Nutrient and irrigation water on leaf reddening in Bt hybrid 6 cotton in calcareous substrata soils

摘要

Programmable RGB sensor was used for prediction of nutrients need of BG II Hybrid-6 cotton and found R2 value of 0.98 for nitrogen topdressing at the end of September month. Recommended dose of fertilizer nutrients (RDF 90:45:45 kg/ha N:P205:K20) weresufficient to produce profitable yields with highest water and fertilizer use efficiency in both station and farmer's fields. Validation of it in Calcareous soil farmer's fields (2016) found it had a satisfactory boll size of 5g and competitive with many private commercial hybrids with a lint yield level of 450 kg/ha. Leaf reddening was significantly reduced with supplemental irrigations only in a year of seedling droughts.