Insect pest spectrum on ajwain, Trachyspermum ammi L. genotypes under eastern dry zone of Karnataka

Abstract

An experiment was conducted with fourteen ajwain genotypes at the Department of Plantation, Spices, Medicinal and Aromatic Crops, College of Horticulture, GKVK, Bengaluru, from October 2019 to April 2020 to document insect pest spectrum infesting ajwain. Out of the four insect pests recorded to invade ajwain, three are new pest records on ajwain except aphids. Only the aphid could differentiate the ajwain genotypes and rest three failed to do so due low pest pressure. Irrespective of genotypes, the mean pest population was 2.23 defoliators per plant (Thysanoplusia orichalcea and Archips sp. together), 4.98 per cent stem fly infestation which caused 1.73 per cent plant mortality per 3.8 m2 plot and 61.85 aphids per 5 cm apical shoot. Aphid population was significantly least on genotype, Lam Sel-1 (43.37) and AA-2 (51.43) and was maximum on DAC-8 (71.90) which indicates scope for exploring the variability for aphid in crop improvement programme.