Growth and N-uptake by wheat as affected by sowing date and nitrogen in irrigated semi-arid conditions

Abstract

Field experiments were made under irrigated semi-arid conditions to determine the effects of sowing date and nitrogen application on the growth and yield of wheat and nitrogen-uptake by wheat plants. Early sowing was found to be favourable to high grain production because the post-anthesis period coincided with relatively lower temperatures. Late sowing was unfavourable to grain yields since the period between anthesis and leaf senescence was curtailed by the onset of relatively higher temperature. The benefits from nitrogen were greater with early sowing because of higher nitrogen-uptake during early vegetative growth as a consequence of which, nitrogen was readily available to the plants. This resulted in better leaf expansion, and higher leaf-area indices and leaf-area duration. With late sowing nitrogen-uptake was much lower during early vegetative growth and this resulted in decreased leaf expansion, reduced leaf-area indices and leaf-area duration and therefore diminished response in grain yield to nitrogen application.

Productivity and nutrient uptake of newly released wheat varieties at different sowing times under poplar plantation in north-western India

“…Similar findings were reported by Dubey and Sharma (1996). Khalifa et al (1977) observed that nitrogen uptake was higher during early sowing (1st November) of wheat, which resulted in better leaf expansion, higher leaf area indices and higher leaf area duration. On the other hand, nitrogen uptake was much lower in late sowing (6th December) of wheat, which resulted in decreased leaf expanses, reduced leaf area indices and leaf area duration and thus lower grain production.…”

Soil and water conservation for optimizing productivity and improving livelihoods in rainfed areas

“…Yield reductions in latesown wheat is often attributed to inadequate tillering and reduced transpiration late in the season (Doyle and Fischer 1979). High seeding rates can offset much of the adverse effect of late seeding (Khalifa et al, 1977;Doyle and Fischer 1979). For other situations the cause for low yields may be related to occurrence of pests and diseases associated with the sowing date.…”