Drought-Tolerant Corn Hybrids Yield More in Drought-Stressed Environments with No Penalty in Non-stressed Environments

Abstract

The potential benefit of drought-tolerant (DT) corn (Zea mays L.) hybrids may depend on drought intensity, duration, crop growth stage (timing), and the array of drought tolerance mechanisms present in selected hybrids. We hypothesized that corn hybrids containing DT traits would produce more consistent yields compared to non-DT hybrids in the presence of drought stress. The objective of this study was to define types of production environments where DT hybrids have a yield advantage compared to non-DT hybrids. Drought tolerant and non-DT hybrid pairs of similar maturity were planted in six site-years with different soil types, seasonal evapotranspiration (ET), and vapor pressure deficit (VPD), representing a range of macro-environments. Irrigation regimes and seeding rates were used to create several micro-environments within each macro-environment. Hybrid response to the range of macro and micro-environmental stresses were characterized in terms of water use efficiency, grain yield, and environmental index. Yield advantage of DT hybrids was positively correlated with environment ET and VPD. Drought tolerant hybrids yielded 5 to 7% more than non-DT hybrids in high and medium ET environments (>430 mm ET), corresponding to seasonal VPD greater than 1200 Pa. Environmental index analysis confirmed that DT hybrids were superior in stressful environments. Yield advantage for DT hybrids appeared as yield dropped below 10.8 Mg ha-1 and averaged as much as 0.6–1 Mg ha-1 at the low yield range. Hybrids with DT technology can offer a degree of buffering against drought stress by minimizing yield reduction, but also maintaining a comparable yield potential in high yielding environments. Further studies should focus on the physiological mechanisms presented in the commercially available corn drought tolerant hybrids.

Aerial canopy temperature differences between fast‐ and slow‐wilting soya bean genotypes

“…Crop breeders have made efforts to develop drought-tolerant crops such as corn (Zea mays L.), bread wheat (Triticum aestivum L.), cotton (Gossypium hirsutum L.), soya bean and rice (Oryza sativa L.) (Basal, Smith, Thaxton, & Hemphill, 2005;Bolanos & Edmeades, 1996;Dhanda, Sethi, & Behl, 2004;Sapra & Anaele, 1991;Sloane, Patterson, & Carter, 1990 ). Commercially available drought-tolerant corn hybrids were recently released by DuPont Pioneer (AQUAmax TM ), Syngenta (Artesian TM ) and Monsanto (DroughtGard TM ) (Adee, Roozeboom, Balboa, Schlegel, & Ciampitti, 2016). Among a range of environments differing in evaporative demand and drought, there was a yield advantage of AQUAmax and DroughtGard hybrids over the non-drought-tolerant hybrids that increased as drought severity increased, but there was no difference in yield between drought-tolerant and non-drought-tolerant hybrids in the absence of stress (Adee et al, 2016).…”

Classification of Crop Tolerance to Heat and Drought—A Deep Convolutional Neural Networks Approach

“…To classify 2,452 corn hybrids as either tolerant or susceptible to drought stress, heat stress, and combined drought and heat stress, we performed regression analysis on the yield of hybrids and extracted stress metrics. We conducted linear regression of yield of hybrid against each stress, and classified the hybrid based on the slope of the regression line, since the slope of the regression line indicates the yield adaptability of the hybrid (Adee et al, 2016). The intuition behind this approach is that if a hybrid is tolerant against a type of stress, then the slope of the regression line should be a positive value or a small negative value.…”

“…To improve the corn performance under environmental stresses, seed companies have started developing stress-tolerant corn hybrids to alleviate the negative effects of drought and heat stress. Drought-tolerant (DT) hybrids have been developed through traditional plant breeding such as Pioneer Optimum AQUAmax TM and Syngenta Artesian TM , which yielded 5% to 7% more than non-DT hybrids in high stress environments, while maintaining a comparable yield potential in high yielding environments (Adee et al, 2016). Chen et al (2012) identified some heat tolerant corn inbred lines that demonstrated an enhanced tolerance to elevated temperatures.…”

“…The slopes of the regression lines indicate the sensitivities of hybrid yield with respect to the stresses. Small slopes indicate tolerant hybrids, which have more stable yields across different environments, and large slopes indicate non-tolerant hybrids, which have less yield adaptability (Adee et al, 2016).…”

Contributions of biotechnology to meeting future food and environmental security needs

“…7% yield gains are obtained for these deregulated hybrid maize, which has also been approved for import to China since 2013, as MON7460. No performance penalty was found in non-stressed environments (58,59). The Genuity DroughtGard series of hybrids (60) also include combinations of stacked genes, including resistance to particular herbicides and potentially pests such as the European corn borer, for particular settings (61).…”