Effects Of Sowing Methods And Sowing Dates On Material Accumulation,Translocation And Yield Of Direct-seeded Rice

In order to explore the suitable sowing method and date of direct-seeded rice in Jilin Province,the field experiments were used to select three early-maturing varieties with better germination indicators at low-temperature germination tests,Baigeng 1,Changbai 9 and Longgeng 31 as test materials;two kinds of seeding methods: hole-seeding and drill-seeding;set three sowing dates,namely Ⅰ(May 5),Ⅱ(May 10),Ⅲ(May 15).In the experiments,the changes of direct seedling rice growth period,stem borer dynamics,dry matter and nitrogen accumulation and transportation in various organs after anthesis,content of stem and sheath chemical components,yield and yield components under different sowing methods and dates were studied.The main results were as follows:1.Along with the delayed sowing date,under conditions of hole-seeding and drill-seeding,the whole growth period of three varieties became shorter gradually decreased,and the number of days from sowing to jointing and from jointing to heading gradually decreased,but the number of days from heading to maturity gradually increased.2.The dynamics of stalk borer in hole-seeding and drill-seeding increased first and then decreased.The numbers of stem borer in each stage of hole sowing treatment was higher than that at the same sowing date of hole sowing treatment.Along with the delayed sowing date,under conditions of hole-seeding and drill-seeding,the numbers of stem tillers of three varieties wereⅡ>Ⅲ>Ⅰ.3.Under different sowing methods,the total dry matter accumulation in the shoots of Baigeng 1,Changbai 9 and Longgeng 31 at the heading stage in hole-seeding treatment was 21.73%,20.87% and 13.66% higher than the drill-seeding treatment,the total dry matter accumulation in the shoots of Baigeng 1,Changbai 9 and Longgeng 31 at the maturity stage in hole-seeding treatment was 20.27%、16.18% and 11.95% higher than the drill-seeding treatment.The dry matter translocation amount and dry matter translocation efficiency of hole-seeding treatments at the same sowing date were all higher than those in drill-seeding treatments.Along with the delayed sowing date,under hole-seeding treatments,the dry matter accumulation of all organs and the total dry matter accumulation of above-ground in the two growth periods showedⅡ>Ⅲ>Ⅰ.Under drill-seeding treatments,the dry matter accumulation of in each organ and the total dry matter accumulation of above-ground in the two growth period of Baigeng 1 and Longgeng 31 wereⅡ>Ⅲ>Ⅰ;the dry matter accumulation of stem-sheath and panicle and the total dry matter accumulation of Changbai 9 during the two growth period wereⅡ>Ⅲ>Ⅰ,along with the delayed sowing date,the accumulation of leaf during the two growth period decreased generally;the amount of dry matter translocation and dry matter translocation efficiency wereⅡ>Ⅲ>Ⅰ.4.Under different sowing methods,the total nitrogen accumulation in the shoots of Baigeng 1,Changbai 9 and Longgeng 31 at the heading stage in hole-seeding treatment was 19.58%,22.94% and 22.40% higher than the drill-seeding treatment,the total nitrogen accumulation in the shoots of Baigeng 1,Changbai 9 and Longgeng 31 at the maturity stage in hole-seeding treatment was 16.17%、15.26% and 14.16% higher than the drill-seeding treatment.The nitrogen translocation amount and nitrogen translocation efficiency of hole-seeding treatment in the same sowing date were all higher than those in drill-seeding treatments.Along with the delayed sowing date,under hole-seeding and drill-seeding treatments,the nitrogen accumulation in each organ and the total nitrogen accumulation of above-ground in the two growth periods wereⅡ>Ⅲ>Ⅰ.The amount of nitrogen translocation and nitrogen translocation efficiency were Ⅱ>Ⅲ>Ⅰ.5.The cellulose content,hemicellulose content and relative lignin content of the stalks at the heading stage were higher than those of the same sowing date at maturity stage.Under different sowing methods,the cellulose content,hemicellulose content,and relative lignin content of the stalks of above-ground in the two growth periods were higher in the hole-seeding treatments than those at the same sowing date in the drill-seeding.Along with the delayed sowing date,under the hole-seeding and drill-seeding,the cellulose content,hemicellulose content and relative lignin content of the stalks at heading stage and maturity stage showedⅡ>Ⅲ>Ⅰ.6.Under different sowing dates,the yield of hole-seeding was higher than that at the same sowing date under drill-seeding,Baigeng 1,Changbai 9 and Longgeng 31 increased their yields by 25.90%,24.70% and 24.87% on average,respectively.Along with the delayed sowing date,under both hole-seeding and drill-seeding treatments,the yield was highest at the sowing date II.Delaying the sowing date increased the effective panicle number and seed setting rate,but reduced the number of grains per panicle,and the 1000-grain weight variation trend was inconsistent.In summary,the group structure of the hole-seeding treatment was reasonable,and the material accumulation and yield were better than the drill-seeding treatment.The yield,material accumulation and trans-location were decreased when sowing date was early or late.The hole-seeding method was more suitable for direct-seeding rice cultivation than the drill-seeding method in Jilin Province.The second sowing date was suitable sowing period.