Multiple Irrigation Levels Affect Boll Distribution, Yield, and Fiber Micronaire in Cotton

Abstract

or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. U pland cotton is a crop with an indeterminate fruiting habit that is influenced by the environment in which the plant grows. Effective flowering (flowering on fruiting sites that contribute to economic yield) begins about 60 d after the crop is planted and continues for about 4 to 6 wk (Bruns, 2009), depending on cultivar and environmental conditions. Flower production begins at the bottom of the cotton plant (usually between mainstem nodes 5 and 7) and flowers are formed on adjacent nodes up the plant every 2 to 3 d, and on adjacent sympodial positions every 4 to 6 d (Bednarz and Nichols, 2005). This indeterminate fruiting habit also allows the crop to compensate for temporary unfavorable conditions (Bednarz and Nichols, 2005;Pettigrew, 1995) by replacing bolls lost early in the season by producing additional fruiting sites on other parts of the plant later in the season. Cotton yield has been described as the product of environmental conditions, genetic background, and management practices, including plant density, plant growth regulator management, insect pressure, and irrigation management. An analysis of within-plant boll distribution known as plant mapping is a method of plant measurement that has been used to quantify the effects of the variables described above on boll production and retention.Jenkins et al. (1990) observed that cultivar maturity characteristics and irrigation rate can both affect boll production and retention. Although a long flowering and fruiting interval can allow cotton plants to recover from transient stresses, this characteristic also means that when a cotton plant undergoes stress, it must partition its limited carbohydrate resources to ensure maximized fruit production. Bednarz and Nichols (2005) and Jenkins et al. (1990) found that earlier maturing cultivars produced a greater percentage of their total lint yields at lower main stem nodes than later maturing cultivars, and that early maturing cultivars also respond to stress differently than later maturing cultivars. Early-fruiting cultivars retain more fruit lower in the plant, while later-fruiting cultivars tend to produce additional fruit in the upper portions of the plant (Pettigrew, 2004). Bednarz and Nichols (2005) stated that in regions with long growing season, such as Georgia and South Texas, later maturing cultivars may produce more stable yields and recover from exposure to brief periods of drought more successfully than earlier maturing cultivars. In these locations, cotton plants can accumulate more than 1400 growing degree days (GDD 15.6 ). However, in regions with shorter growing seasons, like the northern Texas Panhandle, plants are often limited by environments where there are fewer than 1150 GDD 15.6 (Howell et al., 2004). In a short-season environment, the shift of boll production to higher nodes may be detrimental to later maturing cultivars, AbstrACtThe boll...

Cotton Response to Water Deficits at Different Growth Stages

“…Several studies have been conducted, showing that prolonged water deficit during the cotton cultivation cycle affects growth, productivity, and quality of the fibers (SNOWDEN et al, 2013;ZONTA et al, 2015a, ZONTA et al, 2015b.…”

Cotton Maturity Determination through Vertical Mapping

“…A comparison of vertical and horizontal flowering intervals for this study suggested that, even though flowering intervals are decreased, the two-node delay from first to second sympodial position was still a general pattern among all cultivars (Fig. It has been shown that the fraction of first-position fruit depends on cultivar, planting density, irrigation, fertility, insect pressure, and other influences (Kerby et al, 1986;Reddy et al, 1992;Pettigrew, 2004;Siebert and Stewart, 2006;Snowden et al, 2013). It has been shown that the fraction of first-position fruit depends on cultivar, planting density, irrigation, fertility, insect pressure, and other influences (Kerby et al, 1986;Reddy et al, 1992;Pettigrew, 2004;Siebert and Stewart, 2006;Snowden et al, 2013).…”

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.…”

“…Reduced levels of irrigation early in the growing season may have fewer adverse effects than during flowering (Snowden et al, 2013). However, previous work has focused on an all-ornothing approach during periods of water deficit stress.…”