Effect of Moisture Stress at Different Stages of Growth I. Comparison of a Single‐Eared and a Two‐Eared Corn Hybrid¹

Abstract

Single‐eared (Hy × C103) and two‐eared (R71 × B60) corn (Zea mays L) hybrids were grown with their roots confined in 8− ✕ −24‐inch plastic‐lined, soil‐filled trenches. They were subjected to equally severe moisture stress at tassel emergence, silking‐pollination and blister kernel stages. The two‐eared variety was more tolerant to moisture stress at the pollination and blister kernel stages than the single‐eared variety. There was no significant difference in the total grain yield of the varieties to the moisture stress at tassel emergence. Silking was delayed in both varieties during moisture stress at pollination; however, this delay in silking did not reduce the fertilization of the ears and the grain yields of the two‐eared variety as much as the single‐eared variety. The two‐eared variety extracted significantly more water (1–2%) from the soil when under moisture stress. A method for measuring the relative turgidity (RT) of the leaves of the corn plants was developed, and the RT of each leaf on the corn plant was different. The RT decreases from apex to base, with each succeeding leaf. Moisture‐stressed corn plants had RT values 18 percent lower in the leaves near the ear shoot than in the leaves near the tassel. This difference in RT could account for the lack of silk emergence while the tassels continued to shed pollen.

Differential Response in the Water Status of Immature and Mature Fronds of the Ostrich Fern (Matteuccia struthiopteris [L.] Todaro) to a Mild Water Stress

“…Experimets were condueted In growth h ers to examine the effect of a mil water stress (-200 (2,6,9,14). Catsky (5) noted that young leaves received a preferential portion of the water supply and that, under large water deficits, water was translocated from older leaves to younger leaves.…”

Corn yield response to moisture stress and foliar fertilizer during grain fill

“…Prolific com varieties have shown greater flexibility for adjusting to environmental stress (Hallauer and Troyer, 1972) and would seem to provide a means of further compensation for moisture-stress effects that might occur during the silking period for the first ear. Indeed, Barnes and Woolley (1969) did find their two-eared variety to suffer only 14% yield reduction from moisture stress near silking compared with 73% yield reduction for a par ticularly sensitive single-eared variety. This tolerance, however, resulted more from an ability to develop the first ear than to compensate with second ears.…”

“…In an attempt to define the effect of time of stress more precisely, Shaw (1970a, 1970b) grew corn in 76 liter containers in a field plot that could be covered by a movable shed to withhold rainfall and applied stress during nine time periods throughout the growing season. Others (Barnes and Woolley, 1969;DeJager, 1971a, 1971b;Wilson, 1968aWilson, , 1968b have sought to elucidate the yield response of corn to moisture stress by using similar techniques to apply stress during short, defined time periods. A somewhat different approach was used by Jurgens et al (1978), who tried to maintain their corn plants in containers at a nearly constant high, or low, soil-water potential throughout the grain-filling period.…”

Computer simulation of the irrigation potential of selected low water holding capacity soils

“…Runge (1968) concluded from his study of rainfall and temperature in teractions on corn yield in Illinois that corn was sensitive to soil-moisture stress during a period before pollen shedding. Barnes and Woolley (1969) investigated the influence of moisture stresses at different stages of development for two hybrids; one with a tendency to produce two ears, and the other with a single-eared habit, but known to be highly susceptible to moisture deficiencies. Moisture stress during the silking and blister kernel stages reduced yields markedly for the single-eared hybrid.…”