Population dynamics of thrips (Taeniothrips simplex) on sword lily (Gladiolus hybrida) and varietal response to them in sub-humid Southern region of Rajasthan

Twenty five varieties of sword lily were screened against thrips. Variety Phule Ganesh (dark red) and Green Willow (yellow colour) were found to be highly susceptible to thrips with population of 20.86 and 20.82 respectively and recorded the maximum foliage damage (76.32 and 86.11%). While Suchitra (light yellow) variety was least susceptible to thrips with a population of 7.80 throughout the crop period and also showed lowest damage (20.51%) to foliage. Further, light coloured varieties were less susceptible to thrips as compared to dark coloured varieties. The incidence of thrips initiated in the fourth week of December 2016 (52th Standard metrological week) on all varieties except variety Suchitra on which the incidence of thrips was observed in first week of January 2017 (1st Standard metrological week). Thrips remained active throughout the crop season. Initially, the population of thrips was very low and gradually increased (12th SMW) and reached to its peak on 26th March, 2017 at the full maturity of flowers in all varieties. The population of thrips evinced a positive significant correlation with mean atmospheric temperature and negative significant correlation with mean relative humidity.