANCE

Root responses in various soils

April 5, 2013 (162 DAS)

SILTY-LOAM

45 c

m

Silty-loam

Sandy

SANDY

June 5, 2013 (harvest)

+95%

Control VIBRANCE

ControlVIBRANCE+15%

Control

VIBRANCE

Control

VIBRANCE

• Improved Root Length Density in more crucial conditions;

• Clay and organic soils: VIBRANCE ≅ Control

COMMON WHEAT at Legnaro (2012/13)

Auger sampling and image analysis

Silty-loam soil

December 18, 2012 (54 DAS) April 11, 2013 (168 DAS)

+13%

Control

VIBRANCE

CELEST

+9%

Control

VIBRANCE

CELEST

Harvest: mean RLD 0 - 150 cm

Control VIBRANCECELEST

Improved Root Length Density by VIBRANCE(early stages: above ploughing depth; later: below)

Attenuated differences at harvest

DURUM WHEAT at Legnaro (2013/14)January 15, 2014

VIBRANCE +14% in RLD

• Root length enhancement by VIBRANCE and CELESTat both tillering and spiking stages;

• VIBRANCE: better increases in root area(Surface area = projected area × 3.14 ).

April 30, 2014 (spiking)

Silty-loam soil

+6%

Control VIBRANCECELEST

+5%

+8%

Control

VIBRANCE

CELEST

DURUM WHEAT at Foggia (2013/14)

• Contrasting results across soil profile, with a root enhancement effect of VIBRANCE in top and deep soil;

• Root shifting in deeper layers;

• Unexpected great decrease of CELEST (-19%) due to anomalous calcareous subsoil.

April 15, 2014 (spiking)

Length →

Area →

January 10, 2014

Sandy-clay soil

+4%

+3.4%

Control

VIBRANCE

CELEST

ControlVIBRANCE

CELEST

Effects on grain: YIELD

• Substantial stable yields among treatments;

• Yield increases induced by VIBRANCEbetter observable in conditions of lower fertility (e.g., Foggia).

COMMON WHEAT (2013) July 2, 2013

DURUM WHEAT (2014)

(d.w

.)

+0,2%

Control VIBRANCECELEST

+0,2%

+0,8% +0,8% +15% +25%

Control VIBRANCECELEST Control VIBRANCECELEST

Effects on grain: QUALITY and N uptake

• Small variations among treatments, with more proteins in treated plants of durum wheat;• Interesting greater N uptake in whole plants.

LEGNARO

N Grain + N straw

N Grain + N straw

Control VIBRANCECELEST

Control VIBRANCECELEST

+15 kg

+24 kg

Control VIBRANCECELEST

Control VIBRANCECELEST

Phenolic acids at harvest

• Constantly greater concentration in VIBRANCE-treated plants; some of these acids are active against fungal pathogens;

• Similar trend in the grains (concentration ∼75% lower): nutraceutical effect.

Abundant antioxidant compounds in wheat

HPLC

+5.9% +6.5% +3.4%+7.0%

0

100

200

300

400

500

600

Unt

reat

ed

Vibr

ance

Unt

reat

ed

Vibr

ance

Unt

reat

ed

Vibr

ance

Unt

reat

ed

Vibr

ance

SANDY CLAY SILTY-LOAM

ORGANIC

mg/

kg d

.w.

STRAW

T-Ferulic

P-Coumaric

Syringic

Caffeic

Vanillic

+14%

+10.5% +11.6+4.5%

0

20

40

60

80

100

120

Cont

rol

Vibr

ance

Cont

rol

Vibr

ance

Cont

rol

Vibr

ance

Cont

rol

Vibr

ance

SANDY CLAY SILTY-LOAM

ORGANIC

mg/

kg d

.w.

GRAINS

T-Ferulic

P-Coumaric

Syringic

Caffeic

Vanillic

Conclusive remarks

• Both tested seed-applied fungicides have marked power rooting, but VIBRANCE shows more stable effects;

• All improved root parameters (SURFACE, LENGTH, No. TIPS) can be related to efficient nutrient and water uptake, particularly in conditions of stress.

VIBRANCE vs. Plants

VIBRANCE vs. Farmers/Environment• Starter effect of VIBRANCE can be efficiently exploited for safe and quick plant establishment

during the most delicate early phases;• Quantitative/qualitative yield advantages cannot always be expected with this larger root

apparatus, but a poor root system is always responsible for yield losses;• With VIBRANCE, reduced N leaching, improved NUE and reduction of N fertilisers can help the

environment and save resources.

A new concept of “plant wellbeing”• Greater abundance of phenolic acids in green parts and in grains from seeds receiving VIBRANCE.

• Prof. Teofilo Vamerali• Prof. Giuliano Mosca• Dr. Valentina Zanella

• Dr. Giuseppe Barion

• Dr. Davide Piragnolo

• Dr. Marianna Bandiera

• Dr. Cristian dal Cortivo

• Mr. Adriano Massignan

Thank you for your attention

The Root Lab team at the University of Padova