Control of Armyworm on Bell Pepper, 1991

Abstract

Peppers were transplanted on 10 Sep 25 cm apart in 2 rows 12.5 cm to either side of the centerline in plastic-mulched, raised beds on sand soil with seep irrigation. Treatments were replicated 4 times in a randomized complete block design with each treatment plot consisting of 6 m of double-row bed. One week prior to treatment, a single neonate BAW was placed on the center 12 plants in each plot. Treatments were applied with a drop nozzle sprayer using a diaphragm pump driven by a dedicated engine and pulled with an all terracum vehicle. Albuz yellow tip ceramic nozzles delivering 0.45 gpm at the operation pressure of 100 psi were used on a single-row boom. Sprayer configuration was adjusted for adequate coverage, beginning on 10 Oct with 2 over-the-row and 2 side nozzles for the first through fourth application, and adding 2 additional side nozzles with a single overhead for the remaining 3 applications. Delivery rates were 30 gal/acre for the first application, 50 gal/acre for the second through the fourth, and 63 gal/acre for the rest. The surfactant APSA-80 (@0.03%) was added to all 16 treatments and the water control. The NPV formulation, SX-61991, was applied by backpack sprayer because of windy conditions on the second and third application dates, to reduce the risk of cross-plot contamination. Five randomly selected plants from each plot were examined for armyworms 2 days post-treatment. The top 5 leaves of 2 or more growing tips of each of the same plants were evaluated for worm damage. Twenty plants near the center of each plot were randomly selected on 20 Nov and 11 Dec for harvest and evaluation. Pressure was intense during most of the trial with SAW the predominant species. The most significant differences were between chemical and biological treatments. Differences between Bt treatments were less evident, although dose responses were generally consistent for all products.