Chemical Control of Nesokia indica Gray in Sugarcane Fields of Khuzestan Province

Rodents are one of the most important pest of agricultural crops in the world. Rats cause loss directly yeild in sugarcane fields with cutting stalk of cane. In this study, fluctuations of population and chemical control of Nesokia indica Gray in sugarcane fields were investigated in Salman Farsi and Hakim Farabi agro-industries in Khuzestan/Iran. After harvesting of crop (early December) active nests were counted in three hectares and sampling was continued until ratooning operations weekly. Sampling in April until Julay was conducted with counting of damaged and dried tillers or observing of nest. Final sampling was at harvesting time based on pecentage of damaged stalks. Evaluation of chemical control was conducted as completely randomized design including: plots with and without bait with three replications. Baits of Kelerat (Brodifacom 0.005%) and Zinc phosphide 5% with grains of wheat were used in agro-industries Salman-Farsi and Hakim Farabi respectively. Baits were used two or three times after harvesting with interval one week. Number of active nests were counted and then percentage of nest reduction was calculated. All captured rats from sugarcane fields were Nesokia indica Gray. Investigation of fluctuations of pest population showed that peak of pest population was after harvesting time that it was over 100 active nests per hectare. The population reduced gratualy (rats leave the fields) after that with ratooning operations and then irrigation of fields. Rats return into sugarcane fields with stopping of irrigation at late of plant growth stage, and start their activity. Damaged stalks was over 20%. Kelerat bait (three times) reduced pest population over 90%, but using of zinc phosphide (two times) was not reduced significantly it. It is better that chemical control of pest counduct after harvesting of crop and before ratooning operations. also, It is recommend.