Beginning and ending times of irrigation by soil inundation for rice, Bluebelle cultivar

Abstract

To study the effect of beginning and ending times of irrigation on paddy rice yield, an experiment was carried out in a Pelotas soil (Planosol) during three crop seasons, in the experimental field of EMBRAPA-UEPAE Pelotas Station. Twelve treatments of three irrigation starting time combinations (14, 28 and 42 days after seedling emergence) and four irrigation ending times (70, 84, 98 and 112 days after seedling emergence) were carried out. The cultivar used was Bluebelle. There was no interaction among starting and ending of irrigation times; the treatment effects on rice yields did not vary along the three crop seasons. The delay of irrigation starting from 14 to 28 days after seedling emergence did not affect grain yield. However, when it was postponed to 42 days after seedling emergence, there was a harmful effect in yield. On the other hand, yield was not affected by the ending of irrigation times, when water supply to the crop was suspended 70 days after seedling emergence (ten days before flowering onset). Regarding mill yield, it was found out that it decreased slightly as irrigation starting was delayed, but increased as irrigation ending was hastened.