RESEARCH ARTICLE Critical Timings of Rodenticide Bait Application for Controlling Rodents in Sugarcane Crop Grown in Situations Like Punjab, India Neena Singla • Bhupinder Kaur Babbar Received: 29 June 2011 / Accepted: 22 December 2011 / Published online: 11 January 2012 Ó Society for Sugar Research & Promotion 2012 Abstract Farmer field trials on determination of critical timings of rodenticide bait application in sugarcane crop were conducted in two districts of Punjab (India) during 2007–2010 for modification in already recommended practice. Sugarcane crop at all the experimental locations was surrounded by rice–wheat crops in rotation and infested predominantly with Bandicota bengalensis. Results of experiments conducted during 2007 and 2008 at two locations each revealed no significant difference in overall reduction in rodent activity and damage between fields given single (during October–November) and double (first in July and second in October–November) rodenticide treatments due to rapid rebuild up in rodent population after every treatment thus indicating the need of two treatments as per the previous recommendation. Results of experiment conducted during 2009–2010 at two locations revealed significantly (P \ 0.05) higher reduction in rodent activity and damage in fields given third treatment during December–January with 0.005% bromadiolone @ 2 kg/ha than in fields given third treatment with 2% zinc phosphide @ 2 kg/ha and fields given only first two treatments. This may be due to significantly (P \ 0.05) low acceptance of zinc phosphide bait compared to bromadiolone bait by rodents in these months. Present studies suggest that for protecting sugarcane fields from rodent damage at different crop stages, three rodenticide treatments, first in July, second in October–November with two rodenticide bai- tings @ 1 kg/ha each at the interval of 15 days and third treatment in December–January with single baiting of 0.005% bromadiolone @ 2 kg/ha may be applied. Keywords Rodenticides  Rodent damage  Rodents  Saccharum species hybrid  Sugarcane Introduction Sugarcane (Saccharum species hybrids), being an annual crop serves as a readily available source of high energy food and protective cover for feeding, burrowing and breeding activities of rodent pests, almost throughout the year (Parshad et al. 1986). The problems of rodent damage and control in sugarcane are particularly severe in tropical and subtropical Asia because here, small sized fields of sugarcane crop are surrounded by other short duration crops such as rice, wheat, oilseeds or vegetables (Parshad 1999). The sugarcane in such situations is subjected to a greater threat of rodent immigration from the surrounding fields (Ahmad and Parshad 1989) as a result of frequent disturbances in the latter due to ploughing, harvesting and flooding with irrigation or rainfall. An incidence of 10–30% cane cutting by rodents has been reported in dif- ferent parts of the world including India (Hampson 1984). In Punjab (India), rodents in sugarcane fields were found to cut 8.6% canes partially and 3.2% completely, resulting in a 6.4% loss in potential yield (Parshad 1987). Singla and Parshad (2010) reported average rodent damage of 19.12% in eleven villages of three districts of Punjab. Damage is caused mainly by gnawing through the rind of the lower internodes of canes and by damage to the roots during digging of burrows by rodents, particularly by Bandicota bengalensis and Nesokia indica (Parshad 1987; Khanzada 1995), which are highly fossorial. N. Singla (&)  B. K. Babbar Department of Zoology, Punjab Agricultural University, Ludhiana 141004, Punjab, India e-mail: neenasingla1@gmail.com 123 Sugar Tech (Jan-Mar 2012) 14(1):76–82 DOI 10.1007/s12355-011-0123-z