Cotton lint yield and quality variability in Georgia, USA: Understanding genotypic and environmental interactions

Cotton lint yield variability in a heterogeneous soil at a landscape scale

Regional cotton lint yield, ET c and water value in Arizona and California

Cotton acreage in the Coastal Plain of the Southeast has increased in recent years. The soils in this region are sandy and typically have a low retention capacity for sulfate S. A 3-yr (1993-1995) field test was conducted in south Alabama on a Lucy loamy sand (loamy, kaolinitic, thermic Arenic Kandiudults) to evaluate the response of cotton (Gossypium hirsutum L.) to the source, rate, and timing of S fertilizer applications. Sulfur was broadcast preplant as either ammonium sulfate, elemental S, potassium sulfate, potassium thiosulfate, or K-Mg-sulfate at rates of 0, 10, 20 and 40 lb S/acre. Additionally, ammonium sulfate was applied at first square to evaluate timing effects. Lint yields were increased each year and they peaked at a rate of approximately 20 lb S/acre on this Lucy Is soil. Averaged across sources, 20 lb S/acre increased lint yields by an average of 21% as compared with the no S check treatment. Lint yields were not affected by time of S application in 1993 or 1995, but a preplant application of S increased yield compared with S applied at first square in 1994. The response to time of S application was attributed to heavy rainfall that was received soon after the first square application of S. Sources of S did not affect lint yield in 1993 or 1995, but ammonium sulfate and K-Mg-sulfate produced slightly higher yields than those of other sources in 1994, an extremely wet growing season. Lint quality, as measured by high volume instrumentation (HVI), was not affected by any S treatment in 1993 or 1994. In 1995, fiber length increased with S rate, but the differences among sources were inconsistent. Results of this test suggest that cotton produced on sandy Coastal Plain soils that are low in S may require annual applications of 20 lb S/acre to ensure high yields. The S should be applied preplant, although delaying application to first square should not limit yields. For lint production, differences among commercial S fertilizer sources should be minimal.

The development of earlier maturing, cool temperature tolerant varieties of cotton (Gossypium hirsutum L.) has allowed cotton production to expand into regions with shorter, cooler growing seasons. The objective of this research was to evaluate the interactive effect of soil type, irrigation, and meteorological conditions on the water use and lint yield of cotton grown in four U.S. Great Plains soils. Cotton was grown in 2005 through 2007 in 48 weighing lysimeters which contained clay loam, silt loam, sandy loam, or fine sand at Bushland, TX, with irrigation beginning after emergence. The seasonal heat units (HU) from planting to harvest were 1010°C in 2005, 1075°C in 2006, and 985°C in 2007. From seedling to beginning boll development, reference evapotranspiration averaged 7.6 mm in 2005, 8.5 mm in 2006, and 6.7 mm in 2007. Lint yield was significantly related to open boll number at harvest in all soils and years. Averaged cotton lint yields for the 2005 and 2007 full and deficit irrigation treatments were significantly larger in the fine sand (160 g m−2) than in the other soils (126 g m−2). In 2006, cotton lint yield in the fine sand was significantly smaller (101 g m−2) than the average of the other soils (147 g m−2). Cotton lint yield increased in the silt loam soil and decreased in the fine sand as seasonal HU increased. Early season meteorological conditions which influenced square shedding and boll development may have affected lint yields interactively with soil texture and irrigation.

This study aimed to simulate the spatiotemporal variation in cotton (Gossypium hirsutum L.) growth and lint yield using a remote sensing-integrated crop model (RSCM) for cotton. The developed modeling scheme incorporated proximal sensing data and satellite imagery. We formulated this model and evaluated its accuracy using field datasets obtained in Lamesa in 1999, Halfway in 2002 and 2004, and Lubbock in 2003–2005 in the Texas High Plains in the USA. We found that RSCM cotton could reproduce the cotton leaf area index and lint yield across different locations and irrigation systems with a statistically significant degree of accuracy. RSCM cotton was also used to simulate cotton lint yield for the field circles in Halfway. The RSCM system could accurately reproduce the spatiotemporal variations in cotton lint yield when integrated with satellite images. From the results of this study, we predict that the proposed crop-modeling approach will be applicable for the practical monitoring of cotton growth and productivity by farmers. Furthermore, a user can operate the modeling system with minimal input data, owing to the integration of proximal and remote sensing information.

Grazing cover crops can improve land‐use efficiency and diversification, making agricultural enterprises more resilient to market fluctuations. We investigated how grazing intensity affects cover crop forage responses and cotton (Gossypium hirsutumL.) lint yield. Cover crops were a rye (Secale cerealeL.)–oat (Avena sativaL.) mixture managed as follows: no grazing + 34 kg N ha–1(NG34), no grazing + 90 kg N ha–1(NG90), heavy grazing (HG), moderate grazing (MG), and light grazing (LG), compared with a no cover crop control. All grazed treatments received 90 kg N ha–1. Average postgrazing herbage mass (HM) for HG, MG, and LG was 520, 1,350, and 2,120 kg dry matter ha–1, respectively. Herbage accumulation (HA) rate was greater for LG than HG, with MG being intermediate. Forage crude protein (CP) and in vitro digestible organic matter (IVDOM) concentrations decreased as the season progressed and were usually greater for HG than MG and LG. Stubble residue before cover crop termination was greatest for NG34 and NG90 in 2018 and 2020, however, in 2019 NG90 had greater stubble residue before termination than NG34 (7540 vs. 6650 kg dry matter ha–1). Heavy grazing resulted in greater weed proportion (17 vs. 6.5%) and lesser soil cover (49 vs. 70%) than nongrazed cover crops. Cotton lint yield was low and unaffected by treatment, reaching a maximum of 520 kg ha–1in 2019. Although lint yield was not affected by cover crop fertilization or grazing during 3 yr, HG reduced soil cover and increased weed presence.

Successful precision agriculture requires an understanding of spatial variability of soil properties, crop growth, and their interactions. The objectives of this study were 1) to examine the spatial variability of soil properties, cotton lint yield, and fiber quality and 2) to evaluate the spatial variability within mapping units at a production‐field scale. This research was conducted on an irrigated 49‐ha cotton field in Texas from 1998 through 2000. Samples were collected from regular 1‐ha grids, triangular, and random points. Results indicated that soil properties had stronger spatial dependence than did cotton lint yields and fiber quality. Soil properties, except nitrate (NO3 −) nitrogen (N) and Olsen phosphorus (P), were strongly spatially dependent, whereas lint yield was moderately to strongly spatially dependent. Fiber quality was moderately spatially dependent. Spatial appearance of higher yield in drier years was associated with the distribution of soil properties favoring cotton growth, including lower pH and calcium (Ca) and higher P and sand content. There were differences in the means and spatial structure parameters of the selected measurements among the three soil mapping units, suggesting the need for careful sampling design to make reasonable estimation of soil properties under a nonstationary situation. Furthermore, the spatial variability of soil properties and cotton yield were intensified under limited water supply, implying that site‐specific cotton management may be appropriate for cotton producers in the Texas high plains. Contribution of the College of Agricultural Sciences and Natural Resources at Texas Tech University Scientific J. Series Paper Number T‐4‐572.

The United States is experiencing longer crop growing season in most states, which could afford producers the opportunity to diversify into double‐cropping (DC) and cover crop systems rather than the predominant summer and winter fallow systems. Thus, this study evaluated DC and cover crops effects on wheat (Triticum aestivum L.), cotton (Gossypium hirsutum L.), and soybean (Glycine max) yield under conventional tillage (CT) and no‐tillage (NT). Summer cover crops (SCCs) were sunn hemp (Crotolaria juncea L.) and sorghum sudangrass (Sorghum bicolor), while winter cover crops (WCCs) were Austrian winter pea (Pisum sativum) and wheat. Cropping systems were wheat‐fallow (W‐F), wheat‐cotton (W‐C), wheat‐soybean (W‐S), W‐SCC, WCC‐C, F‐C, WCC‐S, and F‐S. Tillage effect on crop yields varied across years. In 2021, wheat yield in CT of W‐C, W‐F, and W‐SCC (2831, 2689, and 2646 kg ha−1) significantly differed from NT of W‐S (1720 kg ha−1). No significant tillage effect was observed on cotton lint yield between W‐C and WCC‐C. For soybean, in 2020, the CT of W‐S and WCC‐S significantly outyielded the NT of W‐S and WCC‐S. Cropping system effect on wheat yield between W‐S and W‐SCC (1419 and 1987 kg ha−1) was significant in 2020 due to low stand counts in W‐SCC arising from the thick SCC biomass. Cotton lint yield in WCC‐C outyielded W‐C in all 3 years but was not significant. Soybean grain yield in W‐S was consistently higher than in WCC‐S, though not significant. Cotton lint and soybean grain yield in the fallow systems were the least. Overall, in a short term, crop yield in DC and cover crop systems were similar.

There have been conflicting results reported about the effect on cotton (Gossypium spp.) lint yield of altering planting and irrigation termination (IT) timing. The objectives of this study were to identify a planting window (PW), on a heat unit (HU) basis, and IT timing, as a function of crop growth stage, for optimum yield potential of Upland (G. hirsutum L.) and American Pima (G. babadense L.) cotton. Two PWs of Upland 'Deltapine 90' (DPL 90), Pima 'S-6', and IT treatments were included in field experiments for 11 site-years. Planting windows were defined as PW1 and PW2 for plantings prior to and following 600 HU accumulated after 1 January, respectively. Two IT treatments were imposed for each planting. Irrigation termination in the desert Southwest generally results in cessation of growth (crop termination). The first IT treatment (IT1), was imposed to ensure full development of bolls set up to cutout, and the second (IT2) was after two additional irrigations. From covariate analysis, there was no evidence of interaction between PW and IT, indicating that these treatments responded the same across the different environments for both cotton species. There were, however, differences in lint yields among treatments. For DPL 90, PW1 IT2 yielded 83 and 97 Ib/acre more than PW1 IT1 and PW2 IT2; and for Pima S-6, PW1 IT2 was 118 and 204 Ib/acre more than PW1 IT1 and PW2 IT2, respectively. Early planting is necessary for optimum yield potential of full-season cotton varieties; with the greatest yield coming from early planting and termination after the development of a second fruiting cycle (PW1 IT2). However, if a reduction in input costs and the avoidance of late-season insect pests are important considerations then cotton should be planted early (300 to 600 HU after 1 Jan) and terminated at the end of the first fruiting cycle (approximately 600 HU past cutout) to maintain the lint yield potential of full-season maturity types of Upland and Pima cotton.

Cotton (Gossypium hirsutum L.) lint yields have not changed appreciably during the last decade. Because more and higher infestations of reniform nematodes (Rotylenchulus reniformis) have been identified in mid‐southern USA fields, this nematode might be a mitigating factor in the cotton yield stagnation. The objectives were to determine how varying rates of K fertilization interacted with different cotton genotypes to influence dry matter partitioning, lint yield, fiber quality, and reniform nematode populations. Nine cotton genotypes were grown in the field under two levels of K fertilization (0 and 112 kg K ha−1) and two levels of aldicarb [2‐methyl‐2‐(methylthio)propionaldehyde 0‐methylcarbamoyloxime] application (0 and 1.68 kg a.i. ha−1) from 1999 through 2001. Reniform nematode numbers and aboveground dry matter partitioning were determined at various times in the growing season. Lint yield, yield components, and fiber quality were determined at the end of the season. Cotton grown with K fertilization hosted a 12% larger post‐harvest population of reniform nematode than the unfertilized control plants. Plants grown without K fertilization averaged a 10% greater specific leaf weight than the K fertilized plants. Of the 9 genotypes grown, only PayMaster 1218BR increased lint yield (10%) in response to K fertilization. An interaction between aldicarb application and K fertilization for lint yield during the 2000 growing season indicated that both reniform nematode parasitism and insufficient K fertilization may impose limitations to lint yield production. Large reinform nematode populations may be suppressing the yield response to K fertilization. Production practices that encourage robust plant growth may enhance proliferation of existing reniform nematode populations.

Cotton (Gossypium hirsutumL.) lint yield responds well to increasing rates of poultry litter fertilization, but little is known of how optimum rates for yield compare with optimum rates for profit. The objectives of this study were to analyze cotton lint yield response to poultry litter application rates, determine and compare rates that maximize lint yield (PLy) vs. profit (PLp), and identify a practical approach for estimating PLp. Cotton planted on two farms that used conventional and no‐tillage systems were fertilized with seven target rates of litter from 0 to 13.5 Mg ha−1or with a farm standard treatment receiving synthetic fertilizers (Std). The PLyand PLpfor each year and farm were determined from current cotton and poultry litter prices and response curves fitted into lint yield and actual applied litter rates. The results showed that cotton lint yield peaked at an average across years of 1430 kg ha−1, with 11.1 Mg ha−1PLyin the conventional tillage system and at 1354 kg ha−1with 13.2 Mg ha−1PLyin the no‐till system. These peak yields exceeded the respective Std treatment yields but were not the most profitable. Maximum profit in both tillage systems was achieved with 7.8 Mg ha−1PLp, which resulted in lint yields of 1367 and 1253 kg ha−1in the conventional and no‐till systems, respectively. The PLpin both systems was similar to the poultry litter rate that resulted in lint yield equal to the Std (PLs), which suggests that applying litter to provide plant available N equal to the farm standard practice for synthetic N fertilizers is a practical method for estimating PLp.

Many cotton growers sow rotation crops after irrigated cotton (Gossypium hirsutum L.), assuming that they will improve soil quality and maintain profitability of cotton. Wheat (Triticum aestivum L.) is the most common rotation crop, although more recently, legumes such as faba bean (Vicia Faba L.) and chickpea (Cicer arietinum L.) have come into favour. This paper reports data on soil quality (organic C, nitrate-N, soil structure), yield (cotton lint and rotation crop grain yield, fibre quality), economic returns (gross margins/ha, gross margins/ML irrigation water), and management constraints from an experiment conducted from 1993 to 1998 near Wee Waa, north-western New South Wales, Australia. The soil is a medium-fine, self-mulching, grey Vertosol. The cropping sequences used were cotton followed by N-fertilised wheat (urea at 140 kg N/ha in 1993; 120 kg N/ha thereafter), unfertilised wheat, and unfertilised grain legumes (chickpea in 1993; faba bean thereafter), which were either harvested or the grain incorporated during land preparation. Soil organic C in the 0—0.6 m depth was not affected by the rotation crop, although variations occurred between times of sampling. Regression analysis indicated that there had been no net gain or loss of organic C between June 1993 and October 1998. Sowing leguminous rotation crops increased nitrate-N values. A net increase in root-zone nitrate-N reserves occurred with time (from June 1993 to October 1998) with all rotation crops. Soil compaction (measured as specific volume of oven-dried soil) was lower with wheat by October 1998. A net decrease in soil compaction occurred in the surface 0.15 m with all rotation crops between 1993 and 1998, whereas it increased in the 0.15–0.60 m depth. Cotton lint yield and quality, and gross margins/ha and gross margins/ML, were always higher where wheat was sown, with highest gross margins occurring when N fertiliser was applied. Applying N fertiliser to wheat did not significantly increase cotton lint yield and fibre quality, but increased gross margins of the cotton–wheat sequence due to higher wheat yield and protein percentage. Lint yield and fibre quality were decreased by sowing leguminous rotation crops. Management constraints such as lack of effective herbicides, insect damage, harvesting damage, and availability of suitable marketing options were greater with legumes than with wheat. Overall, wheat was a better rotation crop than grain legumes for irrigated cotton.

Field experiments were conducted in Hale Co., TX, in 2005 and 2006 to determine the effects of 2,4-D amine and dicamba applied at varying rates and growth stages on cotton growth and yield, and to correlate cotton injury levels and lint yield reductions. Dicamba or 2,4-D amine was applied at four growth stages including cotyledon to two-leaf, four- to five-leaf, pinhead square, and early bloom. Dicamba and 2,4-D amine were applied at 1/2, 1/20, 1/200, and 1/2000 of the recommended use rate. Crop injury was recorded at 14 days after treatments and late-season, and cotton lint yields were determined. Across all growth stages, 2,4-D caused more crop injury and yield loss than dicamba. Cotton lint was reduced more by later applications (especially pinhead square) and injury underestimated yield loss with 2,4-D. Visual estimates of injury overestimated yield loss when 2,4-D or dicamba was applied early (cotyledon to two leaf) and was not a good predictor of yield loss.

Accurate estimates of cotton (Gossypium hirsutum) dry matter accumulation and nitrogen content are important for both production and environmental reasons. One of the important factors in estimate accuracy is sample size. The objective of this investigation was to determine the cotton sample size necessary for acceptable estimates of cotton dry matter, lint yield, and shoot N per 100 kg of lint ratio (NLR) values. Three cotton cultivars (DeltaPine 90, DeltaPine 5415, and Stoneville 474) were planted on 13 May 1997 in an Eunola loamy sand (fine‐loamy, siliceous, thermic Aquic Hapludult) in 9.3‐m2 subplots of a split‐split plot design. Split plots were four sampling dates. Split‐split plots were four sampling techniques [a) four randomly selected plants (4RP), b) 0.3 meter of row (0.3‐m), c) one meter of row (1‐m), and d) two meters of row (2‐m)]. Each entire subplot was harvested on each sampling date after sampling by the four techniques. Shoot dry matter for the whole plot was 7.2 Mg ha‐1, and lint yield was 1.46 Mg ha‐1. Cotton shoot dry matter and NLRs were significantly overestimated by both the 4RP and 0.3‐m techniques, but not by the 1‐ and 2‐m techniques. The NLRs of cultivar subplots varied with cultivar from 9.1 to 11.4. The earliest maturing cultivar, DeltaPine 90, had the lowest NLR and the latest maturing cultivar, Stoneville 474, had the highest NLR. Accurate estimates of cotton dry matter accumulation and N content will likely require 1‐m samples, and 2‐m samples should further improve precision. The NLRs were similar to data (NLR <15) that suggest 1.6 Mg ha‐1 (3‐bale/acre) cotton lint yields can be achieved with less than 250 kg ha‐1 of shoot‐accumulated N.

ABSTRACTWinter cereals are often used as cover crops before planting cotton (Gossypium hirsutum L.). Black oat (Avena strigosa Schreb.) is the predominate cereal cover crop for cash crops in southern Brazil and Paraguay, but limited information is available on the suitability of black oat as a cover crop in the southeastern USA. The objectives of this study were to compare black oat with adapted winter cereals for this region and to determine the effect of cereal residue species and amount on cotton growth, N status, and lint yield. In a greenhouse study in which black oat and rye (Secale cereale L.) residues were mixed with soil, tap root elongation of both cotton and radish (Raphanus sativa L.) was inhibited more by black oat residue than by rye residue. In a field experiment on a Goldsboro loamy sand (fine‐loamy, siliceous, thermic Aquic Kandiudult), cotton was grown in 1995 and 1996 following black oat, oat (Avena sativa L.), rye, and wheat (Triticum aestivum L.) that were planted at three different times (October, November, and December). All four winter cereals had similar biomass production at each planting date in 1995. In 1996, rye was the only species not visibly damaged by a low temperature of −12.2°C that occurred during the winter. Black oat biomass was comparable to wheat in all planting dates but averaged 60% less than rye over all three planting dates and was 37% less than oat in the October planting date in that year. Black oat tended to have a higher N concentration than the other cereal species. Cotton plant density was lowest following black oat and rye. Cotton growth, leaf blade N, and petiole NO3‐N were more dependent on residue amount than on residue species. Cotton lint yield following black oat was 120 kg ha−1 higher than lint yield of cotton following rye. Cotton following black oat, wheat, and oat had similar lint yield. Black oat may be a promising cover crop for the southeastern USA, but evaluations of other cultivars and/or improvement programs to improve cold hardiness are needed to improve the utility of this species.