Effect of timings of water supply on dry matter partitioning and yield of mustard (Brassica juncea L.)

Non-Peer ReviewedRapeseed and mustard, two of the major oilseed crops, are widely grown in the world. With improvements in seed oil and meal quality, mustard can compete with rapeseed in the local as well as international markets, and it would be desirable to improve its yield. The effects of timing of water supply: at flowering, pod formation and ripening phases, in addition to one dry treatment on growth, total dry-matter production and partitioning of dry matter, and yield, were studied in mustard in the field during 1991 and 1992. Above-ground plant material was harvested at seven-day intervals, and dry-matter production was determined. Water supply had a substantial effect on both the total amount of plant-dry-matter produced and the pattern of its accumulation. The rate of accumulation of dry matter remained high under full water supply until the late-ripening phase. The maximum, of both the leaf and pod area achieved, was under full watering. The minimum supply of water increased the leaf area index (LAI) just after the start of flowering up to the maximum. Watering had significant effects (P<0.05) on yield. The full supply of water significantly increased seed yields by 57% and 44%in subsequent years, over the dry conditions (4002/2551 Kg, 199 -3080/2140 Kg, 1992). Application of water had an insignificant effect ( P>O. 05) on the harvest index (HI) . Water-use efficiency (WUE) was increased by 32% and 33% by the full supply of water in the consecutive years, over the minimum supply of water. It is concluded that three applications of an amount of water: at flowering, pod formation and ripening phases increase the seed yield by improving the photosynthetic (leaf and pod) area