Disease Management and Variable Planting Patterns in Peanut

Abstract

AbstractPeanut (Arachis hypogea L.) is typically sown in single or twin rows centered on 91-cm beds. A planter capable of sowing 8 peanut rows on a 182-cm bed was developed by USDA-ARS. This planting pattern optimizes plant spacing and may contribute to crop advantages. Management of soil borne diseases in peanut may be affected by planting patterns. Replicated field experiments were conducted in 2002, 2003, and 2004 at two locations each year near Dawson, Georgia to compare interactions of planting patterns and disease management programs. Three fungicide application regimes were factored over single row, twin row, and diamond planting patterns, for a total of 9 treatments. A block calendar schedule with 14-d intervals was compared with two weather advisory programs, including AU-Pnuts and an experimental version of AU-Pnuts using minimum daily soil temperature (MDST) as a guide for fungicide selection. The seeding rate of each planting pattern was 22 seed/m2. There were no planting pattern by fungicide program interactions. Twin row and diamond planting patterns were often superior in yield than single rows; however, diamond patterns did not yield better than twin rows. Incidence of peg, pod, and limb rot caused by Rhizoctonia solani and stem rot caused by Sclerotium rolfsii was not severe in any trial and was not affected by planting pattern. Despite low disease presence, the calendar program was consistently better for yield and overall disease control than the two advisory programs. Yield was similar for the three fungicide treatments in four of six experiments. Grade of twin row and diamond planted peanut was 0.7 points better than single row peanut over three years at one location. Net return based on crop value less fungicide program cost was more closely tied to yield than variable input costs for fungicide programs.