Seasonal incidence of grape vine thrips and their correlation with weather parameters

Abstract

The studies on seasonal incidence of grape thrips, Rhipiphorothrips cruentatus Hood (Thripidae: Thysanoptera) were carried out at All India Co-ordinated Research Project (AICRP) on Fruits, Department of Horticulture, MPKV., Rahuri, during 2017-18. The studies on seasonal incidence revealed that the incidence of active stages both nymphs and adults started appearing from November 1st week (7.88/shoot) when new flush started after fruit or forward pruning in October, 2017. The population gradually increased and peak incidence was observed from second week of December (50thstandard meteorological week) i.e., (8.28/shoot) to second week of January (2ndstandard meteorological week) i.e., (8.53/shoot). The higher incidence of thrips was coincided with the flowering stage of grape vine. The linear correlation studies revealed that the weather parameters viz., maximum (r = -0.558) and minimum temperatures (r = -0.419) are significantly negative correlated with thrips incidence. Whereas, it had significant positive correlation with both morning (r = 0.474) and evening relative humidity (r = 0.233).While all other weather parameters such as rainfall (r = 0.092NS), sunshine (r = -0.094NS) and wind velocity (r = -0.130NS) have not shown any significant relationship with population of thrips.