Field screening of chilli germplasm collections for resistance to chilli thrips, Scirtothrips dorsalis Hood

Abstract

Forty chilli germplasm collections were field screened against chilli thrips, Scirthothrips dorsalis Hood during consecutive summer seasons of 2017-18 and 2018-19 under natural infestation conditions at All India Co-ordinated Research Project on Vegetable Crops, Odisha University of Agriculture and Technology, Bhubaneswar. Observations on the population of S.dorsalis were recorded at weekly interval from the appearance of the pest to last picking of the chilli fruits during all the seasons. Further the germplasm were visually rated for infestation of S.dorsalis in 0-4 point scale based on the ‘upward leaf curl’ damage symptom at 45, 60, 75, 90 and 105 DAT (Days After Transplanting). Mean population of S.dorsalis and per cent leaf curl index were computed which were further pooled to get aggregate mean population and leaf curl index over two seasosns. On the basis of this aggregate mean population and per cent leaf curl index values, none of the germplasm was found in highly resistant category. The germplasm collections viz., BC-7-2-1, BC-25 were identified as resistant whereas the genotypes viz., BC-79-1, BC-27-2-2, Utkal Abha (RC), BC-21 and BC- 406 were identified as moderately resistant categories. These may be further utilized as donor parents in developing the cultivars resistant to S.dorsalis.