Seasonal Abundance of Onion Thrips, thrips Tabaci Lindeman

An experiment was conducted at University of Agricultural Sciences, Dharwad, Karnataka, India during 2009-2010, 2010- 2011 and 2011- 2012 to find out the thrips population attacking onion sowing at different dates to determine the optimum date(s) of sowing. There were twelve transplants in 2009-2010, sixteen transplants in 2010-2011 and 2011- 2012. Results indicated that in 2009-10, November 1st transplanted seedlings had a peak population of onion thrips in protected (8.95 thrips/plant) as well as in unprotected plots (53.30 thips/plant). Where as in 2010-11 and 2011-12, December 1st transplanted seedlings had a peak population of thrips. i.e. 10.75 thrips/plant in protected plot and 55.49 thrips/plant in unprotected plant (2010-11) and 11.58 thrips/plant in protected plot and 57.83 thrips/plant in unprotected plant (2011-12). The seedlings transplanted in Rabi season had peak thrips population compared to Kharif season transplanting dates. Therefore, the findings of this work revealed that onion thrip in Dharwad, Karnataka breed from November 1st to January 1st with a peak in December.