Fenoxycarb, Pymetrozine (C G A-215944), and Fenpropathrin/Acephate: Rotations for Silverleaf Whitefly Control in Upland Cotton in Central America

Abstract

Trials (0.01 ac plots) with fenoxycarb ( Fenoxycarb 40 W P, 0.0621b. ai /ac), pymetrozine (CGA 215944, Fulfill™ 50 W P, 0.094 lb. ai/ac), pymetrozine /fenoxycarb, (SterlingTM ), and fenpropathrin (DanitolTM 2.4 E C, 0.20 lb. or 0.10 lb. ai/ac) /acephate (OrtheneTM 90 S, 0.5 or 0.25 lb. ai /ac) were made against silverleaf whitefly, Bemisiq grgentifolii Bellows and Perring, at UA, Maricopa Agric. Ctr. Six applications (plus adjuvant Kinetic) were applied on 9 treatments. Ten treatments (embedded control included) were in a double tier complete random block design and there was I adjacent, 1.5 ac control block (treatment 11). Eggs and large nymphs were sampled weekly post application to determine efficacy; reported as % reduction from block control. Rotation schemes were: 1) 3 pymetrozine /fenoxycarb, then 3 fenpropathrin/acephate applications, 2) 3 pymetrozine 2 /3rate /fenoxycarb full rate, then 3 fenpropathrin /acephate applications, 3) fenoxycarb 6 applications, 4) pymetrozine 6 applications, 5) 3 fenpropathrin /acephate, then 3 pymetrozine /fenoxycarb applications, 6) 3 fenpropathrin /acephate, then 3 pymetrozine /fenoxycarb, 7) fenpropathrin /acephate at full, l/2, full, then 3-1/2 rate applications, 8) 2 pymetrozine /fenoxycarb, 2 fenpropathrin /acephate, 1 pymetrozine /fenoxycarb, and 1 last fenpropathrin /acephate application, 9) 2 fenpropathrin /acephate, 2 pymetrozine /fenoxycarb, 1fenpropathrin/acephate, and 1 last pymetrozine /fenoxycarb application, 10) embedded control, and 11) block control. Egg % reductions for season means ranged from 93-99% for combinations and rotations of them. Last % season analyses showed reductions from 95-99 %. Pymetrozine had a 98% reduction andfenpropathrin /acephate had 98 % egg reduction. Nymphal reduction for season means ranged from 80-95% for combinations and rotations of them. Last % season analyses, showed % reductions from 91-98 %. Pymetrozine had 92% reduction and fenpropathrin /acephate had 92% reduction of nymphs (season). These studies showed that pymetrozine, pymetrozine /fenoxycarb, fenpropathrin/acephate combinations and rotations provided excellent control of silverleaf whitefly immatures.