Foliar spraying of plant growth regulators can alleviate high-temperature stress in late-sown spring potatoes to improve yield and quality

Abstract

In practice, late sowing of spring potatoes is commonly adopted to bridge crop rotation and mitigate natural disasters, inadvertently facilitating high-temperature conditions during the latter growth phase, leading to diminished tuber yield and quality. To avert these setbacks, this experiment explored the influence foliar applications of plant growth regulators like Diethyl aminoethyl hexanoate (DTA-6), Uniconazole (S3307), Abscisic acid (S-ABA), and Salicylic acid (SA) on Zhongshu Zao 45 (ZZ45), a late-sowing tolerant variety, and Yunshu 902 (Y902), a sensitive variety. The findings indicated that spraying growth regulators can effectively upgrade the agronomic attributes of late-sown spring potatoes: They curbed the above-ground part of growth, boosted the root-top ratio, promoted dry matter accumulation in the below-ground part, and regulated leaf area index. Physiologically, they increased leaf SPAD value and net photosynthetic rate, reduced MDA and proline content, ultimately increasing yield and improving quality. In the case of the late sowing tolerant variety Zhongshu Zao45 and sensitive variety Yunshu902, S-ABA and S3307 respectively produced the most effective results. A further investigation discovered that S-ABA and S3307 both pitch in endogenous hormone regulation, augmenting antioxidant enzyme activity to bolster plant resilience and alleviate adversity stress from late-sown high temperatures. By selecting appropriate growth regulators for different varieties, it is possible to achieve stable yield and improved quality for late-sown spring potatoes. This study furnishes theoretical insights into the field production of late-sown potatoes.