In order to provide the basis for sunflower production,taking Jingkui 809 B as test material,using randomized block design method,the effects of planting density on yield and agronomic characteristics of sunflower were studied.The results indicated that disc diameter reduced gradually;yield increased,plant height and 100-kernel weight increased first and then decreased with planting density increased.The commodity was the best in the density of 37 500 plant/hm~2.It could draw the conclusion that a reasonabl...