Growing cotton in China.

This chapter focuses on the current status of cotton production in China and the genetic improvement and use of Bt transgenic cotton cultivars in the country. Some major insect pests, weeds and diseases of cotton in the country are presented and the efficacy of various methods used in their management are highlighted. Some information on the cultivar selection, cultivation methods, harvesting technologies and fibre quality characteristics of cotton in the country are also discussed.

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.

Soil application of boron impacts its solubility, yield and fibre quality of cotton in calcareous soils of North-western India

Aim: To investigate that application of boron (0-2.5 mg kg-1 soil, as borax and granubor) to calcareous soil in North-western India affectes its solubility in soil, yield and fibre quality characters of cotton (Gossypium hirsutum L.). Methodology: A field study was conducted to estimate and enumerate the influence of B application (as borax and granubor @ 0-2.5 mg B kg-1 soil; B0-B2.5) on cotton yield and yield contributing attributes ascribed to change in different fractions of variable solubility in B deficient (available B=0.21 mg kg-1) calcareous sandy loam soil. This field experiment was set up in a plot size of 2.7m X 3.75 m with three replications arranged in RBD in factorial combinations. Results: Mean lint and cotton seed yield increased significantly under B1.0, compared with control (B0). Boron concentration in roots, leaves, petioles, bolls, sympodial and monopodial branches, seeds and lint increased significantly (p<0.05) with 1.0 mg B kg-1 application (B1.0). Boron application (B2.0) significantly augmented the mean uniformity ratio by ~4.8%, compared with B0, while the fibre strength and staple length increased significantly in B1.5 treatment. The micronaire value of lint decreased significantly from 4.84 (in B0) to 4.25 µg inch-1 in B2.5 treated plots. Boron application caused notable augmentation in B concentration in its reservoirs/pools of variable solubility; oxide bound fraction being smallest (~0.34% of total B), while residual B the largest fraction (~95% of total B). Boron sources had meagre affect and did not vary remarkably for B concentration in different vegetative plant parts, cotton yield and contributing attributes and B fractions of variable solubility in calcareous soil. Interpretation: The findings of study divulged that soil applied B significantly augmented cotton yield and its yield contributing attributes owing to augmented solubility of B in a calcareous soil. Different B fractions evinced a significant (p<0.05) relationship with yield attributes, indicating their significance for increased B uptake which impacts the seed cotton yield in a calcareous soil. These experimental outcomes highlight the overwhelming significance of soil application of B for increased cotton productivity with improved fibre quality.

Cotton Stalk Compost as a Substitution to Farmyard Manure Along with Mineral Fertilizers and Microbials Enhanced Bt Cotton Productivity and Fibre Quality in Rainfed Vertisols

Cotton stalks, remaining after the cotton is harvested, are considered waste material and disposed of by burning. Presently, the supply of good quality manure, such as farmyard manure (FYM) is low. Thus, recycling of cotton stalks as compost can reduce the dependency on FYM apart from reducing inorganic fertilizer use and soil health enhancement. Some studies have reported on the conversion of cotton ginnery wastes into organic manure. However, no studies have reported about the composting of cotton stalks. We conducted field studies over three years on Vertisols to evaluate the impact of integrated use of microbially enriched cotton stalk compost (ECC) as an alternative to FYM along with mineral fertilizers in cotton production. Additionally, we evaluated an option of using native microbial consortia as seed treatment and their synergistic effect along with ECC application on cotton yield, fibre quality, and soil properties. Results indicated that the substitution of FYM with ECC in integrated nutrient management (INM) produced effects similar to that of FYM use in enhancing cotton yield and soil properties. Application of ECC + inorganic fertilizers (modified nutrient management practice) in soil increased boll numbers (8.4%), boll weight (9.9%), seed cotton yield (13%), fibre properties, soil nutrient, and biological activities, which were on par with FYM + inorganic fertilizer application. The use of ECC is estimated to reduce 50% costs on nitrogenous, phosphatic, and potassic fertilizers, and can save approximately US$ 34 ha− 1 on inorganic and manures in the recommended dose of fertilizers (RDF) and INM practice.

Assessment of production potential of long-linted Gossypium arboreum L. genotypes under different sowing times

Background Gossypium arboreum is one of the cultivated diploids which has inherent resistance against insect pests and diseases, can withstand moisture stress, needs less nutrients and is suitable for erratic, less rainfall and marginal soils. Due to its smaller boll size and poor locule retentivity, adoption of species by farmers is very low. So, best long-linted G. arboreum genotypes with high yielding potential and suitable sowing time will be identified for rainfed tracts of cotton cultivated areas in India. Results The pooled analysis results found that the significantly highest mean seed cotton yield was recorded with Phule Dhanwanthry (1069 kg/ha) which was on par with K12 (1027 kg/ha), DLSA 17 (977 kg/ha) and PA 812 (951 kg/ha). Planting at 4 August yielded the significantly higher seed cotton yield (1345 kg/ha) in comparison with 4 September sowing (536 kg/ha). The interaction results in pooled data revealed that Genotype PA 812 planted at 4 August registered the significantly highest seed cotton yield (1487 kg/ha) which was on par with all genotypes sown on 4 August except PA 402. Amongst long-linted genotypes, PA 760 recorded the significantly highest upper half length (29.9 mm), mean length (24.9 mm) and fibre strength (27.0 g/tex) and fibre quality index (349.7); which was on par with DLSA 17, PA 812 and PA 402. The quality characters had not been influenced significantly by different times of sowing. Conclusions The results concluded that the significantly highest mean seed cotton yield was recorded with Phule Dhanwanthry (1069 kg/ha) which was on par with K12 (1027 kg/ha), DLSA 17 (977 kg/ha) and PA 812 (951 kg/ha). Planting at 4 August found that the significantly higher seed cotton yield (1345 kg/ha) in comparison with 4 September sowing (536 kg/ha). Amongst long-linted genotypes, PA 760 recorded the significantly higher fibre quality index (349.7)