1Central Potato Research Institute, Shimla-171 001, (H.P.).
2Chemistry Department, Himachal Pradesh University, Shimla-171 005, (HP).
*Publication No. 1558, CPRI, Shimla, Part of Ph.D. thesis approved to H.P. University by the senior author.
Controlled Studies conducted on acidic soils of Fagu (Shimla) on the effect of three organophosphate pesticides i.e. phorate, chloropyrifos and metasystox on the bio-anions composition of potato cv. Kufri Jyoti revealed a significant increase in P and S concentrations in leaf and stem at 10, 20 and 30 days after their soil application. At 10 days, the increase was highest with chloropyrifos but lowest with phorate. The long term effect on P concentration in potato plant, however, was more in presence of phorate than with other two pesticides. Post harvest soil analysis indicates higher residual Bray P (2–20 ppm) and available S (2–8 ppm) contents in the soil at 10 and 20 days. The increase in available P was mainly in form of Sal-P, Al-P and Ca-P indicating more P availability to potato from these fractions. Fe-P fraction, however, showed a decreasing trend with time.
