The response of cotton to seed and in-furrow treatments for nematode control in Suffolk, Virginia, 2006

摘要

Soil at the field site was Kenansville loamy fine sand and was prepared for planting by ripping and strip-tilling rows in wheat stubble. Plots were planted on 25 Apr. Treatments were main plots of four, 30-ft long rows spaced 36 in. apart andsubplots were two rows planted to ST 4575 BG/RR (susceptible to southern root-knot) and ST 5599 BR (partially resistant to southern root-knot). A split-plot design was used with replications in four randomized complete blocks. Seed used in eachtreatment were from the same lot of each variety. The base treatment of fungicide on ST 4575 BG/RR was Baytan/Thiram/Allegiance and ST 5599 BR was treated with Apron XL/Maxim/NuFlow. Personnel with Syngenta Crop Protection applied Avicta Complete Pak. The in-furrow treatment with KC791230 5 lb/A was applied at planting. Treatments with Temik 15G were applied in-furrow at planting with and without a side dress application during cultivation on 10 Jul.Foliar sprays of Orthene 97 at 6 oz/A were applied toall plots on 12 and 31 May for thrips control. Thereafter, standard practices were followed for cotton production in Virginia. Soil samples for determining nematode populations were collected on 26 Jul, and a composite sample of replications was preparedfor each treatment and variety. A soil elutriator and sugar flotation method were used to process samples. All plots were harvested with a two-row, spindle picker on 21 Oct. Rainfall in Jun, Sep and Oct was 5.75, 4.64 and 4.62 in. above normal, and in May, Jul, and Aug was 0.96, 2.21, and 3.21 in. belownormal, respectively. Rainfall during the period totaled 36.4 in., which was 8.6 in. above normal. Minimum air temperatures averaged near normal ( +- 1deg F) in Jun, Jul and Sep, 2deg F above normal in Oct, 3deg F above normal in Aug, and 2deg F below normalin May. Maximum air temperatures were near normal ( +- 1deg F) in May, Jun, Jul, and Oct, 2deg F below normal in Sep, and 4deg F above normal in Aug according to records from a NOAA station 4 miles northwest of the test site.