Effects of Different Densities on the Plants Morphology and Yield of Edible Sunflower in Ta′e Reclamation Area

In order to screen edible sunflower varieties and planting density suiltable for Ta′e Reclamation Area, a two-factor random block test of varieties and density was carried out in Ta’e Reclamation Area.And 3 varieties were set up in the main area, namely Tongqing 5,Jinhe 8, Tonghui 32, and four density levels were set for the secondary area treatment, which were M₁ treatment(29 000 plants·ha^-1) and M₂ treatment(33 300 plants· ha^-1), M₃ treatment(37 500 plants·ha^-1) and M₄ treatment(41 600 plants·ha^-1). The effects of four density levels on yield and plant morphology of different varieties were analyzed. The experimental results showed that the variety and density had significant effects on the weight of a single disc, the weight of 1 000 grains, the setting rate, the diameter of the flower disc and the yield. The yields of the three sunflower cultivars showed a trend of first increasing and then decreasing with the increase of density level, and the yield reached the highest level under the treatment of 33 300 plants·ha^-1（M₂）. The maximum yield of Tongqing 5, Jinhe 8 and Tonghui 32 were 4 027.53, 4 063.26 and 3 956.19 kg·ha^-1 respectively.Plant height and seed kernel rate increased with the increase of the planting density. The grain width, single disc grain weight and 1 000-grain weight all decreased with the increase of planting density, and reached the maximum at M₁ planting density(29 000 plants·ha^-1). On the whole, Jinhe 8 and Tonghui 32 are preferentially selected for planting in Ta′e Reclamation Area, the optimal density is 33 300 plants·ha^-1.