Govind Ballabh Pant University of Agriculture and Technology, Pantnagar-263 145, U.P.
Experiments were conducted to find out the effect of three starting dates (15 and 31 August and 15 September), three concentrations (0.03%, 0.045% and 0.06%) and of two and three number of sprays of dimethoate and monocrotophos in controlling shoot gall formation by Apsylla cistellata in mango.
Observations recorded on the mortality of embryos feeding at ovipositional sites in the midrib indicated that dimethoate was more effective when sprayed on 15th August as compared to monocrotophos which was better when sprayed on 31st August and 15th September. 0.06% concentration was superior to 0.045% and 0.03% Similarly three number of sprays were effective than two sprays.
Gall formation was checked cent percent when any of the insecticides was sprayed at 15th August with either two or three number of sprays and with any of the three concentrations. The efficacy was significantly reduced when spraying was delayed to 31st August or again to 15th September.
However, monocrotophos proved better as compared to dimethoate when spraying was delayed to 31 August or 15 September, and 0.06% concentration was more effective in such conditions. 0.045% also pve control of gall formation when three number of sprays were given.
