Highest Cotton Yield Research Articles

Effects of Irrigation Amount and Nitrogen Rate on Cotton Yield, Nitrogen Use Efficiency, and Soil Nitrogen Balance under Drip Irrigation

Water and nitrogen (N) are major constraints for cotton growth and yield formation in arid regions. Irrigation and N application have been widely investigated to improve crop yield and water and N use efficiency (NUE). However, further optimization of water and N management is needed because the effects of N application on soil N balance and N loss under different irrigation levels remain unclear. In this study, a field experiment was conducted in 2020 and 2021 to investigate the effects of different irrigation amounts (full irrigation (100% ETc), moderate irrigation (80% ETc), low irrigation (60% ETc)) and N application rates (control (without N application, N0), low N (150 kg ha−1, N150), medium N (225 kg ha−1 and 300 kg ha−1, N225 and N300), and high N (375 kg ha−1, N375)) on cotton yield, NUE, and soil N balance. The 2-year results showed that under the 60% ETc treatment, cotton dry matter accumulation, N uptake, and yield were significantly enhanced by increasing N application. Under the 80% and 100% ETc treatments, these parameters peaked with the N300 treatment; the N375 treatment showed no significant difference or decrease compared to the N300 treatment. The 80% ETc N300 treatment had the highest cotton yield and NUE, which increased by 17.49–106.57% and 12.28–88.78% compared with other treatments, respectively. Residual soil N accumulation (RSNmin), apparent N loss (ANL), and apparent N surplus (ANS) increased as the N application rate increased under the 60% and 100% ETc treatments. While under the 80% ETc treatment, the ANS did not significantly differ between the N225 and N300 treatments, ANL significantly decreased by 43.51–88.56% when the N application rate increased from 150 to 225 and 300 kg ha−1. The ANL of the 80% ETc N300 treatment was the lowest, but ANS did not significantly increase. The regression analysis and spatial analysis results showed that under irrigation of 336–348 mm and N application of 254–327 kg ha−1, cotton yield, NUE, and WPI reached more than 80% of the maximum value, with less apparent N loss, thus maintaining the soil N balance in drip-irrigated cotton fields. This study helps to improve the utilization of water and N resources in cotton production. Future research on optimizing water and N management needs to more fully consider environmental pollution to achieve sustainable development of agricultural ecosystems.

Effects of Drip Irrigation Flow Rate and Layout Designs on Soil Salt Leaching and Cotton Growth under Limited Irrigation

Optimal drip irrigation management in shallow groundwater areas needs to clarify the effects of flow rate and layout designs on the soil moisture, salt distribution, cotton root length density, plant height, leaf area, and yield. In this study, a one-year field experiment was conducted from April to October 2018 in the fifth company of the 16th Regiment in Alar City, Xinjiang, to investigate the effects of various drip flow rates and layout designs of cotton growth. Two drip flow rates (2.8 and 5.6 L·h−1) and two layout designs (one film, two drip tapes, and six rows; one film, three drip tapes, and six rows) were applied to explore the optimal combination, resulting in a total of four treatments that were irrigated three times in the whole growth period. Soil moisture, salt distribution, cotton root length density, plant height, and leaf area were measured. The main results were as follows: (1) Under the same layout designs, the soil moisture content was higher and the soil salinity was lower when the drip flow rate was 5.6 L·h−1, and the cotton root length density, plant height, leaf area, and yield were significantly higher than that of 2.8 L·h−1. (2) Under the same drip flow rate, the soil desalination rate, cotton growth indexes, and yield under the three-tapes treatment were significantly higher than the values of the two-tapes treatment. The actual yield of treatment D was 21.56%, 19.23%, and 11.71% higher than that of treatments A, B, and C, respectively. (3) The crop evapotranspiration of cotton during the two irrigation cycles showed an increasing trend, and the groundwater contribution showed a smaller and then increasing trend. Overall, the combination of three tapes and a drip flow rate of 5.6 L·h−1 had the highest cotton yield and net income, which were 6211.36 kg·hm−2 and 4820.21 kg·hm−2 for the theoretical and actual yields. The results of this study can provide a reference for the management of limited irrigation leaching soil salinity and cotton cultivation in shallow groundwater areas.

Combining ability of Egyptian cotton (Gossypium barbadense L.) reveals genetic potential for improved yield and fiber quality

BackgroundAs the most widely cultivated fiber crop, cotton production depends on hybridization to unlock the yield potential of current varieties. A deep understanding of genetic dissection is crucial for the cultivation of enhanced hybrid plants with desired traits, such as high yield and fine fiber quality. In this study, the general combining ability (GCA) and specific combining ability (SCA) of yield and fiber quality of nine cotton parents (six lines and three testers) and eighteen F1 crosses produced using a line × tester mating design were analyzed.ResultsThe results revealed significant effects of genotypes, parents, crosses, and interactions between parents and crosses for most of the studied traits. Moreover, the effects of both additive and non-additive gene actions played a notably significant role in the inheritance of most of the yield and fiber quality attributes. The F1 hybrids of (Giza 90 × Aust) × Giza 86, Uzbekistan 1 × Giza 97, and Giza 96 × Giza 97 demonstrated superior performance due to their favorable integration of high yield attributes and premium fiber quality characteristics. Path analysis revealed that lint yield has the highest positive direct effect on seed cotton yield, while lint percentage showed the highest negative direct effect on seed cotton yield. Principal component analysis identified specific parents and hybrids associated with higher cotton yield, fiber quality, and other agronomic traits.ConclusionThis study provides insights into identifying potential single- and three-way cross hybrids with superior cotton yield and fiber quality characteristics, laying a foundation for future research on improving fiber quality in cotton.

Impact of “Dry Sowing and Wet Emergence” Water Regulation on Physiological Growth Characteristics and Water Productivity of Cotton Fields in Southern Xinjiang Province

Determining a suitable “dry sowing and wet emergence” water control program for cotton fields in the arid regions of Northwest China is of great significance in saving water resources, improving economic efficiency, and promoting sustainable development of agriculture. The objective of this study was to analyze the effects of different “dry sowing and wet emergence” water control treatments on dry matter accumulation, chlorophyll fluorescence, yield quality, and water productivity of cotton, and to determine the optimal “dry sowing and wet emergence” water control program for cotton growth in arid areas. A two-year experiment was carried out in 2021 and 2022 in mulched drip-irrigated cotton fields, with a total of 13 treatments of different seedling water quantities (2021: 67.5 mm, 90 mm, 112.5 mm; 2022: 6 mm, 10.5 mm, 15 mm) and different drip frequencies (frequencies means number of drops at seedling stage) (2021: one, two, three times; 2022: two times, four times) in the “dry sowing and wet emergence”. Results indicated a positive correlation between increased seedling water quantity and growth indexes. High seedling water quantity treatment demonstrated a 14.33% higher cotton yield than the low seedling water quantity treatment. In comparison with low-frequency treatment, the high-frequency treatment exhibited significantly larger cotton plant height, dry matter accumulation, and yield. Over two years, the average values increased by 8.69%, 16.4%, and 15.91%, respectively, with a 14.55% increase in the coefficient of photochemical quenching of the leaf blade (qP). The high frequency and larger amount of seedling water quantity treatments showed significantly higher irrigation water productivity, with increases of 39.2% and 70.2% compared to the winter irrigation control treatment. In summary, the appropriate “dry sowing wet emergence” water regulation mode (the first drip: 15 mm, the second drip: 4.5 mm, the third drip: 22.5 mm, the fourth drip: 15 mm) can ensure crop yield quality under the premise of significantly reducing the agricultural irrigation water, which can provide certain theoretical support for the green, efficient, and sustainable development of the local cotton industry.

Comparative bio-efficacy of different insecticides on major sucking pests of Bt-cotton

The field evaluation of various insecticides on major sucking pests of Bt-cotton during the 2022-23 season demonstrated significant reductions in pest occurrence across all treatments compared to the control. However, the efficacy varied depending on the insecticide used. Among all the treatments, Flonicamid 50 WG proved highly effective in managing all the sucking pests by recording lowest incidence of thrips (8.44/ 3 leaves), leaf hopper (5.43/ 3 leaves), aphid (3.64/ 3 leaves) and whitefly (3.29/ 3 leaves) with highest cotton yield (19.41 q/ha), net returns (53,540 `/ha) and B: C ratio (1.85) as compared to all other treatments. In addition, other promising alternatives such as Dinotefuran 20 SG, Spinetoram 11.7 SC, and Diafenthiuron 50 WP for combating thrips, Dinotefuran 20 SG and Spinetoram 11.7 SC for addressing leaf hoppers, and Pyriproxyfen 10 EC, Diafenthiuron 50 WP, and Dinotefuran 20 SG can be utilized for managing aphids and whiteflies in Bt- cotton. Utilizing these findings to optimize the selection and application of insecticides can enable growers to more effectively control pest pressures, thereby enhancing both the productivity and quality of Bt-cotton crops. Overall, Flonicamid 50 WG emerged as the most cost-effective option, underscoring its potential as a key solution for managing sucking pests in Bt-cotton cultivation.

Genetics of biochemical attributes regulating morpho-physiology of upland cotton under high temperature conditions

BackgroundCotton is a strategically important fibre crop for global textile industry. It profoundly impacts several countries' industrial and agricultural sectors. Sustainable cotton production is continuously threatened by the unpredictable changes in climate, specifically high temperatures. Breeding heat-tolerant, high-yielding cotton cultivars with wide adaptability to be grown in the regions with rising temperatures is one of the primary objectives of modern cotton breeding programmes. Therefore, the main objective of the current study is to figure out the effective breeding approach to imparting heat tolerance as well as the judicious utilization of commercially significant and stress-tolerant attributes in cotton breeding. Initially, the two most notable heat-susceptible (FH-115 and NIAB Kiran) and tolerant (IUB-13 and GH-Mubarak) cotton cultivars were spotted to develop filial and backcross populations to accomplish the preceding study objectives. The heat tolerant cultivars were screened on the basis of various morphological (seed cotton yield per plant, ginning turnout percentage), physiological (pollen viability, cell membrane thermostability) and biochemical (peroxidase activity, proline content, hydrogen peroxide content) parameters.ResultsThe results clearly exhibited that heat stress consequently had a detrimental impact on every studied plant trait, as revealed by the ability of crossing and their backcross populations to tolerate high temperatures. However, when considering overall yield, biochemical, and physiological traits, the IUB-13 × FH-115 cross went over particularly well at both normal and high temperature conditions. Moreover, overall seed cotton yield per plant exhibited a positive correlation with both pollen viability and antioxidant levels (POD activity and proline content).ConclusionsSelection from segregation population and criteria involving pollen viability and antioxidant levels concluded to be an effective strategy for the screening of heat-tolerant cotton germplasms. Therefore, understanding acquired from this study can assist breeders identifying traits that should be prioritized in order to develop climate resilient cotton cultivars.

Cotton irrigation regime under the mole irrigation method in the south of Russia

Studies on developing optimal soil water regimes under mole irrigation of cotton compared with sprinkling and drip irrigation were conducted in 2023 on light-chestnut soils of southern Russia. As a result, it was found that under mole irrigation, with increasing the pre-watering threshold of soil moisture from 70-70-65 to 80-80-75 % of the lowest water holding capacity (LWC) irrigation rates decreased from 250...290 to 170...210 m3/ha and the number of irrigations and irrigation rate increased from 4 to 7 units and from 1040 to 1270 m3/ha. A comparison of irrigation methods showed that under mole irrigation, in comparison with drip irrigation, irrigation rates increased by 7.4. 13.3 %, and the number of irrigations per season and irrigation rate decreased by 1...2 units and 11.2...12.6 %, respectively. Compared to sprinkling, irrigation rates and total amount of water decreased by 45.2...46.3 and 28.8...34.5 %, respectively, and the number of irrigations increased by 1 unit. It was also found that maintaining a moisture availability level of 75-75-70 % LWC created optimal conditions in cotton crops, which, combined with mineral fertilizer application with doses N140P60K45, allowed the highest cotton yield under mole irrigation of 3.18 t/ha. When sprinkling on a similar option, it decreased by 0.21 t/ha, and at drip irrigation, it increased by 0.13 t/ha.

El algodón y su respuesta a diferentes condiciones hídricas del suelo

Introduction: One of the biggest problems in cotton farming in the Comarca Lagunera, Mexico, is the low efficiency of irrigation, since the large quantities of water used for this crop result in water shortages. Objectives: To determine the response function of the cotton crop to different soil moisture contents, as well as the water use efficiency. Methodology: Seven treatments were evaluated in the field: 40-40, 40-80, 60-60, 60-100, 80-40, 80-80 and 100-60 % of available moisture consumed (AMC) by the cotton plant at two phenological stages. Treatments were distributed in a randomized block design with four replications. Results: The highest cotton yield (8.7 Mg∙ha-1) was obtained with the treatment that developed under 63 and 62 % AMC at the first and second stages of development, respectively, by consuming 97 cm of water. Limitation of the study: The models do not predict satisfactorily when extrapolating outside the range of moisture levels considered in the study. Originality: No studies have been reported on extreme favorable and unfavorable conditions of soil moisture content in cotton to know its productive response. Conclusions: The obtained model maximizes cotton production (8.74 Mg∙ha-1) with a water deficit of 59 and 56 % AMC. The highest water productivity (0.945 kg∙m-3) was obtained with 81 and 82 % AMC and 78 cm of water consumption.

Influence of soil water regime on cotton yield under mole irrigation in southern Russia

Studies on the features of mole irrigation of cotton were conducted at Volgograd State Agrarian University in 2023 on light-chestnut soils of southern Russia. One of the central tasks of our research was to determine the influence of soil water regime on cotton yield under mole irrigation compared with sprinkling and drip irrigation. As a result, it was found that the main component of the cotton soil water regime was the irrigation rate (more than 50 %). Its value at an increase of pre-watering soil moisture from 70-70-65 to 80-80-75 % LWC under mole irrigation increased from 1040 to 1270 m3/ha. As a result, total water consumption increased from 2175 to 2332 m3/ha, which, compared with sprinkling and drip irrigation, was less by 430...673 and 146...245 m3/ha, respectively. It was also found that the highest cotton yields were obtained when moisture availability was maintained at 75-75-70% LWC. Among irrigation methods, at mole irrigation on this variant, the yield occupied an intermediate position of 1.87...3.18 t/ha; at sprinkling, it decreased by 0.04...0.21 t/ha, and at drip irrigation, it increased by 0.10. 0.18 t/ha.

Ecological plasticity and sustainability of cotton in the Southern Steppe of Ukraine

Depending on the length of the cotton growing season, the area of cultivation and its highest productivity potential are determined, and the prompt ripening of raw cotton allows for home-grown harvesting and high-quality soil preparation. The purpose of this study was to identify samples adapted to the conditions of the Southern Steppe of Ukraine from the cotton gene pool. The study used methods of plant variety expertise: phenological observations, morphological studies, and evaluation of breeding material for valuable traits. Based on the study results, parental components were selected to expand the process of forming early-ripening forms and productivity of raw cotton. The ability of cotton plants to grow in extreme conditions of the Southern Steppe of Ukraine was assessed and its homogeneity or stability, the index of growing conditions, the coefficient of variation – the difference in the numerical values of the trait duration of the period “germination – beginning of flowering” of plants in varieties with different growing season and their fluctuations around the average value were determined. It was found that according to the determined plasticity (bi), the variance of stability (Si2), and the coefficient of variation of the duration of “germination – the beginning of flowering” higher tolerance to environmental factors was characterised by ultra-early ripening varieties. The average regression coefficient (bi ) was -0.36; the variation in the duration of the period by year was 10.1%, which is significantly lower compared to early-ripening varieties – -0.77% and 12.9%, mid-ripening varieties – -0.80% and 15.0%, and late-ripening varieties – -1.30% and 16.6%, respectively. The maximum average productivity to frosty raw cotton of 49.4 g/plant was formed by the sample Pidozerskyi 4 (UF0800003), the duration of the period “germination – beginning of flowering” was 47 days, and “germination – full ripening” – <103 days. The lowest raw cotton productivity of 21.2 g/plant was demonstrated by the late-ripening sample Joloten 32 (IU14056549) of Turkmen selection, the duration of the growing season of which was 145 days on average over the years of research. The findings of this study will be used in further breeding to create high-yielding cotton varieties with increased environmental plasticity and stability and highquality fibre

CottonSense: A high-throughput field phenotyping system for cotton fruit segmentation and enumeration on edge devices

High-throughput phenotyping (HTP) has become a powerful tool for gaining insights into the genetic and environmental factors that affect cotton (Gossypium spp.) growth and yield. With the recent advances in the field of computer vision, namely the integration of deep learning algorithms, the accuracy and efficiency of HTP systems have improved dramatically, enabling them to automatically quantify such fundamental phenotypic traits as fruit identification and enumeration. However, there is currently no HTP system available for counting all the reproductive phases of cotton crop that can be deployed in agronomic field conditions throughout the growing season. This study presents CottonSense, an advanced HTP system that overcomes the challenges of deployment across multiple growth periods by effectively segmenting and enumerating cotton fruits at four stages of growth, including square, flower, closed boll, and open boll. Consequently, CottonSense enhances agronomic management through increased opportunities for data collection and analysis. Using RGB-D cameras, it captures and processes both two and three-dimensional data, facilitating a wider range of phenotypic trait extractions such as crop biomass and plant architecture. To segment the cotton fruits, a Mask-RCNN model is trained and optimized for faster inference using TensorRT. The model yields an average AP score of 79% in segmentation across the four fruit categories. Moreover, the model's accuracy in estimating total fruit count per image is validated by a strong agreement with the counts given by ten domain experts, as reflected by an R2 value of 0.94. Furthermore, to accurately count the segmented fruits over large populations of plants, an enumeration algorithm based on a tracking strategy is developed that achieves an R2 value of 0.93 when compared to hand-counted fruits in the field. The proposed HTP system, which is implemented entirely on an edge computing device, is cost-effective and power-efficient, making it an effective tool for high-yield cotton breeding and crop improvement. The code for CottonSense is publicly available at https://github.com/FeriBolour/CottonSense.

The synergistic effects of soil-applied boron and foliar-applied silicon on cotton fiber quality and yield

Studies of boron (B) and silicon (Si) synergy in cotton crops have shown promising results; however, the focus was on the foliar application of B and Si. Nonetheless, B is an element with little mobility in the plant and its best form of application is in the soil. Thus, the objective of this study was to evaluate the synergistic effect of soil applied B and foliar applied sSi on fiber quality and crop yield of cotton. For this purpose, a field experiment was carried out using cotton cultivar FM 985 GLTP. The soil’s B in the experimental site is classified as low for cotton cultivation. The experiment was conducted in a randomized complete-block design, in a 3 × 2 factorial scheme, with three doses of B: 0.0 kg ha−1 (deficiency), 2.0 kg ha−1 (recommended dose), and 4.0 kg ha−1 (high dose) in the absence and presence (920 g L−1) of Si, with four replications. One week after the 4th application of Si, B and Si leaf content was determined. At boll opening, crop yield was estimated, and fiber quality analysis was realized. Boron deficiency reduced cotton yield, in 11 and 9%, compared to the application of 2 and 4 kg ha−1 of B, respectively. The presence of Si, however, increased plant yield in 5% in the treatments with 0 and 2 kg ha−1 of B, respectively. Cotton fiber length and elongation were not influenced by the B doses and Si presence. Fiber breaking strength was increased in 5% by the presence of Si and was not influenced by B deficiency. Micronaire was 8% smaller in the treatment with 0 kg ha−1 of B and 6% smaller in the absence of Si. Short fiber index was 4% greater in the plants of the treatment with 0 kg ha−1 of B. The results of this study reports that the complementation with Si via foliar application increases fiber quality by enhance breaking strength and micronaire. In conclusion, the interaction between soil-applied B and foliar-applied Si is beneficial for cotton cultivation, resulting in high cotton yield with better fiber quality.

SYNTHESIS OF A DOUBLE COMPOUND BASED ON DIMETHYLOL UREA AND PHYTOCOMPOUND OF MOLYBDENUM AND THE STUDY OF ITS INFLUENCE ON THE POPULATION OF SOME SOIL MICROORGANISMS AND ACCUMULATION OF NITROGEN

Drillers used for agricultural crops, in particular cotton seeds, cannot provide additional nitrogen feeding in the required volume during a shortage of nitrogen fertilizers. This article sets the task of creating a new active substance based on the phyto compound dimethylolure and molybdenum, which allows you to reduce cotton diseases in cotton cultivation, increase the accumulation of light hydrolyzed nitrogen in the soil and obtain a high cotton yield. The purpose. Study of chemical interactions in a three-component aqueous-salt system of dimethylolure-molybdenum phyto-compound-water by isothermal method. Objects. DMM, FSMo, double compound DMM is the active reactant of FSMo. Results.The isothermal method at a temperature of 25°C found that in the concentration range of solutions of 12.2-9.8% DMM and 2.8-5.4% FSMo, DMM crystallizes in the system, at a concentration range of 5.7-2.1% DMM and 12.3-15.5% FSMo, FSMo crystallizes, and in the concentration range of 8.2 -6.4% DMM and 6.2-9.3% FSMo, the compound DMM•FSMo is separated from the solution into this phase.Conclusion. The chemical interaction in the water-salt system dimethylol urea (DMM) - molybdenum phytocompound (FSMo) - water was studied by isothermal methods of chemical analysis. The region of crystallization of a new double compound, an active substance based on DMM and FSMo, was established at a molar ratio of 4DMM•FSMo. On model soil samples, it was determined that the active substance - the double compound 4DMM•FSMo against the background of ammonium nitrate, in comparison with ammonium nitrate, increases the number of nitrogen-fixing bacteria by 3.0 and 3.2 times.

Effect of nitrogen application on nitrogen leaching pattern and leaching loss from drip irrigated cotton fields in Southern Xinjiang

Farmers provided excessive nitrogen fertilizer to obtain high cotton yield in Xinjiang, Northwest China. Although drip irrigation could save water resources and improve nitrogen use efficiency, it is not known if leaching is occurring or not and whether leaching will harm the water environment under different nitrogen application. The purpose of our study was to estimate the effect of different nitrogen (N) application on the N leaching loss in drip irrigated cotton fields in South Xinjiang. A field experiment was conducted with N application rates of 317(N317), 395(N395) and 476(N476) kg hm−2 from 2021 to 2022. The characteristics of N pattern and leaching amount were analyzed. The concentration of NO3- and total nitrogen in the leaching water significantly decreased with the decrease of N application. The proportion of NO3–to total nitrogen reached the highest values of 51.52%–58.16%, 49.53%–56.91%, and 57.52%–62.87% at bud, flower, and boll stages of cotton, respectively. Moreover, the proportion of NO3– to total nitrogen remained at a stable level, which indicated that NO3–was the main pattern of N leaching. The N loss in the treatment N395 and N317 was 79.67% and 67.48% of that in the N476 treatment (1.23 kg hm−2), while the yield was 120.56% and 112.46% of that in the N476 treatment. Compared with conventional fertilizer application (476 kg hm−2), the reasonable N fertilizer application would not only reduce the amount of N leaching, but also increase the cotton yield.

INHERITANCE OF MORPHO-ECONOMIC TRAITS AND COMBINING ABILITY ANALYSIS IN INTRASPECIFIC HYBRIDS OF GOSSYPIUM BARBADENSE L.

In intraspecific F1 diallel hybrids of Gossypium barbadense L., the inheritance study of traits plant height, boll weight, plant productivity, and 1000-seed weight, with combining ability analysis took place in 2020–2022 at the Institute of Genetics and Plant Experimental Biology, Academy of Sciences, Uzbekistan. These polygenic traits’ inheritance showed different ways in the fine-fiber cotton F1 hybrids. The plant height trait’s inheritance with overdominance and intermediate level of the high/low-performance cultivars. The boll weight trait was mainly in negative overdominance with incomplete dominance of the low-performance cultivar. The inheritance of seed cotton yield had the positive overdominance main control, while the 1000-seed weight had negative and positive overdominance. According to combining ability analysis, the highest positive general combining ability effects resulted in fine-fiber cotton cultivars Surkhan-14 (ĝi = 8.71) and Bo'ston (ĝi =1.86) for plant height, Guzor (ĝi = 0.12) for boll weight, in genotypes Marvarid (ĝi = 2.44) and Surkhan-14 (ĝi = 2.95) for plant productivity, and in cultivars Marvarid (ĝi = 2.3) and Guzor (ĝi = 2.8) for 1000-seed weight. The F1 hybrids Guzor × Surkhan-14, Marvarid × Bo'ston, and Bo'ston × Surkhan-14 showed the highest positive and desirable specific combining ability effects for 1000-seed weight and seed cotton yield. Results concluded that fine-fiber cotton cultivars Marvarid, Surkhan-14, and Guzor can benefit as initial breeding material in selecting high-yielding cotton cultivars.

Controlled Drainage Mediates Cotton Yield at Reduced Nitrogen Rates by Improving Soil Nitrogen and Water Contents

Controlled drainage (CD) can reduce outflow and improve soil productivity, whereas its impacts on soil nitrogen (N), moisture contents, and cotton (Gossypium hirsutum L.) yield at reduced N rates remain largely unknown. To address the question, a field experiment was conducted to investigate the effects of N fertilizer rates (280, 252, 224, and 196 kg N ha−1, designated N1, N0.9, N0.8, and N0.7, respectively) on soil moisture, nitrate N (NO3−–N), and ammonium N (NH4+–N) contents and yield of cotton under CD and free drainage (FD). Compared to FD, CD increased the soil moisture, NO3−–N, and NH4+–N contents in the 0–40 cm soil depths, leading to greater plant N uptake at each N rate. The decreased total N loss through runoff due to CD accounting for the enhanced soil N contents. Moreover, CD had greater soil NO3−–N content at the reduced N treatments, contributing to the enhanced plant N accumulation, number of bolls, and lint percentage, and thus obtains a relatively high cotton yield. Remarkably, cotton yield reduced significantly with the decrease in N rates under FD, but it was comparable between N1 and N0.9 or N0.8 under CD. These suggested that CD helps to maintain high soil N and moisture contents in the 0–40 cm soil depths at 10–20% reductions in N fertilizer rate and thus without compromising cotton yield. The results also provide scientific basis for drainage water management mediates cotton yield at reduced N fertilizer rates.

Mitigating Osmotic Stress and Enhancing Developmental Productivity Processes in Cotton through Integrative Use of Vermicompost and Cyanobacteria.

There is an urgent demand for biostimulant amendments that can sustainably alleviate osmotic stress. However, limited information is available about the integrated application of vermicompost and a cyanobacteria extract on cotton plants. In 2020 and 2021, two field experiments were carried out in which twelve combinations of three irrigation intervals were employed every 14 days (Irrig.14), 21 days (Irrig.21), and 28 days (Irrig.28) along with four amendment treatments (a control, vermicompost, cyanobacteria extract, and combination of vermicompost + cyanobacteria extract) in salt-affected soil. The integrative use of vermicompost and a cyanobacteria extract resulted in an observed improvement in the physicochemical attributes; non-enzymatic antioxidants (free amino acids, proline, total soluble sugars, and phenolics); and antioxidant enzyme activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) and a decrease in the levels of oxidative damage indicators (H2O2 and MDA). Significant augmentation in the content of chlorophyll a and b, carotenoid concentration, relative water content, stomatal conductance, and K+ was also observed. In conjunction with these findings, noticeable decreases in the content of Na+ and hydrogen peroxide (H2O2) and the degree of lipid peroxidation (MDA) proved the efficacy of this technique. Consequently, the highest cotton yield and productivity as well as fiber quality were achieved when vermicompost and a cyanobacteria extract were used together under increasing irrigation intervals in salt-affected soil. In conclusion, the integrated application of vermicompost and a cyanobacteria extract can be helpful for obtaining higher cotton productivity and fiber quality compared with the studied control and the individual applications of the vermicompost or the cyanobacteria extract under increasing irrigation intervals within salt-affected soil. Additionally, it can also help alleviate the harmful impact of these abiotic stresses.

COTTON ADVANCED LINES ASSESSMENT IN THE SOUTHERN REGION OF KAZAKHSTAN

The Turkestan region is a cotton-growing zone in South Kazakhstan, but also the northernmost cotton-growing area in the world. Annually, medium-staple cotton (Gossypium hirsutum L.) cultivation occurs on 115,000–125,000 ha, with 80,000–85,000 ha grown in the Districts of Maktaaral and Zhetysay, Kazakhstan. This region is highly susceptible to salinity, drought, invasion of dangerous pests (cotton budworm, beet borer, spider mites, and aphids), and diseases (fusarium blight [wilt] and gummosis). An extremely high salt content and aridity in the arable soil are the main limiting factors of that region, hence, genotype selection through genetic principles is the most effective and economical way to reduce their negative impacts on vegetation. Therefore, the research on developing resistant cotton cultivars suitable for such soil and climatic conditions is most relevant. Considering the above situation, assessment of newly developed high-yielding cotton cultivars with fiber quality of types III–IV for tolerance to heat and drought, salinization, and pests and diseases ensued during 2019, 2020, and 2021 at the Agricultural Experimental Station of Cotton and Melon Growing, Atakent, Kazakhstan. Their promising cotton genotypes resulted from strains developed through intraspecific and interspecific diallel hybridization. The newly developed eight cotton cultivars, grown on more than 92% of the hectarage in the Southern region of Kazakhstan, are PA-3031, PA-3044, M-4005, M-4007, M-4011, Bereke-07, Myrzashol-80, and M-4017.

Effects of irrigation regime on soil hydrothermal microenvironment, cotton biomass, and yield under non-film drip irrigation system in cotton fields in southern Xinjiang, China

Non-film drip irrigation cotton planting mode can effectively solve the problem of residual film pollution in arid areas and promote sustainable agricultural development. However, the research on the efficient irrigation regime and soil hydrothermal microenvironment suitable for non-film drip irrigation cotton planting is scarce. Considering this, using the data monitoring technology based on internet of things sensors, we set 3 different irrigation treatments in 2020–2021. In the flowering and boll setting stage, cotton was watered for 4 times (W4), 6 times (W6), and 8 times (W8) with a single irrigation amount of 69 mm for each of these 3 treatments, and the last time irrigation amount under W8 treatment was 52.2 mm. At the seedling stage, the cotton was not irrigated under each treatment. At the squaring stage, the irrigation times and single irrigation amount were the same under each treatment. The results showed that the average soil water content (SWC) in the 50–110 cm soil layer was increased obviously with the increase in the total irrigation amount. Compared with W4 and W8 treatments, W6 treatment exhibited the highest the soil temperature in the 10–30 cm soil layer in the full boll stage and boll opening stage and the highest soil effective accumulated temperature (SEAT) from initial flowering stage to boll opening stage. The reproductive organ allocation rate in two years was 3.6 % and 2 % higher under W6 than under W8, respectively. With the increase of total irrigation amount, the cotton yield was increased, but the irrigation water use efficiency (IWUE) was decreased. The highest cotton yield was achieved under W8 treatment, but it was not significantly different from that under W6 treatment, while IWUE was significantly lower under W8 than under W6. The effective air temperature (EAT) had the greatest positive impact on the average effective soil temperature (EST) in 10–50 cm soil layer, while the cumulative irrigation amount (CIA) had a negative impact on average EST in 10–50 cm soil layer. Evapotranspiration (ET) and SEAT were positively correlated with biomass accumulation amount and lint yield. In summary, the irrigation regimes of 2 times of irrigation at the squaring stage with a single irrigation amount of 45 mm and 6 times of irrigation at the flowering and boll setting stage with a single irrigation amount of 69 mm can be applied to the non-film cotton cultivation mode in southern Xinjiang. Our findings provide a reference for the application of agricultural internet of things technology in soil hydrothermal microenvironment of non-film cotton fields in Xinjiang.

Results of evaluation of cotton samples (<i>Gossypium hirsutum L.</i>) under cultivation in the Astrakhan region

Relevance. For the intensification of cotton growing, an important component is availability of varieties adapted to specific growing conditions, capable of forming a crop in extreme climatic conditions and with optimal economically valuable characteristics. Therefore, the agrobiological study, evaluation and selection in the natural and climatic conditions of the Astrakhan region of promising and high-yielding cotton samples of various origins in order to involve the selected samples in further breeding work is relevant. Methodology. The cotton collection of the All-Russian Institute of Plant Genetic Resources named after N. I. Vavilov served as the material for variety study. During the research work, the scheme of the selection process was built in accordance with the methodological instructions of N. P. Goncharov. The technique of laying and conducting field experience was according to the methodology of B. A. Dospekhov. The accounts, observations and measurements in the experiment were carried out in accordance with the G. G. Davidyan's methodological guidelines for the study of collection of spinning crops. The assessment of agroclimatic conditions for the growth and development of cotton was carried out by the calculation method. Interpretation of experimental data was carried out by common statistical methods, specifically, digital material was processed using variational statistics. Results. As a result of variety study of cotton, samples capable to adapt to the zone of growth, as well as productive and with optimal economically valuable characteristics were identified. These qualities make it possible to use the selected samples for further breeding.