Water-deficit resilience by early initiation of transpiration decrease with soil drying: case studies of peanut genetics and maize response to triple super phosphate

Abstract

Background and aims Soil water deficits develop at some point during many cropping seasons. To enhance crop drought resilience, cropping characteristics to conserve soil water have often proved desirable. In this paper, two case studies are presented that documented from discovery through to field evaluation the characteristic of initiation of decrease in transpiration rate at comparatively high soil water contents for drought resilience. These case studies are on peanut genetic selection and maize triple super phosphate management. Methods Initiation of transpiration rate decrease at a high soil water content during soil drying was studied using multiple-stage screening. In both case studies water conservation was examined in both controlled and field environments, including the initiation of field yield trials. Results The study with peanut involved screening many genotypes for delayed leaf wilting and for transpiration response to soil drying. Genotype N12006ol expressed the water conservation characteristic and was found to have greater yield productivity under dryland conditions than a common commercial cultivar. The study with maize investigated crop water conservation induced by application of triple super phosphate to soil. Preliminary field trial in three states in the United States indicated a possible yield advantage from triple super phosphate in locations that suffered water-deficit conditions. Conclusion Both the genetic study with peanut and the phosphorus study with maize showed under controlled conditions the expression of soil water conservation by initiation of transpiration rate decrease at high soil water content. Field trials offered supportive evidence that this water conservation characteristic under water-deficit conditions resulted in increased probability of greater crop yields.

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