Control of Cabbage Maggot, 1981

‘Golden Acre’ cabbage was transplanted to the field on May 7, in Sunderland, MA. Twenty plants were transplanted to each plot. Ammonium nitrate at 135 lb/acre was applied on May 3. Treflan (6E) at 1.5 lb ai/acre was applied on May 1 and disced in for weed control. The soil type ws a fine sandy loam and had a pH of 7.0. There were two 25 ft rows per treatment, replicated 4 times in a randomized complete block design. Insecticide applications were based on 36 inch row spacing. All insecticidal treatments were applied with a 3 gal stainless steel backpack sprayer in 150 gal water/acre. Single applications of Dyfonate (4EC) at 1 lb ai/acre, Amaze (6E) at 0.5 lb ai/acre and 1 lb ai/acre were applied on May 14. The remaining treatments were applied on May 14, May 31, and Jun 12. Evaluations were made on Jun 29. Plant mortality due to cabbage maggot was calculated for each treatment. In addition, 5 roots/treatment/replicate were removed. This included a core of soil 3 inches wide X 5 inches deep. Roots and soil were rinsed through a screen to extract pupae and larvae. The total number of pupae plus larvae and cabbage maggot feeding tunnels were recorded. Due to high plant mortality in the control plots, insufficient data were available for analysis of pupal/larval and tunnel counts.