Source‐to‐Sink Manipulation Effects on Cotton Fiber Quality

Abstract

Cotton (Gossypium hirsutum L.) fiber quality varies considerably among years and locations depending on the prevailing environmental conditions. These environmental conditions often affect the assimilate source/reproductive sink ratio of the developing crop. This study investigated the effects of various source‐sink manipulations on cotton fiber quality at various times during the growing season. In 1991 and 1992, field studies were conducted in which six source‐sink manipulation treatments (partial defruited, partial leaf pruned, reflectors, open canopy, shaded plot, and an untreated control) were imposed on the cotton genotypes ‘DES 119’, ‘DPL 5690’, and ‘Prema’. Blooms at anthesis were tagged on four dates each year, and the seed cotton was harvested when these bolls had opened. This seed cotton was then ginned, and fiber quality traits were determined. The shaded plot treatment reduced fiber strength 6% compared with the control. Fiber from the shaded plot treatment was about 2% longer than the control when the shade was applied within the first 7 d of fiber development. The micronaire value was decreased 7% from the control when the shade was applied during the period of fiber development when the fiber secondary cell wall is being deposited. The partial defruited treatment consistently produced about 8% greater micronaire than the control. Fiber from the partial leaf pruned and shaded plot treatment (low source‐to‐sink ratio) averaged 11% lower micronaire than the open canopy and partial defruited treatment (high source‐to‐sink ratio) on the first tagging date. On the third tagging date, fiber maturity, a component of micronaire, for the partial defruited treatment was 6% greater than the control. None of the treatments significantly altered fiber elongation or perimeter. These data indicate that alterations in the light intensity or carbon assimilate supply can affect the quality of cotton fiber produced, particularly fiber strength and micronaire.

Transgenic cotton over-producing spinach sucrose phosphate synthase showed enhanced leaf sucrose synthesis and improved fiber quality under controlled environmental conditions

“…The resulting immature fibers have lower cellulose content, industrial utility, and yield (Gipson 1986;Haigler et al 2005). Low light leading to reduced CO 2 fixation can also limit cotton fiber yield and quality (Pettigrew 1994), which is consistent with the strong carbon sink represented by the fiber secondary walls.…”

Effects of Fertilizer and Time of Ridge-Tie on Yield and Fibre Quality of Late Sown Cotton in the Dry Savanna Zone of Nigeria

“…Ridge tied at 6 WAP also resulted in a lower micronaire value in the two years of fibre quality study. Micronaire is an estimate of secondary wall deposition (Pettigrew, 1995) and the amount of secondary wall deposition determines fibre fineness and maturity. Results here revealed that the 60 kg N ha Ϫ1 recommended for early sown cotton in the dry savanna (Enwezor et al, 1989) may not be appropriate for late sown cotton.…”

Irrigation Timing and Rate Affect Cotton Boll Distribution and Fiber Quality

“…Conversely, the lowest micronaire values were apparent when there were high or med levels of irrigation in P2, followed by low ITL in P3. These findings indicate the complexity of the interaction between micronaire, irrigation, and environment; there are several studies in which micronaire decreased in response to additional irrigation at the end of the season (Heitholt, 1997;Heitholt and Schmidt, 1994;Pettigrew, 1995). However, because micronaire is related to both fiber development and the maturation process, any factor that inhibits development and maturation, whether additional water or water deficit, can result in changes in fiber thickness and maturity.…”

“…Episodic loss of irrigation water is not always remedied with full irrigation afterward (Snowden et al, 2014). The indeterminate fruiting pattern of cotton may allow the crop to produce additional fruiting sites on other parts of the plant later in the season to replace bolls that were lost early on in the season due to temporary unfavorable conditions (Bednarz and Nichols, 2005;Pettigrew, 1995). One traditional strategy to combat yield loss due to mid-season water deficit stress has been to apply irrigation prior to planting or early in the growing season to try to build up water resources in the soil profile to supplement rainfall and irrigation during vital crop growth stages (Mahan et al, 2012).…”