INTEGRATING VARIETAL RESISTANCE WITH PHOSPHONATE … · Agri-Fos 400 Mono-di potassium 46% Fosphite...
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INTEGRATING VARIETAL RESISTANCE WITH PHOSPHONATE FUNGICIDE IN MANAGEMENT OF FOLIAR LATE BLIGHT IN POTATO Elly Ouma Atieno , Elmar Schulte-Geldermann, Rama Narla, J.W Kimenju, Bruce Ochieng Obura Background Late blight is still limiting factor to potato production in developing countries. Chemical control is becoming more difficult due to the new and more aggressive strains, high costs of fungicides and resulting health in developing countries. Figure 2. Caption in Calibri, 36 points, bold. Figure 1. Farmer field affected by late blight Lab Logo Figure 2. Mean rAudpc Figure 3. AUDPC with different levels of phosphonates and different level of variety resistance Discussion Ridomil + Mancozeb had slightly better control of LB especially towards maturity compared to phosphonates. Yields similar with more resistant and slightly lower with more susceptible varieties Combination phosphonates +resist. var. Agrifos 400 good alternative LB control, having similar yields at a lower cost compared to chemical control Conclusion and recommendation Given the potential economic, health and environmental benefits gained by using available Phosphonate compounds farmers in developing countries should be encouraged to include Phosphonates in their late blight management strategies. Research should be done to optimize the usage on specific host genotypes, especially related to rates and timing of applications. References ANDREU, A.B., M.G. GUEVARA, E.A. WOLSKI, G.R. DALEO, D. O. CALDIZ, 2006: Enhancement of natural disease resistance in potatoes by chemicals. Pest Manag. Sci. 62, 162-170.. LOBATO, M. C., OLIVIERI, F. P., ALTAMIRANDA, E. A.G., WOLSKI, E. A., DALEO, G. R., CALDIZ, D. O., AND ANDREU, A. B. 2008. Phosphite compounds reduce disease severity in potato seed tubers and foliage. Eur. J. Plant Pathol. 122: 349-358. . Why Phosphonate Fungicides Phosphonates provides an alternative that appears appropriate for developing countries primarily because it represents a low risk to human health and environment. Materials and methods Field trials were conducted in five sites of different altitudes; Kabete, Koibatek, Kisima, Njambini, and Limuru. Potato varieties of different level of resistance were used. Treatments were laid out in a split plot design replicated 4 times. Fungicide Active ingredient Agri-Fos 400 Mono-di potassium 46% Fosphite 53sl Mono-di potassium 53% Dithane M-45 Mancozeb 800g/Kg Ridomil Mefenoxam 40g/kg +Mancozeb 640 g / kg Figure 4. Yields (t*ha -1 ) with different levels of phosphonates and different levels of variety resistance Results Figure 5. Potato field sprayed with phosphonate fungicide
Transcript of INTEGRATING VARIETAL RESISTANCE WITH PHOSPHONATE … · Agri-Fos 400 Mono-di potassium 46% Fosphite...
INTEGRATING VARIETAL RESISTANCE WITH PHOSPHONATE FUNGICIDE IN MANAGEMENT OF FOLIAR LATE BLIGHT IN POTATO
Elly Ouma Atieno, Elmar Schulte-Geldermann, Rama Narla, J.W Kimenju, Bruce Ochieng Obura
BackgroundLate blight is still limiting factor to potato production in developing countries. Chemical control is becoming more difficult due to the new and more aggressive strains, high costs of fungicides and resulting health in developing countries.
Figure 2. Caption in Calibri, 36 points, bold.
Figure 1. Farmer field affected by late blight
Lab Logo
Figure 2. Mean rAudpc
Figure 3. AUDPC with different levels of phosphonates and different level of variety resistance
DiscussionRidomil + Mancozeb had slightly better control of LB especially towards maturity compared to phosphonates. Yields similar with more resistant and slightly lower with more susceptible varietiesCombination phosphonates +resist. var. Agrifos 400 good alternative LB control, having similar yields at a lower cost compared to chemical control
Conclusion and recommendationGiven the potential economic, health and environmental benefits gained by using available Phosphonate compounds farmers in developing countries should be encouraged to include Phosphonates in their late blight management strategies.Research should be done to optimize the usage on specific host genotypes, especially related to rates and timing of applications.
References ANDREU, A.B., M.G. GUEVARA, E.A. WOLSKI, G.R. DALEO, D.
O. CALDIZ, 2006: Enhancement of natural disease resistance in potatoes by chemicals. Pest Manag. Sci. 62, 162-170..
LOBATO, M. C., OLIVIERI, F. P., ALTAMIRANDA, E. A.G., WOLSKI, E. A., DALEO, G. R., CALDIZ, D. O., AND ANDREU, A. B. 2008. Phosphite compounds reduce disease severity in potato seed tubers and foliage. Eur. J. Plant Pathol. 122: 349-358.
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Why Phosphonate FungicidesPhosphonates provides an alternative that appears appropriate for developing countries primarily because it represents a low risk to human health and environment.
Materials and methodsField trials were conducted in five sites of different altitudes; Kabete, Koibatek, Kisima, Njambini, and Limuru.Potato varieties of different level of resistance were used. Treatments were laid out in a split plot design replicated 4 times.
Fungicide Active ingredient
Agri-Fos 400 Mono-di potassium 46%Fosphite 53sl Mono-di potassium 53%Dithane M-45 Mancozeb 800g/KgRidomil Mefenoxam 40g/kg
+Mancozeb 640 g / kgFigure 4. Yields (t*ha-1) with different levels of phosphonates and different levels of variety resistance
Results
Figure 5. Potato field sprayed with phosphonate fungicide
