Abstract: To explore the effects of row distances on yield of different japonica rice cultivars with different types under drill seeding,with three different panicle types of japonica rice cultivars Tonghe 833,Tiejing 7,Shendao 506 as entries,the effect of five row distances on yield as well as physical properties and morphological characteristics of rice clum and panicle at milk (after heading stage 25 d)and dough stages(after heading stage 40 d),the two lodging sensitive stages,were studied under drill seeding condition. The results showed that with row distances changing the competition between the rows and in row was affected in the rice growth and development,which affecting the physical properties and morphological characteristics of plant,changing population structure,and eventually determining yield and lodging. As to Tonghe 833,the curved panicle cultivar,the highest yield appeared at 22.5 cm row distance,but with row distance decreasing,the productive panicle,seed setting rate and yield decreased meanwhile,in low row distance the between-row competition occurred fiercely,resulting in shading population,poor growing,decreasing breaking resistance between nodes and easy lodging; Tiejing 7 obtained the highest yield and stronger lodging resistance when the row distance was 17.5 cm; when at 20.0 cm row distance,Shendao 506 coordinated the competition in the row and between row,the individual plant grew well and the reasonable population structure was formed and the high yield and lodging resistance were realized. Briefly,too wide or too narrow row distance increased the competition between row and in the row,thereby affecting the physical properties of individual of plants,growth population structure,grain yield and lodging resistance. Above knowable,the seeds of curved panicle cultivars should be sown at larger row distance (22.5 cm),erect panicle cultivars at smaller row distance (17.5 cm),and semi-erect panicle cultivars at medium row distance (20.0 cm),and the high yield and lodging resistance could be easily reached through coordinating the competition between rows and in the row to ensure more productive panicles per unit area and higher seed setting rate,to improve breaking resistance and bending moment,and to build a reasonable individual plant morphology and population structure.

Key words: Drill seeding, Japonica rice, Row distance, Yield, Lodging resistance

CLC Number: 

• S314

• S511.01