Fiber Properties and Carbohydrate and Nitrogen Levels of Cotton Plants as Influenced by Moisture Supply and Fruitfulness

Abstract

As distinct from the cereal crops and the spring-flowering fruits, which are characterized by a reproductive climax, cotton is like the tomato and cucurbits in its indeterminate growth; but it is different in the minor extent to which fruit size is influenced by environment and fruitfulness. In a regional variety study (3), 16 varieties of cotton planted during each of three years at eight locations showed locational variations in the varietal means of only 8%c in fiber length, 6%c in fiber weight-per-inch and 9%0 in fiber strength. In terms of use value, however, such differences have high significance. The tendency toward uniformity in the bolls of cotton is accounted for by the extent to which young bolls are shed as the plant becomes heavily fruited. Within varieties and environments, the number of developing bolls per unit of vegetative weight (11) has been found to be remarkably uniform.From California irrigation experiments, ADAMS et al.(1) record that reductions in water supply result generally in losses in staple length (usually within 1/32 inch), seed index (usually within 1.0 gram) and lint index (usually within 0.5 gram). Drought has been observed to decrease the length of cotton lint (2, 5, 18); with this effect, an increase in fiber strength was usually found. BERKLEY et al. (4), as well as others, have associated the increased strength of fibers with a narrowing of the angle of the cellulose crystallites (x-ray angles).Increased nitrogen supply has been found to result in some increase in length of fiber (7,16,19). On the other hand, little effect upon length was found by STURKIE (18), whereas, in the presence of inadequate supplies of some other elements, BROWN (6) reported length reductions to result from nitrogenous fertilizers. As has been the general experience with other plants, WADLEIGH (19) found increased nitrogen supply to result in lower carbohydrate accumulations. He associated as causal the plus and minus changes in carbohydrate or nitrogen with the changes in boll properties and in fiber length that corresponded in sign.CROWTHER (7) and NELSON (16) have shown phosphate to increase boll size but not to alter fiber properties. Nelson also found that potash additions which greatly increased yield also increased fiber length and weight per inch; the x-ray angles were increased and the strength of fiber and yarn decreased. YOUNGE (20) has shown sulphur deficiency that reduced boll production had little effect on fiber properties.

Effects of Shade and Partial Defoliation on Carbohydrate Levels and the Growth, Fruiting and Fiber Properties of Cotton Plants.

“…(3,12,13,14,16,19). Considerable work has been done on other seeds and grains (2,4,6,15), but relatively little has been done on maize or corn. Bailey (1) found respiration of corn to be less affect-ed by moisture than that of wheat with the materials he used.…”

Environmental Effects on Cotton Fiber Carbohydrate Concentration and Quality

“…Micronaire was also reduced when night temperatures were lower than 25°C (Gipson and Joham, 1968). Moisture deficits have been reported to reduce fiber lengths (Bennett et al, 1967; Eaton and Ergle, 1952, 1954; Marani and Amirav, 1971), but the moisture stress needs to be severe and occur shortly after flowering for there to be a significant reduction of the fiber length (Marani and Amirav, 1971). Drought stress can also reduce fiber micronaire (Eaton and Ergle, 1952; Marani and Amirav, 1971), but this effect is probably due to reductions in the photosynthetic capacity of the canopy.…”

“…Moisture deficits have been reported to reduce fiber lengths (Bennett et al, 1967; Eaton and Ergle, 1952, 1954; Marani and Amirav, 1971), but the moisture stress needs to be severe and occur shortly after flowering for there to be a significant reduction of the fiber length (Marani and Amirav, 1971). Drought stress can also reduce fiber micronaire (Eaton and Ergle, 1952; Marani and Amirav, 1971), but this effect is probably due to reductions in the photosynthetic capacity of the canopy. This hypothesis is further supported by evidence from shading studies where a 30% shade treatment reduced the micronaire (Pettigrew, 1995, 1996) and a 70% shade treatment reduced fiber maturity, a component of micronaire (Eaton and Ergle, 1954).…”

Source‐to‐Sink Manipulation Effects on Cotton Fiber Quality

“…Moisture deficit stress appeared to reduce fiber length (Bennett et al, 1967;Ergle, 1952, 1954;Marani and Amirav, 1971), although Marani and Amirav (1971) reported that the moisture stress needed to be severe and to occur shortly after flowering for the length to be significantly reduced. A severe drought stress can also reduce fiber micronaire (Eaton and Ergle, 1952;Marani and Amirav, 1971). The only report relating irradiance to fiber quality is from Eaton and Ergle (1954) who, using a nonreplicated data set, observed lower fibe; strength and maturity but increased fiber length due to a 70% shade treatment.…”