Impact of soil moisture stress during the silk emergence and grain‐filling in maize

Abstract

Suboptimal soil moisture during the growing season often limits maize growth and yield. However, the growth stage‐specific responses of maize to soil moisture regimes have not been thoroughly investigated. This study investigated the response of maize to five different soil moisture regimes, that are, 0.25, 0.20, 0.15, 0.10, and 0.05 m3 m−3 volumetric water content (VWC), during flowering and grain‐filling stages. Sub‐optimal soil moisture at the flowering and grain‐filling stages reduced ear leaf stomatal conductance by 73 and 64%, respectively. An increase in stress severity caused significant reductions in ear leaf chlorophyll content and greenness‐associated vegetation indices across growth stages. Fourteen days of soil moisture stress during flowering delayed silk emergence, reduced silk length (19%), and silk fresh weight (34%). Furthermore, sub‐optimal soil moisture caused a significant reduction in both kernel number (53%) and weight (54%). Soil moisture stress at the flowering had a direct impact on kernel number and an indirect effect on kernel weight. During grain‐filling, disruption of ear leaf physiology resulted in a 34% decrease in kernel weight and a 43% decrease in kernel number. Unlike grain‐filling, treatments at the flowering significantly reduced kernel starch (3%) and increased protein by 29%. These findings suggest that developing reproductive stage stress‐tolerant hybrids with improved resilience to soil moisture stress could help reduce the yield gap between irrigated and rainfed maize.

Negative Synergistic Effects of Drought and Heat During Flowering and Seed Setting in Soybean

“…As an adaptive strategy (differential transpiration) under interactive heat and drought, plants close leaf stomata while flower and pod stomata remain open (Cohen et al, 2021b; Sinha et al, 2022). Whereas comparatively higher transpiration was observed in the reproductive tissue than the vegetative as a protective mechanism to avoid overheating (Sinha et al, 2022; Vennam et al, 2023a). The canopy temperature, an integrative trait that reflects the plant water status, increased by 8 °C under combined stress had a pronounced disruption of photosynthesis and stomatal conductance, consistent with previous study (Cohen et al, 2021b).…”

Identifying Crop Growth Stages from Solar-Induced Chlorophyll Fluorescence Data in Maize and Winter Wheat from Ground and Satellite Measurements

“…Moreover, not all growth stages have an equal impact on crop yield. For instance, in maize cultivation, the silking stage is highly sensitive to water stress, necessitating meticulous irrigation management [51,52]. Additionally, the V5 and jointing stages, when the stem of maize grows fast described in Table 1, demand increased attention due to maize's heightened need for nitrogen fertilizer and water during these phases [53][54][55][56][57].…”

Unveiling Drought-Tolerant Corn Hybrids for Early-Season Drought Resilience Using Morpho-Physiological Traits

“…Kukal and Irmak [9] reported that corn had the greatest irrigation-limited yield gap globally among the major rainfed crops, with an increase of 2.7 times in yield under irrigated conditions. During critical growth stages, moisture stress severely affects corn plant growth and development, resulting in reduced plant stand, reproductive failure, and yield [10].…”