Effects Of Planting Density And Chemical Regulation On Agronomic Characters,Yield Of Tigernut(Cyperus Esculentus L.)

The development of tigernut(Cyperus esculentus L.)industry is of great significance to alleviate the pressure of China’s heavy dependence on imports of oil crops.In this experiment,three plant density treatments were set:20.85×10~4 plants/hm~2(D1),15.60×10~4 plants/hm~2(D2),12.00×10~4 plants/hm~2(D3)and three chlormequat chloride concentrations(CCC):0 mg/L(C0),1500 mg/L(C1)and 2500 mg/L(C2)were used to analyze the effects of different treatments on plant height,tiller number,biomass,tuber phenotype,yield,composition factors and crude fat content of tigernut and to reveal the suitable planting density and the spraying concentration of CCC.The aim of this study is to provide theoretical and practical basis for the efficient cultivation of tigernut in arid oasis of Xinjiang.The main research results are as follows:1.The agronomic traits of tigernut were affected by planting density and CCC.The plant height and leaf area index of decreased significantly with increasing planting density,while the number of tillers,leaf length and leaf number decreased significantly,but the leaf width did not decrease significantly.With the increase of spraying concentration of CCC,plant height and leaf length decreased significantly,plant height decreased by 6.15%～11.87%,tiller number,leaf width and leaf area increased,while leaf number increased significantly.2.With the increase of planting density,the biomass of aboveground and underground parts of tigernut decreased significantly,and decreased by 32.66%～35.10%and 27.68%～32.57%respectively at maturity.After spraying concentration of CCC,the aboveground biomass increased gradually,while the underground biomass increased first and then decreased,which showed C2(91.97 g/plant)>C0(89.60 g/plant)>C1(81.58 g/plant),and the difference between C2 and C1 was significant.With the increase of planting density,the 1000 grain weight decreased gradually,the number of grains per hole,the total number of grains and the actual yield decreased significantly,and the theoretical yield increased first and then decreased,showing a trend of D2>D3>D1.With the increase of spraying concentration of CCC,the number of seeds per hole and the total number of seeds decreased by 8.65%～21.17%.The 1000 grain weight increased by 0.15%～3.48%,but the increase was not significant.The theoretical yield and actual yield of spraying CCC were lower than that of the control,and the theoretical yield decreased significantly in D2 and D3 planting density.3.In the range of length<11 mm,width<9 mm,area<78 mm~2 and roundness<0.8 mm,the number of tubers increased with the increase of planting density,while the content of crude fat decreased significantly.Spraying CCC at C2 concentration increased the number of tuber grains in the grading range of tuber length>11 mm,width>9 mm,area>78 mm~2 and roundness>0.8 mm,which showed C2>C0>C1,while the crude fat content in D1 and D3 was C2>C1>C0,with extremely significant difference.The results showed that the growth and development of tubers were limited and the number of small tubers increased under D1planting density.Spraying CCC increased the weight of tubers,which indicated that chemical regulation was an important factor for close planting and stable yield.In general,under the condition of this experiment,the yield of tigernut was the highest under D2 planting density,and the crude fat content was the highest under C2 treatment.Therefore,under the conditions of planting density 15.60×10~4 hole/hm~2(D2)and 2500 mg/L(C2),the high yield and good quality of tigernut can be achieved in arid oasis farmland.