Study On The Cultivation Model For High-yielding And Quality Of Y99 Cotton (Gossypium Hirsutum L.)

The effect of four factors of planting density, nitrogen, phosphorus and potassium onthe lint yield and fibre quality of Y99 (Gossypium hirsutum L.) was studied on the farm ofHuazhong Agricultural University, by adopting the four-factor second-order regressionwith orthogonal, rotatable and central composite design, under transplanting condition, tofind out the optimum cultivation model for high-yielding and quality. The results showedthat:1. Nitrogen and phosphorus affected lint yield significantly in power function and theirinteraction on lint yield was extremely significant. The influence order on lint yield of thefour factors was: phosphorus (x₃)＞nitrogen (x₂)＞density (x₂)＞potassium (x₄). Theoptimized cultivation measures for lint yield beyond 1650kg/hm² included 27000-30000plants/hm² in density, 270～360kg/hm² of nitrogen, 135～180kg/hm² of phosphorus, and144～288kg/hm² of potassium.2. Nitrogen affected boll weight extremely significantly in power function, butphosphorus and potassium affected boll weight significantly in the same way, and theinteraction of'density and phosphorus on boll weight was significant. The influence orderon boll weight was: potassium(x₄)＞density(x₁)＞phosphorus(x₃)＞nitrogen (x₂). Theoptimized cultivation measures for boll weight beyond 5.8g were:24000～27000plants/hm² in density, 90～270kg/hm²of nitrogen, 45kg/hm² of phosphorus,72～144kg/hm² of potassium.3. Nitrogen affected bolls/hm² extremely significantly in power function, density andphosphorus were almost linear correlated to bolls/hm² positively, and their interaction onbolls/hm² was significant extremely. The influence order on bolls/hm² was: nitrogen(x₂)＞density(x₁)＞phosphorus(x₃)＞potassium(x₄). The optimized cultivation measures forbolls/hm² beyond 800,000 were 33000～36000 plants/hm² in density, 90～180kg/hm² ofnitrogen, 180kg/hm² of phosphorus, 72～288kg/hm² of potassium.4. No significant impact of the four factors on lint percentage was existed.5. Again, no significant effect was found on 5 main items of fibre quality.6. Therefore, the optimized cultivation model for high-yielding and high-quality ofY99(Gossypium hirsutum L) was 24000～27000 plants/hm² in density, 180～270kg/hm² ofnitrogen, 45～90kg/hm² of phosphorus, 72～144kg/hm² of potassium. Or that would be24000-27000 plants/hm² in density, 90～270kg/hm² of nitrogen, 45kg/hm² of phosphorus,72～144kg/hm² of potassium, if cotton is grown in the soil with a higher fertility withbetter irrigation and drainage system, otherwise, the planting model would be 33000～36000plants/hm² in density, 90～180kg/hm² of nitrogen, 180kg/hm² of phosphorus,72～288kg/hm² of potassium.