Comparison of chlorothalonil fungicides for peanut disease control in southwest Alabama, 2007

摘要

Peanut cultivar ‘GA 03L’ was planted at the Gulf Coast Research and Extension Center near Fairhope, AL on 23 May at a rate of five seed per ft of row in a field without a prior history of peanut production. The soil type was a Malbis fine sandy loam(OM <=1%). Recommendations of the Alabama Cooperative Extension System for fertility and weed control were followed. Plots, which consisted of four 30 ft rows on 38 in. centers, were arranged in a randomized complete block with six replications. Plots were not irrigated. Fungicides were applied at 14-d intervals as a full canopy spray using a four-row ATV-mounted CO2 sprayer with three TX8 nozzles per row calibrated to deliver 15 gal/A. Early and late leaf spot as well as rust were visually rated on 3Oct using the Florida leaf spot scoring system and the ICRISAT rust rating scale. Counts of stem rot (SR) loci were made on 9 Oct immediately after plot inversion (1 locus is defined as <= 1 ft of consecutive symptoms and signs of the disease). Plots were harvested on 12 Oct and yields were reported at 10.0% moisture.