Locational dynamics of concentration and efficacy of phosphine against pulse beetle, Callosobruchus maculatus (Fab)

Phosphine is considered as an effective substitute to methyl bromide (MB), ozone depleting fumigant which was phased out honouring ‘Montreal Protocol’. Limited field studies are available on phosphine toxicity against storage insects of pulses under different climatic conditions in India. In the present study efficacy investigated laboratory cultured and populations Callosobruchus maculatus by organising fumigation trials 5 MT pulse stacks, each triplicate, varied conditions. The were conducted at three locations, Jaipur for Cicer arietinum (chickpea), Cuttack Vigna radiata (green gram) Mumbai Lathyrus aphaca (yellow pea) using conventional 56% Aluminium phosphide (AlP) tablets (2 tab/MT 3 tab/MT) application; gas derived from on-site generator with 77.5% granular (1.0 g 1.5 phosphine/m3) formulations two exposure periods (7 10-days) dosage including untreated control. concentration monitored daily until monitoring equipment. No emergence adults observed 60 days after treatment indicating 100% insect mortality both (laboratory field) all dosages. minimum controlling C. 300–500 ppm 7-days phosphine/m3 depending A significant variation during locations. Average concentration-time (Ct) product green gram higher than that chickpea yellowpea. loss found be significantly low yellowpea treated moderately hot humid climate.