Highest Cotton Yield Research Articles

Integrated Effects of Mulching Treatment and Nitrogen Fertilization on Cotton Performance under Dryland Agriculture

ABSTRACTCrop production in arid regions is characterized with high temperature, drought and salinity which decrease water and nutrient use efficiency. This study was conducted to investigate the effect of wheat residue mulch in relation to N fertilizer application rates for cotton productivity under dryland condition of Uzbekistan. Main plots were control of no mulch addition and a 5 t ha−1 mulch treatment. These plots were split into 5 N rate plots of 0, 70, 140, 210 or 280 kg of N ha−1. The results showed that mulching pattern decreased soil temperature by 0.7–1.5°C as compared to conventional treatment (CT), regardless of N fertilization rates. The soil water storage increased by 41.8, 17.3, 48.0 mm in the flowering, boll formation and ripening stages of cotton, respectively under mulching treatment. Soil available N concentration and nutrients uptake by plants consistently increased with the increase of N fertilization rates with positive correlations. At flowering period, the plant height, chlorophyll content, stem diameter, and a number of fruit branches in plants were higher by 32.3%, 46.8%, 26.7% and 55.3%, respectively at 210 kg N ha−1 under mulching treatment as compared to the non-fertilized control. The highest cotton yield was obtained at 210 kg N ha−1 application under mulching treatment. The correlation difference between mulch and N application rates was higher (R2 = 0.97) than the difference in CTs and N application rates (R2 = 0.89). This study showed that mulching had a greater impact to preserve nutrients and water resources in the soil, thereby improved cotton growth and yield.

Functional diversifications of GhERF1 duplicate genes after the formation of allotetraploid cotton.

Whole genome duplication, a prevalent force of evolution in plants, results in massive genome restructuring in different organisms. Roles of the resultant duplicated genes are poorly understood, both functionally and evolutionarily. In the present study, differentially expressed ethylene responsive factors (GhERF1s), anchored on Chr-A07 and Chr-D07, were isolated from a high-yielding cotton hybrid (XZM2) and its parents. The GhERF1 was located in the B3 subgroup of the ethylene responsive factors subfamily involved in conferring tolerance to abiotic stress. Nucleotide sequence analysis of 524 diverse accessions, together with quantitative real-time polymerase chain reaction analysis, elucidated that de-functionalization of GhERF1-7A occurred due to one base insertion following formation of the allotetraploid cotton. Our quantitative trait loci and association mapping analyses highlighted a role for GhERF1-7A in conferring high boll number per plant in modern cotton cultivars. Overexpression of GhERF1-7A in transgenic Arabidopsis resulted in a substantial increase in the number of siliques and total seed yield. Neo-functionalization of GhERF1-7A was also observed in modern cultivars rather than in races and/or landraces, further supporting its role in the development of high-yielding cotton cultivars. Both de- and neo-functionalization occurred in one of the duplicate genes, thus providing new genomic insight into the evolution of allotetraploid cotton species.

A genome-wide association study uncovers novel genomic regions and candidate genes of yield-related traits in upland cotton.

A total of 62 SNPs associated with yield-related traits were identified by a GWAS. Based on significant SNPs, two candidate genes pleiotropically increase lint yield. Improved fibre yield is considered a constant goal of upland cotton (Gossypium hirsutum) breeding worldwide, but the understanding of the genetic basis controlling yield-related traits remains limited. To better decipher the molecular mechanism underlying these traits, we conducted a genome-wide association study to determine candidate loci associated with six yield-related traits in a population of 719 upland cotton germplasm accessions; to accomplish this, we used 10,511 single-nucleotide polymorphisms (SNPs) genotyped by an Illumina CottonSNP63K array. Six traits, including the boll number, boll weight, lint percentage, fruit branch number, seed index and lint index, were assessed in multiple environments; large variation in all phenotypes was detected across accessions. We identified 62 SNP loci that were significantly associated with different traits on chromosomes A07, D03, D05, D09, D10 and D12. A total of 689 candidate genes were screened, and 27 of them contained at least one significant SNP. Furthermore, two genes (Gh_D03G1064 and Gh_D12G2354) that pleiotropically increase lint yield were identified. These identified SNPs and candidate genes provide important insights into the genetic control underlying high yields in G. hirsutum, ultimately facilitating breeding programmes of high-yielding cotton.

Auxin homeostasis and signaling alterations result in the aberrant phenotype in scl mutant of cotton (Gossypium hirsutum L.)

Leaves are the most important organs for photosynthesis. Many cotton leaf mutants (Gossypium spp.) have been reported and broadened the insights of leaf development. A natural occurring small, crinkled leaf (scl) mutant of upland cotton (Gossypium hirsutum L.) occurs in SY321 (wild type, WT), a high-yield upland cotton cultivar that is widely planted in China. The scl has a small and crinkled leaf phenotype. The shoot apical meristem (SAM) of scl did not form the essential typical layered structure, and the cell layers were arranged in a disordered manner. The free IAA concentration of shoot tips was significantly reduced in the scl according to ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. Gene expression profiles showed that 432 genes were differentially expressed between scl and WT. The top 20 enriched pathways were analyzed using the Kyoto encyclopedia of genes and genomes (KEGG) database and four pathways, including flavonoid biosynthesis, photosynthesis, RNA transport, and carbon fixation in photosynthetic organisms, were considered as significantly enriched pathways. Furthermore, a number of differentially expressed genes related to auxin activity, including flavonoids biosynthesis, auxin perception and signal transduction pathway, auxin transport, and ubiquitin-mediated proteolysis pathways, were identified, and the altered expressions of these genes might be responsible for the aberrant phenotype of the scl.

BRS 430 B2RF and BRS 432 B2RF: Insect-resistant and glyphosate-tolerant high-yielding cotton cultivars

Abstract Transgenic cotton cultivars BRS 430 B2RF and BRS 432 B2RF, medium and late season respectively, were developed by EMBRAPA in partnership with Bahia Foundation, aiming to create a high-yielding germplasm. The Bt toxins Cry1Ac and Cry2Ab target lepidopteran pests and the CP4-EPSPS gene confers tolerance to the herbicide glyphosate.

Nutrient Uptake by High-Yielding Cotton Crop in Brazil

ABSTRACT: Determining nutrient uptake and accumulation rates by cotton crops is important to define management strategies, especially for transgenic varieties, which are cultivated using high-technology approaches that require substantial investment to maximize yield. Currently in Brazil, the states of Bahia and Mato Grosso are responsible for 84.4 % of the total cotton growing area. In the present study, two trials were conducted in 2013, one that involved planting FM 940 GLT, FM 980 GLT, and FM 913 GLT varieties in [...]

Root growth and spatial distribution characteristics for seedlings raised in substrate and transplanted cotton.

In this study, transplanting cotton seedlings grown in artificial substrate is considered due to recent increased interest in cotton planting labor saving approaches. The nursery methods used for growing cotton seedlings affect root growth. However, the underlying functional responses of root growth to variations in cotton seedling transplanting methods are poorly understood. We assessed the responses of cotton (Gossypium hirsutum L.) roots to different planting methods by conducting cotton field experiments in 2012 and 2013. A one-factor random block design was used with three replications and three different cotton planting patterns (substrate seedling transplanted cotton (SSTC), soil-cube seedling transplanted cotton (ScSTC) and directly sown cotton (DSC). The distributions and variances of the root area density (RAD) and root length density (RLD) at different cotton growing stages and several yield components were determined. Overall, the following results were observed: 1) The RAD and RLD were greatest near the plants (a horizontal distance of 0 cm) but were lower at W20 and W40 cm in the absence of film mulching than at E20 and E40 cm with film mulching. 2) The roots were confined to shallow depths (20–40 cm), and the root depths of SSTC and DSC were greater than the root depths of ScSTC. 3) Strong root growth was observed in the SSTC at the cotton flowering and boll setting stages. In addition, early onset root growth occurred in the ScSTC, and vigorous root growth occurred throughout all cotton growth stages in DSC. 4) The SSTC plants had more lateral roots with higher root biomass (RB) than the ScSTC, which resulted in higher cotton yields. However, the early onset root growth in the ScSTC resulted in greater pre-frost seed cotton (PFSC) yields. These results can be used to infer how cotton roots are distributed in soils and capture nutrients.

Development of superior hybrids for fibre quality based on heterosis and combining ability in upland cotton (Gossypium hirsutum L.)

The cultivated Gossypium spp. represents the most important, natural fibre crop in the world. Breeding for high cotton yield is still the primary goal of cotton breeding programs, but improving fibre quality has become increasingly important. The enhancement of fibre quality traits like fibre length, strength, and fibre fineness is an essential requirement for the modern textile industry. The objective of this study was to facilitate the selection in cotton breeding program and estimate the general combining ability (GCA) of the parents and specific combining ability (SCA) of hybrids considered for the development of high yielding and better fiber quality in early generations. The study was carried out at cotton research area, CCS Haryana Agricultural University, Hisar (India) during 2014 and 2015 kharif season. Fifteen cotton lines (which have maximum diversity) and four testers (which are known as well adapted and high yielding) were crossed in a line x tester mating design in 2014. Nineteen genotypes and 60 F1 hybrids were planted in the randomized complete block design with three replications at the same experimental area in 2015. The ratio of δ2 GCA /δ2 SCA was less than unity for all the nine characters indicating preponderance of non-additive gene action (dominance and epistasis), which is an important in exploitation of heterosis through hybrid breeding. The best general combining ability was detected from the parent H1470 for seed cotton yield, H1464 and H1098-i for fiber quality traits. SCA was significant for AC726 x H1236, ISR12 x H1226, HR1 x H1117 hybrid combinations for yield and fiber quality. The crosses H1470 x H1236 and H1470 x H1098-i were reported good heterosis for seed cotton yield as well as for fibre quality, selected the best hybrids were H1464 x H1098-i and H1463 x H1226. These cross combinations involved at least one parent with high or average GCA effect for a particular trait. The cross combination involving H1470, H1098-i and H1464 parents’ recorded significant positive heterosis with acceptable SCA effect for both yield and fibre quality parameters. This investigation concluded that the parents H1470, H1098-i and H1464 can be used in hybrid development programme with better fibre quality.

Spatial configuration drives complementary capture of light of the understory cotton in young jujube plantations

In intercropping systems (growing >1 species in a field), interactions between species affect the performance of plants and the overall yield. These interactions lead to plastic responses in plant traits due to the specific environmental conditions typical for intercrops, especially in agroforestry in which the understory crop is strongly shaded by the trees. To quantify the extent to how physiological plasticity is driven by inter-specific competition, field experiments with mixtures of cotton and jujube trees grown in strips were conducted in 2012 and 2013 in Hetian, Xinjiang, China. Cotton was grown at three levels of inter-specific competition, represented by the distance between the adjacent cotton and tree rows without change in plant density. The highest cotton yield was attained farthest away from the trees, i.e. at the lowest level of inter-specific competition, with a higher proportion of fiber in the bolls as well as a higher boll density compared to plants grown at higher inter-specific competition. Low inter-specific competition also increased maximum leaf area index (LAI), total light interception and dry matter accumulation. However, light-use efficiency was higher at high levels of inter-specific competition especially in the rows close to the tree line, associated with a higher fraction of diffuse radiation. These results aid in the optimization of the spatial pattern of crops in agroforestry system.

Effects of polymer-coated potassium chloride on cotton yield, leaf senescence and soil potassium

Potassium (K) is one of the most important nutrients influencing plants, including cotton growth and metabolism. Because of toxicity from chloride ions, potassium sulfate (K2SO4) usually is used instead as a potassium fertilizer, especially for cotton, although it is lower in K2O content and dearer than potassium chloride (KCl). The objective of this study was to investigate the effects of polymer-coated potassium chloride (PCPC) fertilization on cotton yields, yield components, fiber qualities, potassium use efficiencies and leaf senescence under saline conditions. A 2-yr field experiment was conducted in the Yellow River Delta of China with a high-yielding cotton cultivar (‘Guoxin 99-1’). The experiment had the following six treatments with varying potassium fertilization: 70% PCPC mixed with 30% K2SO4 applied once before planting; PCPC applied once before planting; K2SO4 (KCl) applied twice with one application (40%) before planting and second application (60%) during first bloom stage; K2SO4 (KCl) applied once before planting; and fertilization none potassium as the control. The release rate of PCPC appeared to be slow before the squaring stage, but accelerated between the first bloom and boll-setting stages, and then decreased during the late stage including harvest. The number of cotton bolls was 8.99–19.71% higher and seed yields 4.39–28.10% higher, in 70% PCPC mixed with 30% K2SO4 treatment than in the other potassium fertilizer treatments. Also, the potassium recovery efficiency and net profits were increased by 3.38–40.90% and 5.77–137.26%, respectively, in the 70% PCPC mixed with 30% K2SO4 compared with the other potassium fertilizer treatments. Available soil potassium contents, fiber qualities and leaf photosynthetic indices were all significantly improved by using PCPC instead of the more standard potassium fertilizers. Hence, combining PCPC with K2SO4 at a 7:3 potassium ratio can delay leaf senescence, increase yields and fiber qualities, and improve potassium use efficiencies and economic benefits in cotton.

Intercropping and balanced nutrient management for sustainable cotton production

ABSTRACTThe productivity of cotton is lowest in India and far below that of the world average productivity. Suitable management practices like intercropping and judicious combination of organic and inorganic manures are considered as yield improvement technologies and can avoid environmental pollution. However, which intercrop is suitable for the study area and what combination of nutrients will perform better needs to be investiaged. With this background and to test-verify the same, field experiments were conducted on cotton with split plot design to evaluate cotton based intercropping system along with nutrient management practices for enhancing the cotton productivity. Five intercropping systems viz., sole cotton, cotton + onion, cotton + blackgram, cotton + greengram and cotton + lucerne were included in the main plot. The subplot consisted of combinations of inorganic and organic manures namely, 100% recommended inorganic nitrogen (N), 75% inorganic N + 25% N through poultry manure, 75% inorganic N + 25% N through sunnhemp, 75% inorganic N + 25% N through farm wastes, 75% inorganic N + 25% N through weed compost. The results revealed that sole cotton followed by cotton + blackgram intercropping and 75% inorganic N + 25% N through poultry manure recorded better growth and yield attributes, higher cotton yield during both the years. Cotton + onion resulted in the maximum cotton equivalent yield of 2396 kg ha−1 followed by cotton + blackgram (2240 kg ha−1). Better N use efficiency and post-harvest soil available N, phosphorus (P) and potassium (K) was also associated with cotton + blackgram intercropping and 75% inorganic N + 25% N through poultry manure. Benefit: cost (BC) ratios were also higher in the same treatment. It could be concluded from these results that the cotton productivity is higher under the sole crop of cotton, however, the cotton equivalent yield is significantly higher with intercropping and these treatments proved that soil fertility status can be sustained with integrated plant nutrient management practices and intercropping systems.

Effects of wheat straw incorporation in cotton-wheat double cropping system on nutrient status and growth in cotton

Soil potassium deficiency causes cotton (Gossypium hirsutum L.) yield decline, which China addresses through the importation of costly inorganic potassium. While applying inorganic potassium fertilizer in long-term would cause environmental issues. The feasibility of wheat straw incorporation replacing inorganic potassium for soil available potassium concentration in cotton-wheat double cropping system has been confirmed in the previous study. However, little is known about the dynamics of the nutrient concentrations and growth in cotton grown under wheat straw incorporation and inorganic potassium application. Based on the production reality in cotton-wheat double cropping system, total and half wheat straw incorporation (9000 and 4500kgha−1), high- and super-high-yielding management requiring inorganic potassium application (150 and 300kgK2Oha−1), and control (without wheat straw or inorganic potassium) conditions were set. The 3-year in-situ field experiments were conducted in Nanjing and Dafeng, China, on clay- and sandy-loam soil with initial (2011) available potassium of 155 and 316mgkg−1, respectively. The results indicated that nitrogen and phosphorus concentrations in cotton were little affected. Potassium concentrations in cotton under wheat straw incorporation of 9000kgha−1 in Nanjing and 4500 and 9000kgha−1 in Dafeng were consistent with those under inorganic potassium applications. Cotton biomass increments under inorganic potassium applications were greater than wheat straw incorporations at the late growth period. In Nanjing in 2013, seedcotton yield under wheat straw incorporation of 9000kgha−1 was similar to that of 150kgK2Oha−1, but was markedly lower than that of 300kgK2Oha−1. Wheat straw incorporation enhanced green leaf area duration (LAD) at the late period of cotton growth, while LAD remained longer under inorganic potassium. Relative growth rate (RGR) and net assimilation rate (NAR) of cotton under wheat straw incorporation were lower than those under inorganic potassium application. Greater cotton biomass increment at the late growth period under inorganic potassium applications were probably more because LAD remained longer, rather than RGR and NAR greater. These results showed that the short-term (3 years) strategy of incorporating 9000kgha−1 wheat straw to replace inorganic potassium (150kgK2Oha−1) was effective for high-yielding cotton production.

English

English

The Effect of Harvesting Time and Variety on Fiber andCottonStalkYield Potential and its Companent for Use in the Pulp andPaperIndustry

Survey of cotton fiber yield, in addition to the identification of its best variety can cause cotton residual enhancement. The remainder of cotton stalk in farms is an illness-causing agent and leads to yield reduction in the next cultivation stage, an event which requires burial. So the usage of cotton stalk in the pulp and paper industry,which faces a shortage of raw material, results in a reduction intillage costs, thus, fiber and stalk yield potential gain importance. In this study, we investigated the effect of variety and harvesting time on cotton yield and its components, which was obtained from experiments of the plot of the 2009 cultivation year. An amount of dry material of each part of the components was also obtained. Experiments on factors containedfive varieties: Sepid, Sahel, Armaghan, Golestan and number200. The harvesting times were also three, namely: 145, 175 and 205 days after cultivation replicated in 4 blocks. Results of the variance analysis showed that the effects of variety and harvesting time on total dry material yields, leaf, stalk, bast and the core, cotton yield, empty and closed boll, stalk height and diameter were significated. The Armaghan variety in the second harvesting time had the highest cotton yield(2413.95) ,whilethe Sepid variety had the most cotton stalk yield in the third harvesting time(3716.76). Except for boll, cotton and total dry material yield, in the other evaluated characteristics, the third harvesting time had the best yield, and the most total dry material yield was related to the second harvesting time.

Nitrogen fertiliser requirements of high-yielding irrigated transgenic cotton

Nitrogen (N) fertiliser is almost universally used in high-yielding irrigated cotton, but it is not used efficiently in many instances. Predicting the economic optimal amount of N fertiliser is difficult and often little N fertiliser is required where situations have provided access to N through excessive N fertiliser being applied to previous cotton crops, conditions promoting significant N mineralisation, or if legume rotation crops were grown. The economic optimum N fertiliser rate (Nopt – where the marginal cost of N fertiliser (at $1.50 kg–1 N) equalled the return on cotton lint (at $2.20 kg–1) was determined in eight experiments conducted over 8 years; Nopt ranged from 0 to 248 kg N ha–1, lint yields ranged from 1.3 to 3.4 t ha–1, crop N uptake ranged from 96 to 321 kg N ha–1 and apparent N fertiliser recovery (calculated by dividing the difference in crop N uptake between N-fertilised and unfertilised plots by the N fertiliser applied) ranged from 20% to 98% of N applied. A positive response to N fertiliser application in lint yield was evident in 7 of the 8 years. Both lint yield and crop N uptake were positively correlated with pre-sowing soil nitrate concentration. Cotton that yielded 1.4 t lint ha–1 derived 78% of crop N from the soil, whereas at 3.4 t lint ha–1, 69% of crop N was derived from soil; this indicated the importance of N supplied from the soil and the relatively lesser reliance on the N fertiliser applied, even for very high-yielding cotton. A multiple regression model, using the parameters of pre-sowing soil nitrate, crop N uptake and lint yield, more accurately represented the data generated in this study in estimating the economic optimum N fertiliser rate (r2 = 0.80).

Biological and Chemical Techniques for Integrated Control of the Spiny Bollworm, Earias insulana (Boisd.) (Lep., Noctuidae)

Field experiments were carried out during the cotton seasons of 2103 and 2014 in a private farm at Abo-Homos District, El-Behaira Governorate to evaluate the efficiency of the release of the parasitoid Trichogramma evanescens alone orin different combinations with different insecticides on the mean numbers of the cotton spiny bollworm (Earias insulana) (Boisd) larvae, in addition to their effect on seed cotton yield and economic loss.The obtained results indicated that the treatmental combination of the parasitoid T. evanescens+ Radiant® gave the lowest infestation level (1.22 larvae/75 bolls) as compared with the untreated check (17.61 larvae/75 bolls) during the cotton season of 2013. Meanwhile, T. evanescens+ Pleo® gave the highest seed cotton yield (8.98 ken / fed.), versus the lower one of the untreated check (4.31 ken / fed.). Also, the treatmental combination of T. evanescens+ Fertilizer (Novatic slop 48®) + different insecticides (Oshin®, Nomolt® and Pestban®) gave the lowest loss of cotton bolls (10.00%) and more or less higher cotton yield and loss of bolls in comparison to the untreated check (4.31ken / fed. and 49.20%, respectively) during the same cotton season of 2013. During the cotton season of 2014, the performed combination of Trichogramma evanescens+ Fertilizer + consequential insecticides (Oshin®, Nomolt®and Radiant®) gave the lowest larval infestation (0.50 larvae/75 bolls ) as compared with the untreated check (17.33 larvae/ 75 bolls). By the end of 2014 cotton season, the treatment of T. evanescens + (Pleo®, Challenger® and Pleo®) gave the highest seed cotton yield of 9.43 ken / fed. and the lowest loss of cotton bolls (6.50%) in comparison to the untreated check (4.14 ken and 48.50%, respectively ). It could be concluded that all the performed treatments of the release of T. evanescens in combinations with the tested insecticides showed the best integration for bollworms control and recorded higher yield and lower loss value than those of the untreated check.

Effect of Deficit Irrigation on the Growth, Water Use Characteristics and Yield of Cotton in Arid Northwest China

Water shortage is a key constraint to sustainable agricultural production in Xinjiang, Northwest China. To enhance the use efficiency of valuable irrigation water resources, a 2–year experiment (2010–2011) was conducted to quantify the response of cotton (Gossypium hirsutum L.) growth and yield to different degrees of deficit irrigation (DI) regimes; to determine the effects of DI on the characteristics of water use for cotton, seasonal water use, available soil water in the root zone, soil water depletion, evapotranspiration (ET)–based water use efficiency and irrigation–based water use efficiency, and to determine the best DI regime for optimal water–saving and yield output. The plots were irrigated at 100% (100ET), 85% (85ET), 70% (70ET), 55% (55ET) and 45% (45ET) of the regional ET of cotton in northern Xinjiang. The effect of DI irrigation on water use characteristics was evaluated by analyzing available soil water and soil water depletion in the root zone along with water use efficiencies of cotton. The study showed that the growth, water use characteristics and yield of cotton varied with irrigation regime. Seasonal ET and seed cotton yield were linearly correlated with irrigation amount. The second–order polynomial equation best approximated water–yield relationship of cotton in the study area. Cotton yield response factor was 0.65, suggesting limited water conditions were suitable for cotton cultivation. Economic evaluation of DI treatments confirmed that the yield loss was less than 10% under 70ET and 85ET, which was acceptable for greater sustainability. The results suggested that proper DI schemes were necessary for sustainable cotton production in the region. While irrigation at 85ET was safe for high cotton yield, irrigation at 70ET was a viable alternative under limited irrigation water availability.

High Yielding Cotton Produced without Excessive Nitrous Oxide Emissions

Excessive N fertilizer use leads to enhanced nitrous oxide (N2O) emissions from cotton (Gossypium hirsutum L.) production systems. The objective of the study was to quantify nitrous oxide emissions from the ridges within a furrow‐irrigated field during the growth of a cotton crop that had been fertilized with urea at 0, 120, 200, or 320 kg N ha−1. No measurements were taken from the furrows; we assumed similar N2O emissions from the furrows in this system. The N2O emissions increased exponentially with N fertilizer rate. Over the cotton‐growing season, N2O emissions totalled 0.51, 0.95, 0.78, and 10.62 kg N2O‐N ha−1, for the four respective N fertilizer rates. The cotton phase of the cotton–faba bean (Vicia faba L.)–fallow rotation was the main contributor to the total N2O emission. Over this 2‐yr rotation, emissions totalled 1.23, 1.65, 1.44, and 11.48 kg N2O‐N ha−1. However, <0.35% of the N fertilizer applied was emitted as N2O for the complete rotation where the economic optimal N fertilizer rate for the cotton crop was not exceeded. More than 3.5% of the N fertilizer was emitted as N2O where 320 kg N ha−1 was applied, which was estimated to represent about 11 kg N ha−1. These data indicate that supra‐optimal N fertilizer applications increase the net emissions of N2O from the ridges in high‐yielding furrow‐irrigated cropping systems. The N2O emissions could be decreased further by reducing or eliminating the time in fallow.

Quantifying the Impact Factors of Different Forms of Potassium and Absorptions by Different Cotton Genotypes

This study focuses on two genotypes of cotton and explores different factors that were able to affect the release of different forms of potassium (K) in the rhizosphere by considering a biogeochemical process integrating plants, soils, and microorganisms. The study indicated that both genotypes of cotton could effectively absorb exchangeable potassium (eK) under limited potassium (LK) supply, and cotton plants could use LK to sustain offspring, preferably under K-deficiency conditions. It was mainly due to its significantly greater active absorbing surface area of root and comparatively greater K+ maximum uptake rate (Imax), which caused more K accumulation in the high-efficiency genotype cotton (HEG). Although Imax of the low-efficiency genotype cotton’s (LEG’s) was greater, K accumulation in LEG was less, which might be attributed to its significantly lower HEG and feedback inhibition on K taken up by greater K concentration in the plant. The lint yield had a significant positive correlation with boll number per plant, single boll weight, plant height, and number of fruit branches, which indicated that increasing these agronomic parameters is the base for increasing lint yield. There was a synergic action among humus, microorganisms, and K in the rhizosphere soil. The cation exchange capacity (CEC) of reduced soils was less under oxidized condition, due to collapse of the interlayer in response to increased layer charge upon structural Fe reduction. Crop yields can be increased when fertilizer K is applied according to proper ratio among different forms of potassium and humic acid in soils. The middle-high plant height, lower initial fruit branch, more fruit branches, more bolls, and larger boll size should receive more attention during high-yielding cotton breeding.

Arabidopsis EDT1/HDG11 improves drought and salt tolerance in cotton and poplar and increases cotton yield in the field.

Drought and salinity are two major environmental factors limiting crop production worldwide. Improvement of drought and salt tolerance of crops with transgenic approach is an effective strategy to meet the demand of the ever-growing world population. Arabidopsis ENHANCED DROUGHT TOLERANCE1/HOMEODOMAIN GLABROUS11 (AtEDT1/HDG11), a homeodomain-START transcription factor, has been demonstrated to significantly improve drought tolerance in Arabidopsis, tobacco, tall fescue and rice. Here we report that AtHDG11 also confers drought and salt tolerance in upland cotton (Gossypium hirsutum) and woody plant poplar (Populus tomentosa Carr.). Our results showed that both the transgenic cotton and poplar exhibited significantly enhanced tolerance to drought and salt stress with well-developed root system. In the leaves of the transgenic cotton plants, proline content, soluble sugar content and activities of reactive oxygen species-scavenging enzymes were significantly increased after drought and salt stress compared with wild type. Leaf stomatal density was significantly reduced, whereas stomatal and leaf epidermal cell size were significantly increased in both the transgenic cotton and poplar plants. More importantly, the transgenic cotton showed significantly improved drought tolerance and better agronomic performance with higher cotton yield in the field both under normal and drought conditions. These results demonstrate that AtHDG11 is not only a promising candidate for crops improvement but also for woody plants.