Population dynamics of Thrips (Thrips tabaci Lind) on onion in relation to abiotic factors

摘要

The experimental findings of two years crop seasons i.e; 2013-14 and 2014-15 revealed that the activity of thrips on onion gradually increased from 6lh standard week of February and continued up tol7th standard week of April, with maximum thrips population (69.77 thrips/plant) was recorded during 14th standard week of April when the corresponding maximum, minimum temperature and relative humidity at 07 and 14 hrs during the period were 33.50,18.50 °C, 91.95 and 56.70 percent respectively. The maximum temperature and minimum temperature showed positive influence on thrips population (r=0.687 and 0.496), relative humidity at 7 hrs and rainfall showed significant negative effect (r=-0.638 and -0.506, respectively).