Germinated cereals as bait base for zinc phosphide and bromadiolone against rodent pests in paddy crop fields

Field trials were conducted to determine the efficacy of zinc phosphide (2%) and bromadiolone (0.005%) in germinated cereals (paddy, pearl millet and ragi) as a bait base against rodent pests in Samba season paddy crop fields during 2008, 2009 and 2010. The rodent population was estimated by live burrow count method and their depredation assessment by diagonal method in the chosen two developmental stages of the paddy crop, before and after poison bait treatment in the experimental and reference plots. The prepared baits were placed in two places i.e., at station (8 m interval) and active burrow entrances of experimental crop fields. The cost benefit ratio of the chosen rodenticides was also calculated. Both rodenticides significantly reduced population of rodents and their depredation. Of the two rodenticides used, the cost-benefit ratio favoured the zincphosphide (1:9 for paddy; 1:11 for pearl millet and 1:4 for ragi) when compared to bromadiolone (1:2 for paddy; 1:4 for pearl millet and 1:2 for ragi). Thus, it may be suggested that the zinc phosphide at 2% concentration prepared in anyone of these germinated cereals, which is economic may be recommended to farming community for adoption in order to reduce the tiller damage by rodent pests and consequently increase the yield.