Effects of soil water-deficits during tassel emergence on development and yield component of maize ( Zea mays)

Abstract

Water-deficits during flowering and pollination can cause considerable reductions in yields of determinate crops due to influences on reproductive components. This study was conducted to determine how different levels of soil water-deficit during emergence of tassels influence silking and yield components of maize. A rain shelter provided timely water-deficits in a field environment during 1987 on a sandy soil in Michigan. Yield reductions in excess of 90% occurred when water-deficits spanned the interval from just prior to tassel emergence to beginning of grain-fill. Emergence of tassels and silks was delayed more than two weeks. Final internode lengths reflected reductions in plant extension growth, and evaluation of lengths of individual internodes depicted the windows of development in which plants were most affected by water-deficits. Grain number was reduced in proportion to the duration of the water-deficit period. Assessment of grain and non-grain above-ground biomass 100 days after sowing demonstrated that both were reduced by severe water-deficits, but not to the same degree. There was delayed development in response to the severe water-deficits, as was apparent from 75% silking dates and biomass assessments.