Efficacy of dimethoate and monocrotophos in controlling mango shoot gall psyllid, Apsylla cistellata Buckton.
Gajendra Singh, Satnam Singh
Author Affiliation: Govind Ballabh Pant Univ. Agric. & Technology, Pantnagar-263?145, Uttar Pradesh, India.
Indian Journal of Plant Protection 12 : 1-7
Abstract : Field trials were carried out in India to determine the effects of 3 starting dates (15 and 31 August and 15 September), 3 concentrations (0.03, 0.045 and 0.06%) and of 2 and 3 sprays of dimethoate and monocrotophos on the control of shoot gall formation by the psyllid Apsylla cistellata on mango. Observations on the mortality of nymphs feeding at oviposition sites in the midrib indicated that dimethoate was most effective when applied on 15 August, while monocrotophos was most effective when applied on 31 August or 15 September. Three sprays were more effective than 2, and 0.06% was the most effective concentration. Gall formation was completely inhibited when either of the compounds was applied on 15 August, 2 or 3 sprayings were carried out and any of the 3 concentrations was used. Effectiveness was reduced significantly when spraying was delayed until 31 August or 15 September. However, monocrotophos was more effective than dimethoate when spraying was delayed, and 0.06% was the most effective concentration under these conditions; 0.045% was also effective in controlling gall formation when 3 applications were made.