Evaluation of Fontelis for peanut disease control in southwest Alabama 2013

摘要

Peanut cultivar 'Georgia 06G' was planted at the Gulf Coast Research and Extension Center near Fairhope, AL on 17 May at a rate of five seed per ft of row in a field that had previously been cropped to peanut. Recommendations of the Alabama Cooperative Extension System for fertility and weed control were followed. The soil type was a Malbis fine sandy loam (OM <1%). 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. Foliar fungicides were applied at 14-day 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. Late leaf spot and rust were visually rated on 24 Sep using the Florida leaf spot scoring system (1 = no disease; 2 = very few lesions in upper canopy; 3 = few lesions in lower and upper canopy; 4 = some lesions with slight defoliation; 5 = lesions noticeable in upper canopy with some defoliation; 6 = lesionsnumerous with significant defoliation; 7 = lesions numerous with heavy defoliation; 8 = very numerous lesions on few remaining leaves with heavy defoliation; 9 = very few remaining leaves covered with lesions; 10 = completely dead plants) and the ICRISATrust rating scale (1 = no disease, 9 = plants severely affected, 80-100% leaves withering). Stem rot incidence was estimated on 9 Oct immediately after plot inversion by determining the number of disease loci (< 1 ft per locus) exhibiting symptoms of the disease or signs of the pathogen. Plots were harvested on 16 Oct and yields were reported at 8.15% moisture.