Temporal dynamics of phosphine fumigation against insect pests in wheat storage

Methyl bromide (MBr) fumigant has been phased out globally honouring ‘Montreal Protocol’. However, MBr is still used in India various commodities for controlling pests as well international trade requirements. Reports on phosphine efficacy under different ecological zones are scanty. In the present study fumigation trials were conducted warehouses 5 Metric-Tons of wheat stacks per replication a treatment testing against laboratory cultured and warehouse resident population Tribolium castaneum (Herbst), Sitophilus oryzae (Lin), Rhyzopertha dominica (Fab). The organized triplicate including untreated control at FCI two locations, Pithoragarh Uttrakhand New Delhi, with varying climates. conventional 56% Aluminium phosphide (AlP) tablet 2 3 tablet/MT, gas derived from on-site generator using 77.5% granular formulation 1.0 1.5 g phosphine/m3 was tested these test insects 7 10-days exposure periods each dosage. Phosphine concentration monitored every 24 h till end monitors. No emergence observed until 60 days after both all dosages indicating mortality life stages locations. g/m3 an effective alternative to methyl S. oryzae, R. T 250–27 °C humidity 38–45% period 7-days, terminal 500–600 ppm. Locational effect loss concentration. During fumigation, be inversely related grain moisture directly Ct values.