Unharvested Peanut Pods as a Potential Source of Inoculum of Soilborne Plant Pathogens. D. K. Bell, Department of Plant Pathology, University of Georgia, Coastal Plain Experiment Station, Tifton 31793. Donald R. Sumner, Department of Plant Pathology, University of Georgia, Coastal Plain Experiment Station, Tifton 31793. Plant Dis. 68:1039-1042. Accepted for publication 20 August 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-1039.

Peanut pods or foliage (leaves and stems) plus root debris collected 22 wk after harvest were placed in layers at depths of 0–5, 5–10, and 10–15 cm in pots of heat-treated soil and planted to corn and soybean. The root-mesocotyl disease index (RMDI) on corn and the root-hypocotyl disease index (RHDI) on soybean were higher when plants were grown in soil amended with pods (SAP) than in soil amended with foliage plus root debris (SAFR) and the indices increased with depth of placement of pods. Root growth and plant height of corn and soybean and green foliage weight of soybean were less when plants were grown in SAP than in SAFR. Rhizoctonia solani anastomosis group (AG) 4 and Pythium spp. were isolated primarily from corn roots and soybean hypocotyls grown in SAP. Fusarium spp. were isolated from corn roots and soybean hypocotyls grown in both SAP and SAFR. Emergence of peanut, soybean, snap bean, blue lupine, and sorghum but not corn was reduced by R. solani AG-4 isolates recovered from sound peanut seed in pods attached to plants at harvest. The AG-4 isolates caused high RHDI or RMDI on all crops except corn, and AG-2 type 2 isolates recovered from sound peanut seed in pods attached to plants at harvest caused moderate to severe RHDI or RMDI on all crops except peanut. The RHDI or RMDI caused by AG-2 type 1 isolates did not differ from those in the control.