Phytotoxicity of Lorsban to Direct-Seeded Cabbage, 1984

Grower concerns for reduced and uneven stands of Lorsban-treated cabbage in the spring of 1984 prompted a test to determine the potential for phytotoxicity of Lorsban to direct-seeded cabbage. The plots were seeded on 21 Sep using a John Deere Flexiplanter unit mounted on a tractor. The soil was wet and planting conditions were marginal. These planting conditions were similar to the conditions in the spring when the uneven stands had occurred. Plots consisted of 30-ft single-row treatments replicated 3 times in a randomized complete block design. The entire plot was planted twice, one plot being irrigated with 1 inch of water on 24 Sep and the other left unirrigated. Treatments in each plot consisted of 2 series of 5 rates of Lorsban 4E, plus an untreated check. Lorsban 4E for 1 of the series of treatments (Lorsban I) was donated by a grower who had noted uneven stands. Lorsban 4E for the other series (Lorsban II) was supplied to us by Dow Chemical Corp. The Lorsban treatments were applied in 30 gal of water/acre as a 2-3 inch band over the furrow after planting. A CO2 power sprayer mounted on wheels with an attached speedometer was used to apply the spray. All water and insecticide calculations were made on a 36-inch row width basis. Stand counts were taken and plant heights were measured from the center 20 ft of each treatment on Oct 10, Fifteen plants/treatment were measured. Heights given are in inches.