Climate change EAPR 2013 · 2017-07-07 · Potato Diseases and Pests in South Africa Jacquie van...
Transcript of Climate change EAPR 2013 · 2017-07-07 · Potato Diseases and Pests in South Africa Jacquie van...
Effect of Climate Change onEffect of Climate Change on Potato Diseases and Pests in South Africa
Jacquie van der Waals, Kerstin Krüger, Linus Franke, Anton Haverkort, Martin Steyn
EAPR 2013, Jerusalem
INTRODUCTION
Disease Pyramidy
PathogenPathogenGrower
Time
Disease
Host EnvironmentHost Environment
Late blightSoft rot and blacklegg
Myzus persicae
Root knot
(PVY and PLRV)
Root-knot nematodes
Early blight and brown spot
MATERIALS AND METHODSMETHODS
Disease development rulesDisease development rules
• For each organism a set of “rules” was drawn up• For each organism a set of rules was drawn up using literature to describe conditions for disease development or population growth: defined asdevelopment or population growth: defined as cumulative relative development rate (cRDR)
• Parameters used: min opt max temperature;• Parameters used: min, opt, max temperature; relative humidity
• Indication of change in disease pressure over• Indication of change in disease pressure over period 1961 - 2050
• High resolution climate models were used to• High resolution climate models were used to calculate daily weather data (maximum and minimum temperatures precipitation wind speedminimum temperatures, precipitation, wind speed and solar radiation) for the period 1961 – 2050
Hectares per Production RegionLimpopo
Loskop Valley
Dry winter≈ 2m tonnes produced annually on about
Mpumalanga
North West Gauteng
annually on about 60 000 ha
Eastern FS
KZNWet summer
Western FS
Northern Cape
South West FS
Eastern Cape
North Eastern Cape
Sandveld
Ceres
Southern Cape
Wet winterDry summer
Southern CapeSouth West Cape
B. Pieterse, 2009
RESULTS AND DISCUSSIONDISCUSSION
Shifts in planting timesShifts in planting times(Franke et al., 2013)
• Sandveld: Current peak plantings of August-September are likely to shift a month earlier to July-August; the autumn plantings remain unchanged
• EFS: October-November plantings will probably also move forward to September-October
• Limpopo: Main planting starts in May and continues through winter until July with the peakcontinues through winter until July, with the peak planting period in June. By 2050 planting likely to start earlier in April-Maystart earlier in April May
Hectares per Production RegionLimpopo
Loskop Valley
Dry winter
Mpumalanga
North West Gauteng
Eastern FS
KZNWet summer
Western FS
Northern Cape
South West FS
Eastern Cape
North Eastern Cape
Sandveld
Ceres
Southern Cape
Wet winterDry summer
Southern CapeSouth West Cape
B. Pieterse, 2009
Late BlightLate Blight
10˚C > Temp. < 26˚Cd RH 75% f t ti dand RH >75% for two consecutive days
(Beaumont 1947; Krause et al. 1975; MacKenzie 1981; Zwankhuizen & Zadoks 2002)
30 Late blight EFSb30
Late blight Sandvelda
15
20
25
ativ
e RD
R
15
20
25
ativ
e RD
R
5
10Cum
ula
5
10
Cum
ula
0
Planting month
0
Planting month
25
30
R
Late blight LimpopocCumulative relative development rates (cRDR) of late blight on potatoes for the periods
10
15
20
Cum
ulat
ive
RDR potatoes for the periods
1961-1970 (······), 2001-2010 (—–) and 2041 2050 ( ) in
0
5
C 2041-2050 (----) in (a) the Sandveld, (b) the Eastern Free State and(c) Limpopo growing regions in SA
Planting month(c) Limpopo growing regions in SA
Early Blight and Brown SpotEarly Blight and Brown Spot“I f ti d ”“Infection day” =
10˚C > Temp. < 35˚Cd RH 75%and RH >75%(Rotem 1974)
70Early blight and brown spot Sandvelda
70
Early blight and brown spot EFSb
40
50
60
tive
RDR
40
50
60
tive
RDR
10
20
30
Cum
ula
0
10
20
30
Cum
ulat
0
Planting month
0
Planting month
60
70
R
Early blight & brown spot LimpopocCumulative relative development rates (cRDR) of early blight and brown spot on potatoes for the
20
30
40
50
Cum
ulat
ive
RDR brown spot on potatoes for the
periods 1961-1970 (······), 2001 2010 ( ) and
0
10
20C 2001-2010 (—–) and 2041-2050 (----) in (a) the Sandveld, (b) the Eastern Free State and
Planting month(b) the Eastern Free State and(c) Limpopo growing regions in SA
Soft Rot and BlacklegSoft Rot and BlacklegRDR 1 if A d il t 26˚CRDR = 1 if Ave daily temp = 26˚C
RDR = if Ave daily temp < 4˚C or > 37˚CIntermediate RDR values obtained through linearIntermediate RDR values obtained through linear
interpolation of values from 4-37˚CAir temp averages used as indication of prevalent soil
temps: (Tsoil = (Tmax + Tmin)/2)Soils are irrigated
(Duarte et al 2004; du Raan In Prep )(Duarte et al. 2004; du Raan In Prep.)
90
Pcb Sandvelda90
Pcb EFSb
50
60
70
80
ive
RDR
50
60
70
80
ve R
DR
10
20
30
40
Cum
ulat
i
10
20
30
40
Cum
ulat
i
0
Planting month
0
Planting month
80
90
Pcb Limpopoc Cumulative relative development rates (cRDR) of soft rot and blackleg on potatoes for the periods
40
50
60
70
mul
ativ
e RD
R
blackleg on potatoes for the periods 1961-1970 (······), 2001-2010 (—–) and 2041 2050 ( ) in
0
10
20
30
Cum 2041-2050 (----) in
(a) the Sandveld, (b) the Eastern Free State and(c) Limpopo growing regions in SA
Planting month
(c) Limpopo growing regions in SA
Root Knot NematodesRoot Knot NematodesRDR t d il t f 26 °C 1/25 0 04RDR at ave daily temp of 26 °C=1/25=0.04RDR = 0 if ave daily temp < 9.5˚C or > 34˚C
Intermediate RDR values obtained through linearIntermediate RDR values obtained through linear interpolation of values from 9.5-34˚C
Air temp averages used as indication of prevalent soil temps: (Tsoil = (Tmax + Tmin)/2)
Soils are irrigated(Vrain et al 1978; Ploeg & Maris 1999)(Vrain et al. 1978; Ploeg & Maris 1999)
3.5
RKN Sandvelda3.5
RKN EFSb
2
2.5
3
tive
RDR
2
2.5
3
tive
RDR
0.5
1
1.5
Cum
ulat
0.5
1
1.5
Cum
ula
0
Planting month
0
Planting month
3
3.5
RKN LimpopocCumulative relative development rates (cRDR) of root-knot nematodes for the periods
1.5
2
2.5
mul
ativ
e RD
R nematodes for the periods 1961-1970 (······), 2001-2010 (—–) and 2041 2050 ( ) in
0
0.5
1Cu
2041-2050 (----) in (a) the Sandveld, (b) the Eastern Free State and(c) Limpopo growing regions in SA
Planting month
(c) Limpopo growing regions in SA
Aphids as Vectors of PVYAphids as Vectors of PVYO ti l RDR i 1/1 95 0 51 t 26 7°COptimal RDR is 1/1.95=0.51 at 26.7°C.
Linear interpolation used to determine doubling timeRDR = 0 if daily min temp < 6 5°C or max > 37 3°CRDR 0 if daily min temp < 6.5 C or max > 37.3 C
(Bale et al., 2002; Davis et al. 2006)
45
Aphids Sandvelda45
Aphids EFSb
25
30
35
40
45
ve R
DR
25
30
35
40
ve R
DR
5
10
15
20
25
Cum
ulat
iv
5
10
15
20
Cum
ulat
iv
0
Planting month
0
5
Planting month
40
45Aphids Limpopoc Cumulative relative development
rates (cRDR) of aphids on potatoes for the periods
20
25
30
35
mul
ativ
e RD
R
for the periods 1961-1970 (······), 2001-2010 (—–) and 2041 2050 ( ) in
0
5
10
15
Cum 2041-2050 (----) in
(a) the Sandveld, (b) the Eastern Free State and(c) Limpopo growing regions in SA
Planting month
(c) Limpopo growing regions in SA
CONCLUSIONS
•Predictions can be made on how frequentlyq yparticular weather patterns will occur until20502050
Shift i l ti ti i ht ll•Shifts in planting times might allow escapefrom pathogens or pests
•Changes in climate are gradual – enoughg g gtime to alter management practices
• Published as: van der Waals et al. (2013) Potato Research 56:67-84
ACKNOWLEDGEMENTSACKNOWLEDGEMENTS
Funding:N h l d Mi i f E A i l• Netherlands Ministry of Economy, Agriculture and InnovationP t t S th Af i• Potatoes South Africa
• THRIP
Second announcement of the
2ND INTERNATIONAL POWDERY SCAB WORKSHOP
29 July – 1 August 2014
S th Af i (Kl i K ib Li P i )South Africa (Klein Kariba, Limpopo Province)
For more information email
jacquie vdwaals@up ac [email protected]