Flowering Characteristics and Yield of Maize Inbreds Grown for Hybrid Seed Production under Deficit Irrigation

The study of crop response to deficit irrigation is important for reducing agricultural water use in arid areas. Two experiments were conducted in an arid region of northwestern China in 2014 and 2015 to investigate the responses of the flowering characteristics (pollen shed by male inbreds, silk emergence of female inbreds) and yield components of maize (Zea mays L.) inbred lines to deficit irrigation at the vegetative (V) and flowering (F) stages. There were five irrigation treatments in each year, which were combinations of full irrigation (Stage 2), 50% of full irrigation (Stage 1), and no irrigation (Stage 0) at vegetative (V2, V1, V0) and flowering stages (F2, F1, F0). Results showed that kernel number (KN) ear(-1) had significant positive correlations with the total number of exposed silks ear(-1) (SNX), seed-set capacity (SC), silking rate ear(-1) (k(e)), silking rate of the female population (k(f)), and total pollen density at ear height (TPD) but that KN ear(-1) had a significant negative correlation with the anthesis-silking interval (ASI). Water deficit at vegetative or flowering stages reduced SN X, k f, k e, SC, and TPD. Water deficit at flowering stage increased ASI. Water deficit at both stages decreased KN ear(-1) and seed yield. There were no significant differences in pollen viability and kernel weight in any of the irrigation treatments. Treatment at V1F2 had no significant effects on flowering characteristics, KN ear(-1), or seed yield; however, it reduced the irrigation amount by 26% over the two stages. Thus, V1F2 is recommended as an optimum regime for limited irrigation in this region.