Effect of weather on seed yield and radiation and water use efficiency of mustard cultivars in a semi-arid environment

• Optimization of date of sowing and cultivars of Indian mustard was done for enhancing productivity.
• We attempted to compute radiation and water use efficiency of Indian mustard under varied crop growth environments.
• We developed evapo-transpiration production function and radiation production function for Indian mustard.

The date of sowing of Indian mustard (Brassica juncea) varies from year to year depending upon the harvesting of previous wet season crop in the northern and north-western part of India, which exposes the mustard crop to variable weather conditions. So an experiment was conducted in Indian Agricultural Research Institute research farm to study the interactive effect of variable weather and cultivars on yield, radiation and water use efficiency of mustard. In this experiment, split plot design was adopted with date of sowing (early, normal and late) as main plot treatment and mustard cultivars (Pusa Gold, Pusa Jai Kisan and Pusa Bold) as subplot treatments. Pooled over the years, mustard seed yield, radiation and water use efficiency was significantly (p = 0.05) lower in late sowing compared to early sowing (by 46, 32 and 40%, respectively) and normal sowing (by 44, 26 and 41%, respectively). Early sowing and normal sowing were statistically at par with respect to mustard seed yield and water use efficiency. Among the cultivars, Pusa Jai Kisan and Pusa Bold were statistically at par with respect to seed yield, radiation and water use efficiency whereas Pusa Gold registered significantly lower seed yield, radiation and water use efficiency compared to the cultivars Pusa Jai Kisan (by 55, 23 and 52%, respectively) and Pusa Bold (by 56, 20 and 54%, respectively). There was significant interaction between date of sowing and cultivars with respect to seed yield, radiation and water use efficiency of mustard. From the above study it was concluded that normal or early sowing of the Pusa Jai Kisan or Pusa Bold cultivar may be practiced for achieving higher seed yield, radiation and water use efficiency in the semi arid environment of north and north-western part of India