Sugarbeet Root Maggot Control, 1991

Abstract

Abstract Sugarbeets were planted by the grower on 24 Apr near Rupert, ID. The soil type was Portneuf silt loam. Twelve treatments and an untreated check were replicated 6 times in a randomized complete block design. Individual plots were 6 rows (22 inch row spacing) by 30 ft. Alleys were cut between plots to give 25 ft of row/plot. Tenax, Lorsban, Counter, and Temik were applied in a 4-5 inch band (BAP) behind the press wheel and chain incorporated at planting. Lorsban and Furadan were applied as a post-emergence spray (PES) on 22 May at early fly emergence in a 3-4 inch band sprayed over the top of the beet row using 50 gal water/acre (30 psi, hollow cone single nozzle). Temik, Lorsban, and Counter were applied post emergence (PE) in a 4 -5 inch band over the row and chain incorporated at peak fly on 3 Jun. On 24 Jul, 5 adjacent beets were dug from the middle of rows 2 and 5 of the 6 row plots to give 10 beets/plot for rating for root maggot damage. The beets were washed and rated using the following rating schemes: 5 Point: 0 = no scars; 1 = 1-4 small scars of pinhead size; 2 = 5-10 small scars to 3 large scars; 3 = more than 3 large scars; 4 = 50 to 75% root area blackened by scars; 5 = more than 75% of root area damaged; and 7 Point: 0 = no damage; 1 = 1 to 4 small scars of pinhead size; 2 = 5 to 10 small scars; 3 = more than 3 large scars; 4 = 4 large scars to 25% root surface covered with scars; 5 = 25 to 50% root surface covered with scars; 6 = 50 to 75% root area blackened by scars; 7 = more than 75% root surface blackened, dying beet. Root maggot damage is reported for both the 5 point and 7 point rating systems in the table as the sum for 10 beets/plot. Yield data were taken by digging and weighing the untared beets from the middle 2 rows of each plot and is reported in the table as the yield/50 row ft. Beets were harvested for yield on 2 Oct. Data were analyzed using ANOVA and Newman- Keuls.