Derek P. Whitelock

Cotton (Gossypium spp.) is the world’s most important fiber crop for the textile industry. Drought stress can adversely affect cotton production and quality, particularly in arid and semi-arid regions. Biochar, produced from biomass through pyrolysis, has the potential to alleviate drought stress in cotton production through improving soil properties and enhancing plant nutrition. The objectives of this study were to evaluate the effects of biochar produced from southern yellow pine (Pinus spp.) on cotton seedling emergence and growth, yield and its component traits, and fiber quality traits under field drought-stressed, arid conditions in the U.S. over two years. Six genotypes were evaluated in 2024, and three of these genotypes were evaluated following a single application of biochar at four rates (0, 6.25, 12.5, and 25.0 t ha⁻¹) applied at the beginning of the study. Significant genotypic differences were observed in both years, as expected. No genotype × biochar interaction was detected, indicating that different cotton genotypes responded similarly to biochar application. Groundcherry (Physalis acutifolia) infestation was unexpectedly higher, and cotton seedling growth was reduced in the biochar-amended plots compared with the non-biochar control in 2024, but these effects were not observed in 2025. Plots amended with 12.5 and 25.0 t ha⁻¹ biochar had significantly higher soil moisture than those receiving 0 or 6.25 t ha⁻¹ biochar. Estimated seedcotton yield was the highest in plots receiving 12.5 t ha⁻¹ biochar in both years and was significantly greater than that of the non-biochar control, with 18.3 and 8.4% increases in 2024 and 2025, respectively. Biochar had no significant effects on fiber length, uniformity, strength, elongation, and micronaire in either year, except that 6.25 and 12.5 t ha⁻¹ biochar rates increased elongation and 25.0 t ha⁻¹ biochar rate decreased micronaire. These results indicate a single biochar application had a positive, although diminishing, effect of biochar on cotton productivity during the first two years under drought stress, while having little to no effects on fiber quality.

Upland cotton is an important fiber and oilseed crop. Cottonseed size, measured by seed index, is an important seed quality trait that affects seed germination, seedling vigor, fiber yield, and cottonseed nutrient content. However, genetic variation in cottonseed size is highly limited within upland cotton, limiting the genetic gain in cottonseed size. Introgression breeding can alleviate this bottleneck effect by introducing desirable genes from pima to upland cotton. This study was conducted to analyze the seed size from both fuzzy and acid-delinted seeds and to assess the appropriate cottonseed size. In 2022, a population of 1600 cotton introgression lines (ILs) was grown at Leyendecker Plant Science Center, NMSU, while three field tests were conducted in 2023, including NM with all the ILs and MS and TX each with 1000 ILs. The analysis of variance of seed size showed that genotypic and environmental variation were found in both types of seeds. The acid-delinted and fuzzy cottonseeds had a mean seed index of 9.58 g and 11.26 g, while the broad sense heritability was 0.56 and 0.32, respectively. Furthermore, the seed index was not significantly correlated with cottonseed oil and different fatty acids.

Research is needed to improve walnut drying throughput and energy consumption in hulling plants, but current methods for sampling nuts in commercial drying bins and measuring nut moisture content limit the capacity to investigate the drying process thoroughly. A novel apparatus for obtaining walnut samples at multiple depths and locations in stadium drying bins and a novel rapid method for accurately determining walnut in-shell moisture content were developed. A second rapid moisture measurement method involving near-infrared light (NIR) was also investigated. The sampling apparatus consisted of three sampling columns installed in each walnut drying bin. Each column had gate valves at four elevations, admitting approximately 30 in-shell walnuts to rectangular buckets hanging on a cable just below each gate valve. To collect samples, the gates were opened and closed, the buckets were withdrawn, the nut samples were collected and sealed in labeled bags, and then the buckets were returned to the column to be ready for the next sampling interval. This configuration, sampling nuts at four levels across three locations in the drying bin, allowed better moisture content variability investigation during in-bin walnut drying. The rapid moisture content measurement method consisted of selecting twelve representative in-shell walnuts from each sample and grinding them in a mill. Twelve grams were sub-sampled from the well-mixed ground material and dried in an oven at 105 ± 1 °C for 3 h, then reweighed to determine moisture loss. The coefficient of variation for sub-samples within an individual sample (n = 4) averaged 2.65% for moisture contents ranging from 6% to 47% dry basis. The rapid moisture content measurement method reduced the drying time from 24 h to 3 h compared to conventional oven drying method, with an accuracy of ±0.5 to 1.5% of the full moisture content range. The best correlation observed between the NIR methodology and the rapid moisture content method was 0.74 R². These new in-bin walnut sampling and moisture-content measurement methods will accelerate future research aimed at improving walnut drying at commercial huller facilities.

Cotton (Gossypium spp.) is the most important fiber crop for the textile industry globally. Abiotic stresses, including drought, have become prevalent in affecting cotton production worldwide. There is a shortage of studies on the use of biochar as a soil amendment in the semi-arid and arid Southwest and West U.S. Cotton Belt to alleviate drought stress. This study was conducted to examine the effects of biochar at four application rates (0, 6.25, 12.5, and 25.0 t ha⁻¹) on cotton yield and yield components using six tetraploid cotton genotypes, including one Pima (G. barbadense L.) and five Upland cottons (G. hirsutum L.), under well-watered (WW) and drought stress (DS) conditions in an arid region of New Mexico, USA. The six cotton genotypes consistently showed that DS at the flowering stage significantly decreased boll number (BN), boll weight (BW), and lint percentage (LP), and thereby seed cotton weight (SCW) per plant and lint weight (LW) per plant. However, Pima DP 359 RF had the lowest reduction (23–33%) in BN, SCW, and LW due to drought, while DP 2020 B3XF was the most sensitive to drought, with a 45–48% reduction in the traits. Under DS conditions, biochar at the rate of 12.5 t ha⁻¹ had the highest SCW and LW, and the lowest reduction in BN, BW, SCW, and LW due to drought, which was significantly different from the non-biochar control, and no genotype × biochar interaction was detected. However, biochar had no positive effects on cotton productivity under non-drought conditions. This study has demonstrated the positive effects of biochar on cotton yield and yield components in alleviating drought stress, laying the foundation for more follow-up studies toward its utility in cotton production in semi-arid and arid areas.

Current saw- and pin-type lint-cleaning systems used by the ginning industry have challenges retaining lint quality. The objective of the research was to test a novel pneumatic fractionator for the lint cleaning of an Upland cotton variety that was both saw- and roller-ginned. The process variables tested were initial lint moisture content in the range of 5.5–15% w.b., line pressure in the range of 276–552 kPa, and residence time in the range of 15–45 s. Experiments were conducted based on a central composite design. Models based on response surface methodology (RSM) were developed for final lint moisture, total trash extracted during lint cleaning, and High-Volume Instrument (HVI) fiber quality. The RSM models adequately described the pneumatic fractionation process, as indicated by the coefficient of determination, predicted vs. observed plots, and residual values. The results indicated that the interactions among initial lint moisture content, residence time, and line pressure significantly affected lint quality. At the optimized pneumatic fractionator process conditions, the predicted lint quality attributes were better for both roller- and saw-ginned lint compared to lint cleaned with saw- and pin-type lint cleaners. The upper half mean length increased by 1 mm, the uniformity index was higher by 0.5–1 percentage points, the strength was 1–2 g/tex higher, and the short fiber content was reduced by more than one percentage point. Color grades were better for pneumatic fractionated lint compared to saw- and pin-type lint cleaning methods. Lint value was approximately 4 cents/kg higher for both saw- and roller-ginned pneumatic fractionated lint, compared to lint cleaned using saw- and pin-type lint cleaners. The novel pneumatic fractionator, when compared to industry-standard saw- and pin-type lint cleaners, effectively cleaned lint while retaining fiber quality and removing most of the motes and trash.

Highlights Walnut dust is listed as combustible by OSHA. This designation could trigger requirements for walnut hullers and shellers to install expensive sprinkler systems and approved dust control systems. Recognized standard combustible dust screening tests showed that walnut huller and sheller dusts were not flammable solids and should not be considered combustible. Abstract. Fires and explosions at agricultural facilities have been an issue across the world. While some agricultural industries like sugar and grain handling facilities have had issues with fires or explosions and have been subject to regulations on dusts for many years, many other agricultural processors have not. The U.S. Occupational Safety and Health Administration (OSHA) lists walnut dust as combustible. Some local governments and insurance companies have attempted to apply that designation to dust at walnut huller and sheller facilities. Facilities that generate potentially combustible dusts must abide by National Fire Protection Association standards that require expensive sprinkler systems and approved dust control systems and may have difficulties obtaining approval for building permits and insurance coverage. Tests following United Nations Manual of Tests and Criteria, Part III, Subsection 33.2.1, Test N.1, “Test Method for Flammable Solids” were conducted to determine the combustibility of dust samples collected at walnut hulling and shelling facilities in California. According to these tests following the UN method, the walnut huller and sheller dusts were not flammable solids and therefore should not be considered combustible dusts. Keywords: Combustible, Flammable, Huller, Sheller, Walnut dust.

Developing cotton ginning methods that improve fiber length uniformity index to levels that are compatible with newer and more efficient spinning technologies would expand market share and increase the demand for cotton products and give U.S. cotton a competitive edge to synthetic fibers. Older studies on lint cleaning machines showed that the most widely used feed mechanism that places fiber on the cleaning cylinder damages the fiber and reduces uniformity. The present study evaluates how conventional and experimental feed mechanisms affect uniformity. The lint cleaners were used with both saw and roller gin stands. Four diverse cotton cultivars from the Far West, Southwest, and Mid-South were used in the test. Statistical analysis used a random effects modeling approach which included constructing a 95% confidence interval for each ginning treatment around the predicted mean for the fiber property of interest, and then examining which treatments overlap (for comparison). Results show that the micro-saw gin with the direct-feed lint cleaner had the best uniformity at 85.8%. Prior research has shown that roller ginning is consistently higher in uniformity than any type of saw ginning. In this study, the roller ginning treatments had uniformities of 85.3 and 85.6%, so it is encouraging that the saw gin stand with the direct-feed lint cleaner had very high uniformity. This suggests that it may be beneficial to place fiber directly onto the lint cleaning saw without changing direction. Additionally, the saw gin-coupled lint cleaner had a uniformity of 84.3% which is also a respectable level of uniformity. These results indicate that the direct-feed lint cleaner and coupled lint cleaner warrant further testing under better controlled conditions.

In the present study, two high-capacity experimental roller gin reclaimers, (a) a modified 3-saw cylinder stick machine (three-saw) and (b) a modified 2-saw cylinder gin stand feeder (700), were optimized with respect to reclaimer saw cylinder speed and carryover/seed ratio to minimize the seed and lint loss for both Pima and Upland cotton varieties and were compared to a conventional roller gin reclaimer operated by the ginning industry under standard conditions. Developed regression models adequately described the seed and lint loss phenomena during the reclaiming process. Surface plots indicated that the reclaimer saw cylinder speed and carryover/seed ratio impacted the seed and lint loss for both the 3-saw and 700 reclaimers. Under optimized conditions, the 700 reclaimer resulted in lower lint and seed loss compared to the 3-saw reclaimer when using Upland cotton. In the case of Pima cotton, under optimized conditions, the 3-saw reclaimer had 38% lower lint loss and 24% higher seed loss compared to the 700 reclaimer. The regression equations of both 3-saw and 700 reclaimers were further used to optimize the reclaimers in parallel arrangement to minimize the seed and lint loss. With Upland cotton, the economic loss was about 2.5 times greater with the conventional reclaimer compared to the 3-saw and 700 reclaimers ($15.97/bale loss for the conventional, $8.63 for the 3-saw, and $6.44 for the 700 reclaimers). With Pima cotton, the conventional reclaimer resulted in a lower economic loss ($3.44/bale) compared to the 700 reclaimer which had a loss of about $3.59/bale.