Cabbage Maggot Control on Chinese Cabbage, Japanese Radish, and Turnip, 1979

The tests were conducted at Yakima, WA, in Ritzville sandy loam soil (coarse, silty, mesic, Calciorfhidic Haploxerolls) with a pH of 6.2 and containing 1.6% organic matter. Seeds were planted on Aug 6 in plots consisting of 2 rows (55.9 cm apart x 6.1 m long). Plots were separated by 0.91 m alleys. Interplant spacing of Japanese radish and turnips was 10.2-15.2 cm and that of Chinese cabbage was 30.5-40.6 cm. Treatments applied to the different crops consisted of 3 rates of Lorsban plus the control and were replicated 4 times in a randomized complete block design. The at-plant granular treatments were applied and incorporated by use of the “bow wave” method whereby the opening and covering shoes of the seeder are used to distribute and incorporate the insecticide. These were followed by a 30-day postplanting (= 30-day preharvest) application to the soil surface of a band spray of the EC formulation at the same rates as the granules. The pesticides were applied in 13.25 litre water/304.8 m linear ft of row through TeeJet 80015E even-spray flat fan nozzles operated at 3.16 kg/cm2 by air pressure. Both treatment methods resulted in 7.6-10.2 cm wide bands of insecticide over the row. With turnips only, an additional test was conducted in which only at-planting granular treatments were applied. At harvest, 15 plants selected at random from each plot were washed and examined for determination of yield, number of roots injured, and degree of Injury to the roots based on an injury rating.