Effects of sowing date and density on yield and lodging resistance of preci-sion hill-direct-seeding rice
To explore the effects of sowing date and density interaction on yield and lodging resistance of precision hill-direct-seeding rice in western Chongqing,Yuxiangyou 8133 and Taiyou Yuehesimiao were used as experimental materials.Two sowing dates(B1:March 29,B2:May 25)and five sowing densities(D1:1.50×105 holes per hectare,D2:1.95×105 holes per hectare,D3:2.40×105 holes per hectare,D4:2.85×105 holes per hectare,D5:3.30×105 holes per hectare)were set.The relationship between stem mechanics,stem morphology,organ dry matter accumulation and plant lodging resistance and yield was analyzed.The results showed that compared with the early sowing treatment(B1),the late sowing treatment(B2)could significantly increase the yield of precision hill-direct-seeding rice.At the same time,higher leaf area index(LAI)and effective panicles under B2 treatment led to a significant increase in stem lodging index.With the increase of planting density,the yield of the two rice varieties increased first and then decreased.The yield in D3 treatment was the highest under B1 sowing date.The yield in D4 treatment was the highest under B2 sowing date,but there was no significant difference with the yield in D3 treatment.Moreover,the lodging index showed a continuous increasing trend,and the two rice varieties had the same trend.Compared with D1 treatment,the lodging index in D2 and D3 treatments under B1 and B2 sowing date treatments increased slightly,and the lodging index in D4 and D5 treat-ments increased significantly,especially for Yuxiangyou 8133.Under B1 and B2 sowing dates,the stem and sheath dry weight per plant,basal internode stem diameter,wall thickness and stem and sheath plumpness in D2 and D3 treatments were com-parable to those in D1 treatment,but decreased significantly in D4 and D5 treatments.The comprehensive analysis results showed that D3 treatment was the suitable sowing density for the yield and lodging resistance of precision hill-direct-seeding rice under B1 and B2 sowing dates.
万方数据
维普
