Interactive Water and Nitrogen Effects on Senescence of Maize. I. Leaf Area Duration, Nitrogen Distribution, and Yield

Abstract

Stress effects on leaf senescence are important for maize (Zea mays L.), since production of new photosynthetic area is genetically pre‐determined. Interactive effects of water and N deficits on water potential components, green leaf area (GLA) duration, and N and biomass allocation during grain filling were evaluated in a 2‐yr field study conducted on Yolo loam (fine‐silty, mixed, nonacid, thermic Typic Xerorthents) under four treatments: 180 kg N/ha applied at planting, with (NI) and without (ND) irrigation; and no N fertilizer, with (OI) and without (OD) irrigation. Leaves of low N plants had reduced capacity for solute accumulation, and both water and N deficits caused 0.1‐ to 0.5‐MPa reductions in midday leaf turgor. Total GLA was smallest in the OD treatment, but senescence during grain filling was greatest in the ND treatment because of a high transpiration demand and a high reproductive sink demand for N. Ear removal reduced the rate of post‐anthesis leaf N decline of all treatments, and plants in the ND treatment showed a significant reduction in leaf senescence rate when ears were prevented. Grain yield of the OD treatment was <50% of NI yield in both years; ND and OI treatments had intermediate reductions. Although the timing and intensity of stress differed between treatments and years, both water and N deficits reduced leaf longevity, and GLA duration from anthesis to harvest was linearly related (r2 = 0.92) to final grain dry weight.

Effect of nitrogen rate and fertilizer nitrogen source on physiology, yield, grain quality, and nitrogen use efficiency in corn

“…Thus, it appears that NDVI is relatively insensitive to a 3% increase in Chl a or a 6% increase in Chl a + b content, and a 10% increase in stover biomass was obtained at 200 kg N ha −1 compared to 150 kg N ha −1 . The photosynthetic rate is shown to be correlated with leaf N concentrations (Wolfe et al 1988;Muchow and Sinclair 1994). In our study, the application of 100 and 200 kg N ha…”

Growth analysis of winter wheat cultivars as affected by nitrogen fertilization / Wachstumsanalyse von Winterweizensorten in Abhängigkeit von Stickstoffdüngung

“…Thorne (1973) mentioned the great dependence of grain yield on leaf area index. Positive associations between green leaf area duration and grain yield have been observed in a range of cereals, including wheat (Evans et al, 1975), maize (Tollenaar and Daynard, 1978;Wolfe et al, 1988), oats (Helsel and Frey, 1978) and sorghum (Borrell et al, 2000). Flag-leaf photosynthesis in wheat contributes about 30-50% of the assimilates for grain filling (Shearman et al, 2005), and the onset and rate of senescence are clearly important factors for determining resistance to abiotic stress.…”

Nitrogen fertilization impact on agronomic traits of maize hybrids released at different decades

“…Nitrogen limiting conditions produce several restrictions to plant development, delaying silking (Russel, 1991), decreasing pre-anthesis crop growth rate (McCullough et al, 1994a), dwindling leaf area index at flowering and accelerating leaf senescence rates throughout the life cycle (Wolfe et al, 1988).…”