Poster: Biology & Disease Mgmt: Chemical Control
Effect of fungicide timing and frequency on reducing foliar diseases and yield loss on runner and valencia type peanuts in Haiti
A. FULMER (1), T. Brenneman (1), R. Kemerait (1) (1) University of Georgia, U.S.A.
Peanut (Arachis hypogaea L.) yields in Haiti are often severely reduced by peanut rust (Puccinia arachidis) and late leaf spot (Cercosporidium personatum). Two trials were conducted in 2015 to evaluate the effect of 6 fungicide regimes on disease severity and yield for two market types. Both tests used a split plot design with 4 replications with variety as whole plot and fungicide as subplot. Runner (local landrace and Cv. Georgia-06G) and valencia (local landrace and Cv. N.M. Valencia A) market types were planted in northern and central Haiti, respectively. For runners, Muscle ADV (2.3 L/ha) was applied 2-6 times starting 30-60 days after planting (DAP) with 14-28 day intervals; valencias received 1-4 sprays starting 30-45 DAP with 14-28 day intervals. There were no interactions between variety and fungicide regime. At each location, disease severity was similar between varieties, but Georgia-06G and the local valencia yielded 2500 and 430 kg/ha more, respectively. For valencias, at least 2 sprays were required to reduce severity and increase yield; however, 3 or more sprays gave the highest yields. For runners, 3 and 4 sprays were required to reduce rust and leafspot, respectively, but 6 sprays had the least disease and the only statistically different yield. Compared to untreated plots, the best treatments increased yields by 68% for both market types. These results are a significant step toward developing management recommendations for growers in Haiti.