Higher Seed Cotton Yield Research Articles

Yield and fiber quality traits of cotton (Gossypium hirsutum L.) cultivars analyzed by biplot method

BackgroundCotton is a vital fiber crop fulfilling global demands for raw materials in the textile sector. Therefore, high-yielding cultivars with superior-quality traits are desired at regional scales. The high-yielding cultivars can be selected by determining their responses to various environmental conditions at different locations over a short or long period. Genotypes, environment, and year significantly alter seed cotton yield and fiber quality. Therefore, determining the response to various environmental conditions is necessary for selecting high-yielding cultivars with superior fiber quality. MethodsThis study determined the yield and fiber quality traits of 3 cotton cultivars (i.e., ‘DP396′, ‘BA440′ and ‘Teksa 415′) at five different locations (i.e., Tepe, Boztepe, Bozçalı, Köseli and GAP International Agricultural Research and Training Center) in southeastern Anatolia, Turkey for 3 years (2019, 2020, and 2021). Data relating to seed cotton yield and fiber quality traits were collected and relationships of these traits were determined by biplot analysis. ResultsCultivars × traits relationship indicated that ‘DP396′ was the most stable cultivar with the highest seed cotton yield. Similarly, ‘BA440′ cultivar was associated with quality characteristics. Sector analysis divided the yield and quality traits into three different groups. The locations × traits relationship indicated that the examined traits differed according to the locations. Tepe location was in the center in terms of quality and seed yield, whereas Bozçalı location had superior quality traits. Likewise, Boztepe location resulted in higher values ​​ of seed and fiber yield, and number of bolls per plant. The studied characteristics varied among the years, and higher values of seed and fiber yields, and the number of bolls per plant were recorded during 2019. On the other hand, superior fiber quality traits were noted during 2021. ConclusionsIt is concluded that ‘DP396′ was the most stable cultivar for seed cotton yield, whereas ‘BA440′ was stable for quality traits. Therefore, these cultivars can be used in the studied locations to increase yield and fiber quality. Furthermore, these cultivars could be utilized in the breeding programs for developing high-yielding and better fiber quality producing genotypes in the future.

Assessment of bioagents against cotton diseases under South Gujarat of India

Cotton (Gossypium spp.) is one of the most important economic products of the group of fibres due to volume and value of production. Its cultivation is also of great social importance, due to the number of jobs generated directly or indirectly. The fibre, the main product of cotton has many industrial applications. The manufacturing of yarn for weaving of various kinds of fabrics, cotton batting for hospital use, felt clothing, blankets and upholstery, photographic films and plates for radiography among others. Here in this experiment, different bioagents were evaluated against the cotton foliar disease. This experiment engage the total nine treatments including control from which, treatment T5 (14.50 PDI) (Seed and soil application Pf CICR i.e., seed application: 108cfu/g @10g per kg of seed soil application: 2.5 kg/ha at 30 and 60 DAS) followed by T8 (18.33 PDI) significantly recorded minimum bacterial leaf blight infection in comparison to the treatment T9 i.e. control (42.33 PDI) in RCH 2 BG II hybrid. For Alternaria leaf spot disease, treatment T8 (8.17 PDI) (Seed treatment with Pseudomonas fluorescens CICR (2 x 108cfu/g) @ 10 g/kg seed + soil application of Trichoderma viride TNAU1 (2 x 106 cfu/g) @ 2.5 kg/ha in 250 kg of vermicompost and sprays of Kresoxim methyl (0.0443%) followed by Captan 70% + Hexaconazole 5% WP @ 1.5 g/l) were recorded significantly minimum Alternaria leaf spot disease in RCH 2 BG II hybrid as compared to the T9 i.e. control (19.33 PDI) followed by T7 (9.83 PDI) and T3 (10.50 PDI) treatment. The highest seed cotton yield was recorded in the treatment T5 (2606.00 kg/ha) followed by treatment T8 (2335.33 kg/ha) and treatment T7 (2275.67 kg/ha), respectively.

Plant density influences yield, yield components, lint quality and seed oil content of cotton genotypes

Choosing suitable varieties and manipulating plant population are crucial management aspects in any cropping system that goals to improve yield, quality and the balance between plant demand and environmental resource availability. A two-year field experiment was conducted at Tehran, Iran, in a split plot design and replicated thrice to examine the effect of the planting density (low, moderate and high) on ten cotton genotypes. In term of lint yield and among the cotton genotypes G8 (1269 kg · ha−1), G4 (1263 kg · ha−1), G1 (1239 kg · ha−1) and G2 (1123 kg · ha−1) were statistically at par with each other but significantly superior to G7 (914 kg · ha−1) and G9 (936 kg · ha−1). Lint yield in high plant density (1386 kg · ha−1) was found to be remarkably superior over medium and low plant density (1029 and 890 kg · ha−1, respectively) by average of 25.7% and 35.7%, respectively. Cotton genotypes at low plant density had higher boll plant−1 (6.46% and 15.3%, respectively), lint percentage (5.8% and 12%, respectively) and lint strength (0.6% and 1.9%, respectively) compared to moderate and high plant densities. The genotypes cultivated at high plant density produced higher seed and lint yield, higher lint elasticity and lower seed oil content, lint length and lint quality index. Based on this experiment, it is concluded that high seed cotton yield can be achieved at high plant density while higher lint quality can be yielded at low plant density.

Influence of time of planting and genotypes on leaf reddening, seed-cotton yield and productivity efficiency in Bt cotton (Gossypium hirsutum)

A field experiment was conducted during 2014–15 and 2015–16 at College of Agriculture, University of Agricultural Sciences, Raichur, Karnataka, India, to study the interaction between cultivars (‘Bindas’, ‘Bunny-Bt’, ‘ATM’ and ‘Dr. Brent’) and planting time (II fortnight of June, and I and II first fortnights of July and August) on leaf reddening, seed-cotton yield and productivity efficiency, and a new measure to assess reddening tolerance in Bt cotton (Gossypium hirsutum L.). Early sowing during June II fortnight particularly with cv. ‘Bindas’ showed lower leafreddening indices [0, 0, 0.62 and 0.86 at 90, 105, 120 and 135 days after sowing (DAS), respectively], higher seed-cotton yield (4.17 t/ha) and consequently higher productivity efficiency (0.48). However, higher leaf reddening (1.55, 1.99, 2.00 and 2.60, 1.67, 1.97, 1.99 and 2.56 at 90, 105, 120 and 135 DAS respectively) and lower seed-cotton yield (0.86 and 0.84 t/ha respectively) resulting in lower productivity efficiency (0.13 and 0.13 respectively) were registered with delayed sowing during II fortnight of August, particularly with reddening susceptible cultivars ‘Bunny-Bt’ and ‘Dr Brent’. In all, productivity efficiency emerged as effective inclusive tool in assessing leafreddening tolerance over leaf-reddening index alone in Bt cotton cultivars.

The Effect of Application of Different Doses of Acid Mixture Seed Coating Method on Cotton (Gossypium hirsutum L.) Yield and Fiber Technological Characteristics

This study was carried out to determine the effects of different rates of seed coating of an organic acid mixture (citric acid, glutamate, and proline) on the yield and technological characteristics of cotton (Gossypium hirsutum L.). Before seeding, cotton seeds were coated with an organic acid mixture product [0.75% citric acid, 0.25% glutamate, 0.25% proline, and 98.75 inert ingredients (water)], in six different doses (500, 1000, 1500, 2000, and 2500 cc) to compare with control (uncoated). Seed cotton yield, fiber yield, plant height, number of monopodial branches, number of sympodial branches, number of nodes of the first fruiting branch, number of bolls per plant, boll weight, boll seed cotton weight, first picking percentage, 100 seeds weight, fiber fineness, fiber length, fiber strength, fiber elongation, fiber uniformity ratio, short fiber index, fiber yellowness (+ b), fiber reflectance (Rd) and spinning consistency index (SCI) values were examined. The results of statistical analysis indicated that there were significant differences between treatments in terms of seed cotton yield, fiber yield, boll weight, boll seed cotton weight, first picking percentage, and the number of nodes of the first fruiting branch, while there was a non-significant association in terms of other examined observations and fiber technological characteristics. The highest seed cotton yield was obtained from 1500 cc application doses as 5073.80 kg ha-1 which was 19,78% (838.00 kg ha-1) higher than that of the control (4235.80 kg ha-1). In conclusion in light of the information obtained from this study, a remarkable increase in yield was obtained as a result of coating the cotton seeds with the product containing organic acid mixtures (citric acid, glutamate, and proline) at different doses. For this reason, it was concluded that it may be recommended to cover the seeds with the aforementioned mixtures before sowing.

Response of Cotton (Gossypium hirsutum L.) Cultivar (Barac 67/B) to Sowing Dates under Normal Irrigation Conditions at New Halfa, Sudan

Field experiments were conducted at New Halfa Research Farm, Agricultural Research Corporation (ARC), Sudan during the two consecutive seasons, (2008/2009 and 2009/2010), to study the effect of sowing date on growth, yield and yield components of cotton cultivar (Barac 67B), under irrigation conditions. Six sowing dates (Mid June, first July, mid-July, 1st August, mid-August and end August) were used in this study. Randomized Complete Block design with four replications was used. Observations on seed cotton yield and some agronomic parameters were recorded. Data for each season and combined were statistically analyzed using MSTAT-C. Results indicated that, sowing date significantly affected for all characters under study. It was concluded that, earlier sowing (mid June - mid July) resulted in higher number of bolls/plant. Mid June had longer period to maturity, taller plants (cm) and higher seed cotton yield (kantar/fed).

Genotype × Environment Interaction Analysis for Yield Stability of Hybrid Cotton Across Production Environments Through Multiple Biometrical Tools

ABSTRACT The expected gains in the productivity and sustainability of cotton cultivars across environmental spectra may face many challenges. To address this issue, a set of 572 cotton accessions, including 284 F1 hybrids along with their parental lines and checks, were evaluated and compared across multiple test environments. Popular biometrical tools viz; best linear unbiased prediction (BLUP), additive main effects and multiplicative interaction (AMMI) and genotype main effects and genotype × environment interaction effects (GGE) were utilized for reliable estimation graphical depiction of GEI effects. The first two interaction coordinates as principal components in BLUP, AMMI, and GGE biplots explained the maximum proportion of GEI regarding seed cotton yield. The contrasting environments did not cluster together, thus revealing their varying influences on the genotypes. A set of 44 F1 hybrids featuring higher stability, 46 with higher adaptability, and 5 F1 hybrids exhibited higher stability, adaptability, and highest seed cotton yield across the investigated environments simultaneously. F1 hybrids of cotton were concluded as more stable and adaptable regarding seed cotton yield across environments. Accordingly, switching from line to hybrid breeding could enable a cotton breeding program to address the broader issue of growing this crop in a wide range of target environments.

The Influence of Different Row Spacing and Weed Control Intervals on Weed Infestation and Yield-Related Traits of American (Gossypium hirsutum L.) and Desi (Gossypium arboreum) Cotton

Narrow row spacing has attracted significant attention due to its beneficial impacts on weed management in cotton. This study compared the effects of normal and ultra-narrow row spacing on critical periods of weed control in American (Gossypium hirsutum L.) and ‘Desi’ (Gossypium arboreum) cotton. Two different row spacings (i.e., recommended (75 cm) and ultra-narrow (30 cm)) and three weed control intervals (i.e., weed control at 30, 60 and 90 days after sowing (DAS)) were included in the study. Weedy-check and weed-free treatments were included in the experiment as controls for comparison. ‘Desi’ cotton grown under ultra-narrow spacing recorded the lowest weed density and individual density of Trianthema portulacastarum L., Cyperus rotundus L., Cynodon dactylon L., Echinochloa colona (L.) Link and Digera muricata (L.) Mart. Moreover, ‘Desi’ cotton sown under ultra-narrow spacing with weed-free and weed control at 30 DAS resulted in the highest leaf area index (LAI), leaf area duration (LAD), net assimilation late (NAR), root elongation rate (RER) and root growth rate (RGR) at all sampling dates. Likewise, ‘desi’ cotton sown under recommended row spacing and weed-free conditions produced the highest number of sympodial and monopodial branches, number of flowers and bolls per plant, whereas the highest seed cotton yield of ‘Desi’ cotton was noted under ultra-narrow spacing and weed-free conditions. It is concluded that sowing both cotton types in ultra-narrow row spacing and controlling weeds at 30 DAS will result in lower weed infestation and higher seed cotton yield.

Effect of defoliants on percent defoliation and yield of American cotton (Gossypium hirsutum)

Cotton production is labour intensive in almost all the developing countries where it is picked by hand. However, due to acute labour shortage in recent times, mechanized harvesting is gaining momentum. It requires the application of defoliants, which reduces the cost of labour and maximum cotton can be picked in a single pick (one picking) and consequently provide timely sowing of next crop. The farmers can get benefit of two crops instead of one single long duration cotton crop. Therefore, a two year study conducted at Agricultural College Farm, Bapatla, Andhra Pradesh, during the kharif of 2018–19 and 2019–20 to know the the effect of different defoliants and their time of application on per cent defoliation and seed cotton yield in High Density Planting American Cotton (HDPS).Three defoliants Dropp ultra, mepiquat chloride and etherel and three times of application 80% of boll opening, Node Above Cracked Boll and Node Above White Flower were included in this research in split plot design with four replications. Per cent defoliation was significantly influenced by different defoliant treatments, as well as time of application. At 21 days after defoliant spray, there was significant increase in per cent defoliation with Dropp Ultra 540 SC (Thidiazuron 360 + Diuron 180) @ 250 mL/ha (91.5%) over other defoliants and at 80% Boll Opening (88.3%), which was on par with NACB (86.9%). Higher seed cotton yield was obtained with application of Dropp Ultra @ 250 mL/ha and found on par with Etherel @ 3000 ppm (D3) and regarding times of application, defoliants applied at 80% Boll Opening recorded maximum yield, which was found at par with NACB method.

A Preliminary Study on the Effectiveness of Harpin Protein and Potassium Thiosulphate Foliar Applications on Yield and Quality Characteristics in Second Crop Cotton (Gossypium hirsutum L.)

The foliar applications such as harpin protein and potassium thiosulfate (KTS) play a crucial role in cotton growing under especially adversely soil conditions. This study was conducted to evaluate the different combinations of harpin protein and KTS for yield, yield components and fiber quality in second crop cotton (Gossypium hirsutum L.). The differences among treatments were significant for first picking percentage, seed cotton yield and fiber fineness. The applications of harpin protein at peak squaring and harpin protein at first flowering + after 21 days harpin protein were induced the earliness of cotton. The highest seed cotton yield was recorded in harpin protein at peak squaring with 4231.6 kg ha-1, whereas the fibers became coarser with the harpin protein and KTS applications. Results obtained from the current study indicated the potential effect of harpin protein and KTS on increasing the seed cotton yield.

Determination of Yield, Yield Component Technological and Physiological Characteristics in Different Cotton (Gossypium hirsutum L.) Varieties - I

This study was carried out with the aim of evaluating the performance of the varieties in terms of yield, agronomic, morphological, physiological parameters and fiber quality criteria by using 10 cotton varieties that are widely planted in the Southeastern Anatolia Region. The study was conducted in 2017 in Bismil district of Diyarbakır with 4 replications according to randomized block design. In the study there were statistically significant differences between varieties in terms of seed cotton yield, fiber yield, first picking percentage, ginning percentage, canopy temperature, NDVI value, number of sympodial branches, number of first fruiting branches, number of bolls, boll weight, boll seed weight and all observed fiber technological characteristic, while there were non-significant association for plant height, number of monopodial branches and chlorophyll content (SPAD value). According to the results of analysis it was determined that PG 2018 for seed cotton yield , fiber yield, first node of fruiting branches and canopy temperature, Stoneville 468 and Carla for first picking percentage, Lima for number of sympodial branches, boll weight and ginning outturn, PG 2018 and Lima for number of bolls, DP 499 for boll seed weight, Stoneville 468 and DP 499 for NDVI values and Gloria variety had highest values for technological characteristic. In the study, the variety with higher canopy temperature, which is one of the physiological parameters, had higher seed cotton yield, fiber yield and some important yield components. However, it has been determined that the quality of fiber technological properties does not show parallelism with physiological parameters, quality properties are closely related to genetic structure and are relatively less affected by environmental conditions.

The efficacy of chemical topping in field-grown cotton is mediated by drip irrigation amount in irrigated agricultural area

Abstract Background Cotton production in China is challenged by high labor input including manual topping (MT). Recently, to replace MT in the Xinjiang cotton region of China, mepiquat chloride (MC) was applied once more than the traditional multiple-application; this was designated as chemical topping (CT), but it is unclear whether the amount of irrigation needs to be adjusted to accommodate CT. Results The main plots were assigned to three drip irrigation amounts [300 (I1), 480 (I2), and 660 (I3) mm], and the subplots were assigned to the CT treatments [450 (MC1), 750 (MC2), and 1 050 (MC3) mL·hm−2 25% MC] with MT as a control that was performed after early bloom. The optimum drip irrigation amount for CT was explored based on leaf photosynthesis, chlorophyll fluorescence, biomass accumulation, and yield. There were significant influences of drip irrigation, topping treatments and their interaction on chlorophyll fluorescence characteristics, gas exchange parameters and biomass accumulation characteristics as well as yield. The combination of I2 and MC2 (I2MC2) performed best. Compared with I2MT, the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and photochemical quenching coefficient (qP) of I2MC2 significantly increased by 4.0%∼7.2%, 6.8%∼17.1%, 5.2%∼17.6%, and 4.8%∼9.6%, respectively, from the peak flowering to boll opening stages. Moreover, I2MC2 showed fast reproductive organ biomass accumulation and the highest seed cotton yield; the latter was 6.6%∼12.8% higher than that of I2MT. Further analysis revealed that a 25% MC emulsion in water (MCEW) application resulted in yield improvement by increasing Pn, φPSII, and qP to promote biomass accumulation and transport to reproductive organs. Conclusion The results showed that the 480 mm drip irrigation combined with 750 mL·hm−2 MC increased the rate of dry matter accumulation in reproductive organs by increasing Pn, φPSII, and qP to improve photosynthetic performance, thus achieving higher yield.

Effect of inorganic and organic sources and levels of boron on growth, yield and quality of cotton (Gossypium hirsutum) under salt stress condition

Therefore, a simple, completely factorial randomized pot experiment was conducted during 2018 at pot culture yard, Department of Soil Science and Agricultural Chemistry, Annamalai University to evaluate the effect of organic and inorganic sources and levels of boron on growth and yield, quality attributes and uptake by cotton under salt stress condition. The experiment was conducted with four levels of boron (0, 0.5, 1.0 and 1.5 mg//kg of soil) through three sources viz., borox, solubar and magnesium borohumate complexes. The cotton variety LRA5166 was used as test variety. The results revealed that application of 1.5 kg of B through magnesium borohumate (MBH) complex recorded the higher plant height (124.6 cm), leaf area index (4.82), DMP (216 g/pot), yield components like number of bolls per plant (18.20), and mean boll weight (3.92) of cotton in saline sodic soil. Furthermore, higher seed cotton yield (93.51 g/pot), seed yield (54.72 g/pot) and lint yield (33.53 72 g/pot) were also recorded. This was on par with application of 1.0 kg of B through magnesium borohumate and recorded the plant height (122.81 cm), leaf area index (4.7), DMP (213 g/pot), yield components like number of bolls per plant (17.4), and mean boll weight (3.83 g), seed cotton yield (92.71 g/pot), seed yield (54.1 g/pot) and lint yield (32.96 g/pot) and followed by S2L4 (1.5 kg of B through solubar). The conclusion made from this study is the application of boron through 1.0 kg of B through magnesium borohumate will sustainably increase the cotton yield in saline sodic soil.

Bio-efficacy of Certain Insecticides Sequence on Cotton Sucking Pests and Pink Bollworm

The field trials were conducted for two consecutive years during kharif, 2018 and 2019 seasons in the Regional Agricultural Research Station, Warangal, Telangana, India. The susceptible hybrid RCH-2 was grown during both the years of study. Among the treatments, significant (25.4%) reduction of aphids was recorded in neem oil, clothianidin and flonicamid sequential spray. The sequence chlorpyriphos, flonicamid and clothianidin achieved superior efficacy against jassids with 32.3% reduction over control during the two seasons. The highest reduction (25.2%) of thrips was observed in neem oil, clothianidin, flonicamid sequential spray. The incidence of whitefly was low during the experimental period, however, the highest white fly reduction (15.0%) was observed in chlorpyriphos, flonicamid, clothianidin spray. The lowest number of PBW larvae per 10 green bolls was observed in profenophos, spinetoram, chlorpyriphos+cypermethrin sequential spray that reduces up to 61.9% incidence. The lowest number of (38.5) damaged locules per 100 fully opened bolls were observed in profenophos, spinetoram, chlorpyriphos+cypermethrin sequential spray. But, the highest seed cotton yield (1414 kg ha-1) as well as benefit cost ratio (1.02) was recorded in chlorpyriphos, flonicamid, emamectin benzoate, clothianidin, indoxacarb+acetamiprid sequential spray. The study further revealed that, initial control of sucking pests menace especially jassid was crucial in deciding the cotton yield as compared to later stage pink bollworm menace. During both the years, it was noticed that during peak incidence of jassid, the treated plot with flonicamid against jassid in first instance had given highest seed cotton yield.

PLANT SPACING AND ITS EFFECT ON YIELD, FIBRE QUALITY AND PHYSIOLOGICAL PARAMETERS IN COTTON

The purpose of this study was to see how changing plant spacings affected cotton yield, yield components, fibre quality traits, and physiological parameters. In this study, six plant spacings (no thinning, 5, 10, 15, 20, and 25 cm) were investigated. Plant density caused significant differences in the number of first fruiting branches, number of bolls, ginning percentage, seed cotton yield, fibre yield, and normalised difference vegetative index (NDVI). Plant height, the number of sympodial branches, number of monopodial branches, boll weight, seed cotton weight/boll, number of 100-seed weight, seeds/boll, canopy temperature, chlorophyll content, leaf area, and fibre quality properties (micronaire, length, strength, elongation, uniformity, short fibre index, reflectance, yellowness, and spinning consistency index [SCI] were non-significant. The highest values of seed cotton yield, fibre yield, ginning percentage, number of first fruiting branches, and NDVI were obtained in the no thinning and 5 cm plant spacing applications, while the highest boll number was obtained at 20 and 25 cm plant spacings. In this study, physiological parameters, such as canopy temperature, leaf area, chlorophyll content, and fibre technological traits, were not affected by plant spacing. The highest seed cotton yield, fibre yield, ginning percentage and NDVI were obtained from no thinning and 5 cm intra-row spacing, indicating their impact on examined characteristics. Therefore, a yield estimation can be made in the flowering period with the NDVI in different plant densities in cotton.

Drip fertigation improves seed cotton yield, water productivity and profitability of cotton raised under high density planting system in semi-arid environment

The wasteful system of flood irrigation being widely practiced for cotton production in India needs replacement by efficient irrigation systems for conserving water. Cotton productivity can be boosted by optimizing the nutrient and water application through modern resource conservation techniques. Therefore, a field experiment has been conducted during summer (Kharif) season of year 2016 and 2017 to investigate consequence of surface drip irrigation along with N fertilization on the growth and seed cotton yield (SCY) under recently introduced high density planting system (HDPS) in India. The experiment having combinations of 3 drip irrigation {60, 80 and 100% of crop evapo-transpiration (ETc)} and 3 N fertigation levels {125 (94 kg N), 100 (75 kg N) and 75% (56 kg N) of recommended N dose (RDN)} along with control (i.e. conventional practice of irrigation through surface flood and soil broadcasting of urea as 100% RDN i.e., 75 kg N ha-1) has been conducted in complete randomized block design replicated thrice. Drip irrigation scheduled at 0.8 ETc recorded 2.5 and 23.2% higher SCY (2509 kg ha-1) than 1.0 ETc and 0.6 ETc, respectively. Among N levels, highest SCY (2452 kg) was observed with 75 kg N application, whereas 56 kg N ha-1 recorded least. A combination of drip fertigation at 0.8 ETc and 100% RDN elucidated 11.6, 61.5, 13.9 %, and 42.9 % higher SCY, water use efficiency, nitrogen use efficiency and benefit: cost ratio than control, respectively. Drip fertigation at 1.0 ETc along with 100% RDN improved SCY by 7.3% over control.

Influence of Various Plant Spacing on Plant Population and Yields of Cotton (Gossypium Arboreum L.)

To boost output and lower cotton input costs, a narrow plant spacing production system has been proposed as an alternative to the conventional method. However, more examination through into performance of this production system in various parts of the world's cotton belt may be essential. The field experiment was conducted at Hill Cotton Research Station, Balaghata, Bandarban, Bangladesh during 2020-21 growing season to study the performance of SR 27 Cotton line ( Gossypium arboreum L.) beneath numerous plants spacing. The treatments consisted of four plant spacings viz. 90cm × 45cm, 90cm × 30cm, 90cm × 15cm, 90cm × 10cm. The experiment was carried out with a randomized complete block design and repeated 3 times. The highest seed cotton yield (2705kg/ha) and plant number (68107) per hectare, were recorded with spacing of 90cm × 10cm which was significantly( p<0.01 ) more than 90cm × 45cm, 90cm × 30cm and 90cm ×15cm. But, other parameters like plant height (cm), node number of first fruiting branch (NFB), number of monopodial branches/plant, number of sympodial branch/plant, number of bolls/plant and single boll weight (gm) were statistically non-significant but they play a role in yield. So that, narrow (90cm × 10cm) plant spacing is better than others wider plant spacing for getting maximal seed cotton yield and plant population play a key factor to minimize yield losses.

Evaluation of Insect Growth Regulators Against Leafhoppers and Whiteflies in BT Cotton

Studies were conducted to evaluate efficacy of insect growth regulators against leafhoppers Amrasca (Sundapteryx) biguttula, and whiteflies Bemisia tabaci (Gennadius) on cotton at the Department of Entomology, Dr. PDKV, Akola during 2019-2020. Overall four sprays were given out and the data obtained revealed that buprofezin 25%SC was found promising against leafhopper population. However, this treatment was found statistically similar to pyriproxyfen 10%EC and buprofezin 25%SC + NSKE 5%. The application of pyriproxyfen 10%EC, pyriproxyfen 10%EC + NSKE 5% and buprofezin 25%SC proved statistically equal in reducing whiteflies population. The treatments were found to be safe to the natural enemy activity. The highest seed cotton yield was obtained in the plots sprayed with buprofezin 25%SC (13.40 q/ha).

Determining Planting Window for Growing Upland Cotton (Gossypium hirsutum L.) during Dry Season in Bandarban, Bangladesh

Farmers in the Chattogram Hill Tracts, Bangladesh have been growing cotton (Gossypium hirsutum L.) in their traditional system of jhum cultivation which is undergoing transformation. Growing rainfed cotton as a monocrop in the uplands is constrained by farmers’ socio-economic conditions and erratic rainfall. Shifting growing season to post-monsoon dry monthscould be an option to sustain cotton production in hilly areas. An exploratory experiment was conducted for two seasons to explore the possibility of growing cotton in valley lands in Bandarban during dry season. Growth and yield potentials of dry season cotton were evaluated in relation to prevailing environmental conditions. Night temperature dropped to 9oC on several occasions in 2018-2019 season; but it remained higher than 11oC throughout the season in 2019-2020. In 2018-2019, day temperatures surged higher past March 15 occasionally exceeding 38oC. Variability in temperatures was more in 2018-19 while average temperatures were higher in 2019-20 season. Rainfall distribution was almost similar in both the growing seasons receiving total rainfall of 757 mm and 579 mm in two seasons, respectively. Higher seed cotton yield (2,047 kg per ha) was recorded for 15 November planted crop compared with 1 December planted crop (1,186 kg per ha). December 1 planted crop was affected more by low temperatures at seedling stage resulting in poor growth and fewer bolls per plant. Late planted crop was more vulnerable to rain damage at boll opening stage. Crops of both the seasons encountered high temperatures (&gt;32oC) during boll development. Changing climate, shorter winter season and rising temperatures may allow cotton production in valley lands shifting growing season from rainy season to post-monsoon dry months. However, the window of dry season cotton growing in Bandarban, Bangladesh seems narrow. Rainfall pattern restricts planting seeds prior to mid-November. Again, high temperatures stress in March and April synchronizing boll development, and rainfall toward late April and May during boll opening may cause yield loss. Development and adoption of short duration, low temperature tolerant upland cotton varieties might be of advantage for adapting to climate change vulnerabilities. Ann. Bangladesh Agric. (2020) 24(2): 1-14

Cotton phenology and production response to sowing time, row orientation and plant spacing using CROPGRO-cotton model

The DSSAT module for cotton crop has been evaluated as a tool to predict the crop growth and yield response to microclimatic modifications. In this context, multi-location field experiments were laid out at Bathinda and Faridkot, districts of Punjab during Kharif 2018 with Bt-cotton hybrid RCH 773 BGII and sown at three times, i.e., April 30, May 15 and May 30 with two row orientations (North-South : N-S and East-West : E-W) and three plant spacing’s (67.5 cm × 45.0 cm, 67.5 cm × 60.0 cm and 67.5 cm × 75.0 cm) in factorial split plot design and replicated by three times. The model output in terms of simulated phenology showed close proximity over observed value having R2 of 0.51 and 0.61 at Bathinda and 0.43 and 0.87 at Faridkot anthesis and maturity, respectively. Among study locations, observed and simulated LAI ranged from 2.7 to 3.7 and 1.8 to 3.0. Simulated seed cotton yield was found significantly higher with the crop sown on 30th April (3053 and 3274 kg ha-1) than 30th May sowing (2392 and 2511 kg ha-1) at Bathinda and Faridkot, respectively, which was in good agreement with observed yield having higher value of d-stat (0.84 for Bathinda and 0.89 for Faridkot) and R2 (0.75 for Bathinda and 0.83 for Faridkot). Moreover, higher seed cotton yield was simulated under East-West row direction along with wider plant spacing (67.5 × 75 cm) at both locations. Overall, CROPGRO-cotton model can be used as research tool for the prediction of cotton phenology and yield and to explore site-specific adoption strategies such as appropriate sowing time, row orientation and plant spacing to sustain cotton productivity under changing climatic conditions.