Study On High Efficiency High Quality And High-yield Cultivation Of "Tongbi No.6"

The orthogonal gyration combination design was used in this experiment with plant density, and N, P and K rates as the influencing factors. density showed the greatest affect on caster yield, followed in order by potassium nitrogen phosphate. Under the same or similar conditions of the trial location, the following combination of the factors ensured a stable yield of >2052.86 kg/hm²,plant density between 23214～24786 plants/hm², nitrogenous fertilizer between 216.72～250.11kg N/hm², phosphate fertilizer between 161.77～189.30kg P₂O₅/hm² and potassium fertilizer at 209.85～236.85 kg K2O/hm².Nitrogen showed the most significant effects on the seed oil contend, followed in order by potassium, phosphorus and density. In the same or th similar condition, the following combination of the factors ensured the oil rate of seeds >50.63%,plant density between 22302～24498 plants/hm², nitrogenous fertilizer between 122.76～147.96kg N/hm², Phosphate fertilizer between 171.97～196.42 kg P₂O₅/hm² and potassium fertilizer between 158.62～182.77kg/hm² kg K2O/hm².Potassium showed the greatest affects on oil production, followed in order by density, phosphorus and nitrogen.In the same or the similar condition, the following combination of the factors ensured the oil production >1042.01kg/hm²,plant density between 26052～28890 plants/hm², nitrogenous fertilizer between 180.36～213.39kg N/hm², Phosphate fertilizer between 169.57～193.72kg P₂O₅/hm² and potassium fertilizer between 189.97～222.52kg/hm² kg K2O/hm².Dry material accumulation can be expressed as Logistic function and Y=A+Bt+Ct2 function during the whole growing periods of castor. Dry material accumulate the most amount when plant density between 24000～30000 plants/hm², nitrogenous fertilizer between 180～270kg N/hm², Phosphate fertilizer between 150～225 kg P₂O₅/hm²and potassium fertilizer between 225～300 kg K2O/hm² .The planting density effects on the LAI of castor .The LAI increases along with the density increases during the whole periods. But fertilizer affects on the LAI is not so much.The castor function leaf decreases its chlorophyll content along with the planting density increasing, The chlorophyll content is the highest when nitrogen at 270kg/hm². But the effects of phosphate and potassium on the leaf's chlorophyll content are not obvious .The result showed that the photosynthesis speed and the stomatal conductance were tending to maximum positive correlation.