EFFECTS OF EXCESS SOIL WATER ON SWEET CORN YIELD

Abstract

ABSTRACT An experiment was conducted on silt loam alluvial soil in Louisiana to determine the yield response of sweet com to excess soil water stress and to determine crop susceptibility factors during vegetative and tasseling/silking stages of growth. Sweet com yield from 40 m2 plots that received excess soil water stress treatments (high water table within 30 cm of the soil surface) of three, six-, and nine-days duration during vegetative and tasseling/silking stages was usually significantly less than yield from the control (drained/irrigated) treatment. Average yield among treatments was lowest from the nine-days stress duration. Yields of sweet corn stressed for nine days during the vegetative and tasseling/silking stages were 77 and 61% less, respectively, than those from the drained/irrigated treatment. Normalized crop susceptibility factors, based on weight of marketable corn, were 0.55 and 0.45 for the vegetative and tasseling/silking stages, respectively. These factors indicate that sweet com is highly susceptible to excess soil water stress during both stages of growth but usually more so during the vegetative stage. Correlating the relative com yield (marketable weight) with Stress Day Index values indicated that relative com yield decreased 0.62% for each one-unit increase in the Stress Day Index. Fifty-four percent of the variation in relative sweet com yields was explained by Stress Day Index.