Effects of Different Sowing Dates on the Yield and Grain Quality for Super Rice 'Liangyou 616'

With super rice‘Liangyou 616'as material,effects of different sowing dates on the yield and grain quality were analyzed.The results showed that the yield of Liangyou 616'was declined gradually with low grain number per spike and seed setting rate postponing the sowing date.Among five different sowing dates,the highest yield of Liangyou 616'was gained on 4th June,and the lowest on 6th July.Liangyou 616'showed good grain quality and high scores of physicochemical properties indices under all sowing time treatments,the highest score appeared sowing on 6th July.Seven indices of Liangyou 616',including brown rice rate,polished rice rate,head milled rice rate,translucent endosperm,alkail value,del consistency and amylose content,all reached high quality standard under all treatments.It was also showed that milled rice rate and the scores of physicochemical properties of Liangyou 616'were increased,and the chalkiness ratio was decreased with the delayed sowing date and the low average temperature of grain-filling stage.Therefore by reasonably late sowing of Liangyou616'to control the temperature of rice grain-filling stage,the yield and grain quality could be both improved in large-scale production of‘Liangyou 616'.