Productivity response of some maize (Zea Mays L.) hybrids to stress and nonstress irrigation water [electronic resource].

Includes references.

Water deficit reduces grain yield of maize and other grain crops. The objectives of this study were to assess the productivity often maize hybrids (SC.IO, SC.125, SC.129, SCI 55, SCI62, TWC311, TWC32I, TWC324, TWC327 and TWC352) under two varying water supplies (100 and 75% from adequate amount), to assess the level of tolerance of the schybrids under water deficit and to determine the associations among hybrids performance under adequate and deficit water conditions. The results showed that water deficit caused significant decreases in grain yield and other agronomic traits. The losses of grain yield, as affected by water deficit, across single-cross hybrids. were significantly higher than three-way hybrids. Under adequate water, SCIO and TWC324 gave the highest grain yield across years (10.52 and 9.71 Mg ha,l), while, under deficit water, TWC321, TWC327 and SCl62 had the highest grain yields (8.26,7.19, and 7.62 Mg hal, respectively). Grain yield reduction, due to water deficit. ranged from 6.0 to 30.5% for the tested hybrids. According to susceptible index (SI), TWC321 and TWC327 were tbe most tolerant bybrids to water deficit (0.27 and 0.33), followed by TWC311 (0.64), SC129 (0.72) and TWC352 (0.78). According to drought tolerance efficiency (DTE), TWC321 and TWC327 hybrids had the highest mean (94 and 92%). According to drought depression percentage (DD %), TWC321 and TWC327 had the lowest values (6.0 and 8.0%). Therefore, tbese hybrids might be more tolerant to water deficit. The results showed that water deficit was increased in the anthesis-silking interval (ASI) and silk emergence was delayed. SCI29 was the least delayed hybrid under water deficit. For ASI, the lowest affected hybrids were SCI62 and SC129. Significant positive correlation was observed between grain yield depression and 81 (r = 0.99, p::S 0.01). Also, Significant negative correlation was observed for DTE with both graio yield depression and SI (r = -0.99, P '" 0.01). Significant positive correlation was observed between GYodq and GYd'f (r = 0.66, P '" 0.05). It might be concluded tbat SClO and TWC324 were the best bybrids under optimum conditions, wbile, TWC321 and TWC327 were more suitable bybrids under deficit water conditions.

Summary in Arabic.

1