Late Season Water Stress in Cotton: I. Plant Growth, Water Use, and Yield

Abstract

The behavior of water stressed cotton (Gossypium hirsutum L.) is well documented, but our knowledge of traits which can be genetically manipulated to improve drought tolerance is incomplete. This study was conducted to determine which morphological and physiological factors lessen the effects of water stress on the yield of two short-season cultivars [i.e., TAMCOT HQg5 CHQg5) and G&P 74 ÷ (GP74)] with a common parent in ancestry. Plants were grown in a rain shelterlysimeter facility containing a Pedernales fine sandy loam soil (fine, mixed, thermic Udic Paleustalf) in 1990 and 1991 at Temple, TX. Water stress was imposed by replenishing a fraction of the water lost to evapotranspiration, beginning about 78 d after emergence. HQ95 and GP74 did not differ in leaf area index (LA]) or in the rate of leaf area development before water stress was imposed. The rate of LAI decline and average LAI were similar between cultivars when water stress was imposed. HQg5 used more water and used it at a faster rate than GP74 when water stressed. HQg5 produced more bolls and had higher yield under both well-watered and water stressed conditions than GP74 in each of the 2 yr. The largest difference in boll load between cultivars occurred on sympodia branches in the lower canopy, where HQ95 had 37, 60, and 182% more bolls than GP74 when plants received 0, 50 or 75, and 100% of the depleted soil water. Whether well watered or water stressed, individual boll weight did not differ between the two cultivars. However, the harvest index and the production efficiency of bolls (i.e., bossl pr unit leaf area) of HQ95 was consistently higher than GP74 for all water regimes. On average, HQ95 allocated 21% more dry matter to yield and produced 32% more bolls per square meter than GP74. While differences in yield between the cultivars mirror harvest index, large differences in boll production efficiency suggested that the intrinsic photosynthetic capacity of HQ95 may be greater than GP74. C OTa~ON is grown under a wide range of climatesfrom the humid sub-tropics of South Carolina to the semi-arid desert of California. Yet, water supply remains a critical limitation of yield. Genetic variation in yield and water-use efficiency has been reported for cotton subjected to water deficits (Quisenberry and McMichael, 1991; Cook and EI-Zik, 1993). Also, the effects of water deficits and relationships between cotton growth and water requirements are well documented (Grimes and EI-Zik, 1982; Morrow and Krieg, 1990). However, a fundamental understanding of the intrinsic factors which could improve the ability of cotton to withstand water deficits remains to be developed. We know that cotton fruit production and retention

Effects of Salt and Water Stress on Leaf Production, Sodium and Potassium Ion Accumulation in Soybean

“…The reduction in leaf area due to salinity was reported earlier by Khan et al [17] in rice and Chookhampaeng [6] in pepper plant. Drought stress reduces cell and leaf expansion, stem elongation, and leaf area index ( [34], [4], [10]). The reduction in leaf area was attributed due to the increasing in leaf senescence and reduced size of leaves developed due to low turgor under saline and water stress conditions.…”

Competition between drought-tolerant upland rice cultivars and weeds under water stress condition

“…According to Taiz & Zeiger (2004), limitation promoted in the leaf area can be considered one of the first responses of plants to water deficit. According to Gerik et al (1996), the balance between production of assimilates and demand for the development of the reproductive organs becomes severely affected by the reduction in the photosynthetically active leaf area.…”

Irrigation Timing and Rate Affect Cotton Boll Distribution and Fiber Quality

“…Many cotton irrigation studies have recognized the impacts of water deficit on cotton growth, yield, and fiber quality (Dağdelen et al, 2009;DeTar, 2008;Gerik et al, 1996;Howell et al, 2004;Peng et al, 1989;Pettigrew, 2004), and a considerable amount of research has been conducted on the effects of severe, moderate, and low water stress on cotton boll distribution and mass (Ritchie et al, 2009;Snowden et al, 2013;Yang and Zhou, 2010), but it is relatively unknown if equal or more efficient boll production results could be achieved with less irrigation applied at precise intervals. Another limitation of existing work is that there is not a defined response to the interaction between various periods of water stress on cotton production.…”