Design and development of coconut ultra-low volume climbing sprayer

Abstract

The investigation on “Seasonal Incidence of Thrips (Thrips tabaci Lindeman) Infesing Onion” was conducted at Instructional Farm and Department of Entomology, Rajasthan College of Agriculture, Udaipur during kharif, 2024. The study on the seasonal incidence of thrips reveal that the infestation of thrips commenced in the first week of August (32nd standard meteorological week), with its peak of 16.07 thrips per plant in the second week of September (38th SMW) and declined during the last week of October (41th SMW). The maximum temperature (32.6 °C) and sunshine (6.3 hr) during the peak period showed a significant positive correlation with thrips population (r = 0.644* and r = 0.745*, respectively) whereas morning and evening relative humidity, minimum temperature, wind velocity and rainfall exhibited non-significant negative correlation (r = -0.475, -0.582, -0.287, -0.483, -0.136, respectively). The maximum percent damaged leaf number of 21.33 percent per five plants was recorded during 38th standard meteorological week (SMW). While the minimum percent damaged leaf number of 3.33 percent per five plants, during 32nd SMW.