Comparative studies of brodifacoum and zinc phosphide against field rats in wheat crop in Tehsil Ghazi, district Haripur [Pakistan]

The field rat species found in the study area were Bandicota bengalensis (Gray and Hard, Tatera indica Hard, Mus musculus Linn. and Nesokia indica Gray and Hard. The efficacy of zinc phosphide plain (2%), zinc phosphide was coated (2%) and brodifacoum (0.005%) was evaluated. With zinc, phosphide plain (2%) an overall reduction of 67.43% in live burrows was recorded after three treatments and an estimated mortality of 77.498% was calculated. With zinc phosphide wax coated (2%), an overall reduction of 83.374% in live burrows was recorded after three treatments and an estimated mortality of 88.524% was calculated. With brodifacoum (0.005%), an overall reduction of 67.704% in live burrows was recorded after three treatments and an estimated mortality of 77.086% was calculated. Whereas in control plot, an overall increase of 56.789% in live burrows was recorded after three treatments and an estimated mortality decrease of 49.382% was calculated. The relative post-treatment reduction tracking tiles activity with zinc phosphide plain (2%) zinc phosphide wax coated (2%) and brodifacoum (0.005%) was 38.890 %, 31.112% and 36.112%, respectively, whereas it was 21.666% in reference (untreated) site. The damage was recorded from treatment and non-treatment sites. With zinc phosphide plain (2%), zinc phosphide wax coated (2%) and brodifacoum (0.005%), an overall reduction, in cut/damage stalks, of 39.250%, 48.630% and 24.430% was computed after treatment, whereas in reference plot an increase in stalk damage of 29.810% was calculated. Research data obtained against field rats in wheat barani field revealed that an effective burrow rat control was obtained with zinc phosphide wax coated 2% (83.374% decrease), followed by brodifacoum 0.005% (67.704% decrease) and zinc phosphide plain 2% (67.432% decrease) in burrow activity as compared to an increase of 56.789% in control plots. The estimated mortality varied from 77.086% to 88.524% in treated plots as compared to an increase of 49.382% in control plots. The tracing tile activity reduction (% positive) with various rodenticides varied from 31.112% to 38.890% in treated plots as compared to an increase of 21.666% in control plots. The stalk damage reduction varied from 24.430% to 48.630% in treated plots as compared to an increase of 29.810% in control plots. All the three rodenticides proved effective in reducing rodent population and caused heavy mortality in barani wheat crop in Tehsil Ghazi District Haripur in 1998. On the whole, zinc phosphide wax coated 2% gave higher rodent population control followed by brodifacoum 0.005% and zinc phosphide plain 2%.