Variability of Thermal Indices and Peak Mango Hoppers Incidence under Subtropical Conditions

Abstract

A 3-year study with 20-35 years old mango orchards of cv. Dashehari was conducted to study the mango hoppers and their thermal requirement association. Hopper populations significantly varied across seasons within a year. Lower populations (0.69-1.15 hoppers sweep-1) were recorded during 2011-12 as compared to higher populations of 1.32-4.03 hoppers sweep-1 during 2013-14. The highest population was observed during 10-22 standard meteorological week in each season coinciding with reproductive phase of mango. Thermal indices viz., growing degree days, heliothermal units and photothermal units were applied to estimate the peak hopper population in Lucknow region. A total of 1000°Cd GDD, 9265.2 HTU and 15169.5 PTU were required to reach the peak hopper incidence with significant linear relationships. These regression equations were explained up to 80-90% variations in mango hopper populations. The association between mongo hoppers and thermal indices could be used for prediction of peak incidence in Lucknow region for taking up timely management practices.