Yield enhancement by short‐term imposition of severe water deficit in the vegetative growth stage of grain sorghum

Abstract

Water deficit is generally thought to negatively impact crop yields, including grain sorghum (Sorghum bicolor L.), but a small body of literature reports changes in crop physiology and growth in plants with short‐term imposition of water deficit during vegetative development that could lead to increased yield. In a replicated and repeated pot experiment in which water deficit was imposed for 10‐day periods in grain sorghum plants that were otherwise well‐watered, we tested the hypothesis that relatively severe, short‐term water deficit imposed during early vegetative development could enhance grain sorghum yield. The results showed that severe water deficit (~30% of control ET) imposed during two vegetative periods enhanced grain yield compared to continuously well‐watered plants by 21% (p = .0356). Grain yield was correlated with average grain weight, grain number per head and shoot‐to‐root ratio. Yield enhancement was associated with a substantial shift in resource partitioning, as water deficit reduced root mass (p = .0032), stem/leaf mass (p < .0001) and total biomass (p = .0005), resulting in a 60% increase in harvest index. Imposition of water stress during vegetative growth in sorghum can increase grain yield.

Root system architecture, physiological and transcriptional traits of soybean (Glycine max L.) in response to water deficit: A review

“…The effect of drought on the root system varies with different drought patterns and degrees. In the vegetative growth stage, pod stage and grain filling stage, the root:shoot ratio gradually decreased with the increase of soil water content, and the effect of drought on the aboveground part was greater than that on the root system (Adams and Erickson 2017). Drought reduced root biomass and increased root:shoot ratio (Yanqi et al 2018).…”

Root distribution patterns of peanut genotypes with different drought resistance levels under early‐season drought stress

“…() suggests that plants respond to drought by physiological adaptations that tend to equalize the exchange root: shoot ratio (Bloom et al., ; Kulkarni & Phalke, ; Polania et al., ). The concept that plants stimulate or maintain root growth at the expense of shoot growth in response to drought has also been mentioned by Adams and Erickson () and Anyia and Herzog (). In this study, the responses for shoot dry weight and leaf area were in the similar patterns among peanut genotypes as all peanut genotypes reduced shoot dry weight and leaf area in responses to early‐season drought.…”

Combining yield, earliness and plant height in a single genotype: a proposal for breeding in grain sorghum (Sorghum bicolor L.)

“…Initially, a joint analysis of variance was performed according to the statistical model described below: (1) where: Y ijk = the observation in the k-th block, evaluated in the i-th genotype and j-th environment µ = the overall mean of the experiments B/E jk = the effect of k block within the j environment G i = the effect of the i-th genotype considered as fixed E j = the effect of the j-th environment considered as random GxE ij = the random effect of the interaction between i genotype and j environment e ijk = the random error associated with observation Y ijk Subsequently, the effect of genotypes and G x A interaction was unfolded at each site according to the partial diallel structure. Method 4 of Griffing (1956) adapted to partial diallel was adopted, which estimates the general (GCA) and specific (SCA) combining ability in partial diallel involving only F 1 s hybrids, according to the model below: (2) where: Y ij = the mean of the cross between the i-th line of Group I and the j-th line of Group II µ = the overall mean of the diallel; g i is the general combining ability of the i-th line of Group I g j = the general combining ability of the j-th line of Group II s ij = the specific combining ability of the lines of the Groups I and II e ij = the experimental error The GCA estimates of each group of lines and SCA estimates were plotted on a graph where the axes corresponded to the two sites analyzed.…”

“…Grain sorghum [Sorghum bicolor (L.) Moench] is the fifth most cultivated cereal in the world, being a critical caloric source for human feeding in developing countries and in feed formulation for poultry, pigs, and cattle. One of the significant advantages of this crop is its high photosynthetic efficiency and high tolerance to abiotic stresses, especially to drought (1,2,3,18). Grain sorghum tolerates and avoids drought better than many other cereal crops, like wheat and maize (1).…”