NOVEL FUMIGATION METHOD FOR THE MANAGEMENT OF STORAGE PESTS OF RICER. VISVANATHAN, P. YASODHA, C.G.L. JUSTIN, S. SELVAM AND P. MASILAMANI
Owing to the advantage of on-site production and utilization of acetylene gas (C2H2), it would be more advantageous to use acetylene in place of CO2 and N2 in controlled atmosphere storage of food grains to inhibit respiration of insects. In this study, the effect of acetylene on the control of Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum and Callusobruchus maculatus in the storage of paddy grains (CV.TRY 3) was assessed. Paddy grains with known number of insects in a small container [conical flask (500 ml)] with airtight closure were filled with 100 percent acetylene gas. The storage pests were assessed for mortality at an interval of 24 h for 120 h. The containers opened after bioassay was left for progeny production up to 4 months. The pests and the duration of exposure and their interactions have shown significance with acetylene gas filling. For achieving 100% mortality of Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum and Callusobruchus maculatus, in the storage of paddy grains, the exposure time required were 111, 139, 153 and 139 h, respectively. The progeny of these storage pests were found insignificant with respect to long term storage period up to 4 months. The mean number of progeny production of adult and grub of these storage pests ranged from 1.7 to 7.7 and 0 to 1.7, respectively. In the scale-up (long term storage) studies conducted using the [bigger container plastic bins (25 kg)] up to 4 months, showed no survival of the adult / grubs and progenies production were seen. The storage for 30 days with acetylene gas ensured 100 per cent mortality of storage grain pests.