Effect of Water Stress during the Spike Growth Period on Wheat Yield in Contrasting Weather

CANTARERO, M.G.; ABBATE, P. E.; BALZARINI, M.

International journal of environmental & agriculture research

IJOEAR

Año: 2016 vol. 2

he effect of water deficit on spring wheat yield (Triticum aestivum L.) was analyzed focusing on crop growth and dry weight partitioning during the spike growth period (SGP). Two levels of water availability (rainfed and irrigated) were tested in two locations (Córdoba and Balcarce, Argentina). The degree of source limitation for grain filling was greater under rainfed conditions (12%) than under irrigation (5%); however, water stress affected yield by 40% (mean of all experiments), mainly through grain number m-2 (GN) rather than by differences in weight per grain. The decrease in GN due to water stress was associated with spikes dry weight (SDW = total spikes weight ? grain weight) measured 7 days after anthesis, but some additional experiment effect was detected on GN. Analysis of different weather variables showed the vapor pressure deficit (VPDX) as the one that best explained GN deviations. A model for GN estimation with or without water stress, was developed including the effec