Further studies on the control of pre-emergence rot and crown rot of peanuts

Abstract

Experiments with fungicidal seed dressings on peanuts conducted during the seasons 1955 to 1959 are described. In laboratory tests there was a differential effect of fungicides on Rhizopus spp., Aspergillus niger and Penicillium spp. Organo-mercurials were very effective against Rhizopus spp. but not so effective against A. niger and Penicillium spp. Captan, thiram and chloranil were effective against A. niger and Penicillium spp. but not as consistently effective against Rhizopus spp. as the organo-mercurials. Field trials demonstrated that, under certain conditions, organo-mercurials increased the incidence of crown rot caused by A. niger. A number of fungicides controlled pre-emergence rot but the organo-mercurials and captan were the most consistent. A combination of these two fungicides gave best control over both pre-emergence rot and crown rot. Sowing rates could be profitably reduced to the recommended level, when reasonable control over crown rot can be expected.