Cotton seed treatment, granular and foliar nematicide combinations for reniform management in north Alabama, 2012

摘要

Seed treatment nematicides were evaluated in combination with Temik 15 G and Vydate CLV for the management of the reniform nematode in an infested cotton field on the Tennessee Valley Research and Education Center in Belle Mina, AL. The field was infested with the reniform nematode in 2007 and population densities have increased each year. The soil type was a Decatur silt loam (24% sand, 49% silt, 28% clay). Plots consisted of 2 rows, 7.6 m long, with 1 m row spacing and were arranged in a randomizedcomplete block design with five replications. Blocks were separated by a 7 m alley. The seed treatments were applied to the seed by Syngenta. Temik 15G (840 gai/ha) was applied at planting on 1 May in the seed furrow with chemical granular applicators attached to the planter. Vydate CLV was applied as a foliar spray at the 6 to 8 leaf stage using a CO2 charged backpack sprayer. All plots were irrigated and maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Plots were irrigated with a sprinkler system as needed. Seedling stand and vigor were determined at 30 days after planting (DAP) on 31 May. Nematode samples were collected including 10soil cores in a zigzag pattern across the plot and 150 cm3 of soil was extracted by gravity sieving and sucrose centrifugation. Plots were harvested on 10 Oct. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P < 0.10). Monthly average maximum temperatures from planting in April through harvest in October were 24.8, 29.7, 32.3, 34.7, 31.6, and 28.9°C with average minimum temperatures of 11.6, 17.2, 18.7, 22.5, 20.2, and 16.2°C, respectively. Rainfall accumulation for each month was 3.78, 7.24, 3.07, 12.19, 8.2, 8.0, and 12.6 cm. with a total of 55.1 cm. over the entire season. The rainfall was adequate in May but became limited through the remainder of the season. Temperatures did not reach the 100’s thus this season was more normal for heat units but dry.