Time for stopping irrigation on wheat crop

Abstract

The objective of this study was to evaluate the effect of stopping water application on wheat (cv. BR- 12 Aruanã) at 69, 77, 85, 95, 102 and 115 days after the planting date, which corresponds to the developmental stages; of beginning of anthesis, water caryopsis, medium ripe, soft dough, hard dough and hard caryopsis on yield and grain quality. Ali experimental plots were irrigated when soil water tension measured at a depth of 10 cm reached a value of 48 kPa until the developmental stage when irrigation water supply stopped in cach treatment. A significative reduction in yield was verified when water supply stopped before soft dough stage. Reduction in yield was caused mairily by the reduction in 1,000-grain weight and hectoliter weight. To obtain maximum hectoliter weight, irrigation must: be maintained until hard dough stage. Stopping irrigation at hard dough stage caused an economy of 99 mm of water in relation to the treatment: irrigated until hard caryopsis. The developmental stage of hard dough grain can be defined in ficid as the stage: when most of the grains allow to make a finger-nail impression or furrow but the grain content can not be squeezed out.