Indian Agricultural Research Institute, New Delhi-110012
*A part of M. Sc. thesis submitted by the senior author to P. G. School, I. A. R. I., New Delhi under the guidance of the second author.
Studies to investigate the extent of variability and inter-relationship between seed yield and its contributing attributes were undertaken in onion during 1970–71, at the Division of Vegetable Crops and Floriculture, Indian Agricultural Research Institute, New Delhi. Observations recorded on nine different traits indicated highly significant varietal differences in respect of all the characters. The heritability estimates worked out were quite high (89.14–98 45 per cent). The expected genetic advance was also very high for number of flowering stalks (89.55 per cent), seed yield (77.44 per cent) and quite high for number of seeds per head, number of leaves and number of tillers.
Highly significant positive correlation were observed with seed yield on one hand and number of flowering stalks (r = 0 6914), number of tillers (r = 0.6103) and number of leaves (r = 0.4809) on the other hand, but there was highly significant negative correlation between seed yield and days taken to flower (r = 0.3803). Amongst the yield contributing characters, number of flowering stalks number of tillers and number of leaves had significant positive correlation among themselves. Height of flowering stalks, size of flowering head, days taken to flower and number of seeds per head also showed significant positive correlation among themselves and a negative correlation with 1,000 seed weight.
It was concluded that the number of flowering stalks, number of tillers and number of leaves may serve as the measurable components of seed yield.
