Southern Stem Rot Suppression On Peanut With The Insecticide Chlorpyrifos¹

Chlorpyrifos 15G(2.24 kg a.i./ha), PCNB 10G (11.2 kg a.i./ha), and PCNB 10G + chlorpyrifos 15G(11.2 + 2.24 kg a.i./ha) were compared for the suppression of southern stem rot caused by Sclerotium rolfsii Sacc. on peanut in on-farm trials on nine farms over three years (1982–1984). Chlorpyrifos, PCNB, and PCNB + chlorpyrifos significantly reduced loci counts all three years. PCNB + chlorpyrifos generally gave the best stem rot suppression and yield response, but there was little difference in disease loci counts between chlorpyrifos and PCNB. PCNB significantly increased yield over the control two years while chlorpyrifos increased yield only one year.