Effect of Phosphine and Methyl Bromide Fumigation of Different Life Stages of Peanut Bruchid, Caryedon serratus Olivier

To ensure seed quality, peanut seeds received for export by the Plant Quarantine Unit of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) were subjected to phosphine and methyl bromide fumigation. Effective control of eggs, larvae, and adults of Caryedon serratus Olivier was achieved with methyl bromide vacuum fumigation (16 g/m3 for 4 h exposure). Under normal atmospheric pressure (NAP), phosphine fumigation @ 0.5,1.0, and 2.0 g a.I./m3 for 24, and also with 0.25 g a.l. for 72 h gave effective control of eggs and larvae. Ph~phlne (1.0 g a.l./40 kg burlap bag) with bruchld Infested pods for 120 h resulted in 100% larval and 93% adult mortality. Both the fumigants did not impair the viability of peanut seeds. A dosage of 16 g/m3 of methyl bromide for 4 h under vacuum or 0.25 g a.l./m3 of phosphine for 72 h under NAP or placing 1.0 g a.l. of ph~phlne in dry pods stored in 40 kg burlap bag covered with polythene sheets for 120 h can satisfy the seed health requirements.