Preventing canopy mortality during drought is essential for efficient recovery in cotton

This study aimed to identify the underlying traits associated with drought avoidance, tolerance, and recovery capacity in high-yielding cotton, as well as to contribute to the selection of the best-fit variety for water-limited environments. Six commercial varieties utilized for cotton production in the United States were selected. Despite the large variability within each variety, differences in drought avoidance and tolerance were observed among varieties. The variety DP2127, which achieves the greatest lint production in the field, exhibited both low avoidance and low tolerance. The variety ST4990, which efficiently sustains lint production in the absence of irrigation in semi-arid sites, exhibited both high avoidance and high tolerance. Differences in drought avoidance across varieties could not be explained by leaf hydraulic traits or early declines in transpiration during drought. Differences in drought tolerance across varieties could not be explained by leaf embolism resistance. By analyzing the response of individual plants, rather than varieties, we could establish that (1) plants with lower canopy transpiration during well-watered conditions delayed dehydration and physiological dysfunction during drought and (2) lower canopy mortality during drought resulted in more efficient recovery post-drought. Our findings suggest that selecting cotton varieties that limit transpiration per leaf area, instead of varieties that trigger leaf shedding during drought, might result in greater avoidance and recovery in combination. Field-based studies are warranted to confirm the avoidance, tolerance, and recovery capacity for these six varieties and to determine how these strategies contribute to yield stability in cotton under water limitation.