Screening of onion (Allium cepa L.) three-way hybrids and their parents for foliage characteristics

Foliage study has been considered as an important trait for the onion with respect to predilection of insect-pests. Leaves colour (Green to dark green) and character (Glossy to waxy) has been highly correlated to nourishing of pest like thrips. Onion thrips prefer dark green to light green foliage with wax coating then the glossy to semi glossy leaves having green and light green colour. The screening of hybrids developed through three-way cross and their parents for favourable leaves appearances and dislike by onion pest, would be helpful for identifying the best genotype(s) and minimize the infestation. Forty-four genotypes were evaluated at research experimental plot of Indian Institute of Horticultural Research, Bengaluru (India). They were categorized based on foliage colour scale and waxiness scale. Twenty-six genotypes were grouped under glossy to semi glossy appearance and eighteen were included as waxy. There were 9, 19 and 16 genotypes were observed for green, light green and dark green, respectively, foliage expression. The crosses L1 x T4, L1 x T5, L2 x T4 and L2 x T5 were possessed light green leaves and semi-glossy foliage’s and least preferred by the thrips for feeding leaves. The results were indicated that semi-glossy phenotype may protect foliage from this pest. Therefore, these crosses could be grown for healthy vegetative growth and conceivably high bulb size and yield of onion.