Effects Of Sowing Density On Seeding Quality And The Yield And Quality Of Rice

Effects of the growth, development, yield and quality on rice transplanting have been studied by the influence of 3 different sowing densities (60g/m2,180g/m2 and 300g/m2) on morphology, physiology and biochemistry rice seedling stage. The exprimend was working in practice base of Northeast Agricultural University from 2008 to 2009 and using Dongnong04-18 and Dongnong423 as testing varieties:1.Effect of the growth and development on rice seedling by different density has been study and the results showed that there were significant delay development in leafage at different density in both varieties. The rice seedling has a fastest development in 60g/m2.2. In all rice seedling stage, there were no significant differences in plant height at different density in both varieties. Leaf aera, root number, white root number, root growth ability and tiller showed an increasing trend with the decreasing sowing densitie.3.In 60g/m2, there were the most of dry matter accumulation and the highest plumpness. And there were significant improvement in content of soluble sugar, proline, sod and pod in 60g/m2.4. With the decreasing sowing densitie, the content of soluble protein increased in both varieties, and presented as the increased at first and then decreased trend in all rice seedling stage. So we could consided that the rice can have more available nitrogen and benefit to strong seedling culture.5. In 3 densities, root activity of rice plant presented as an increased at first and then decreased trend in both varieties. In Dongnong04-18, root activity in 60g/m2 was higher than the others and the treatments of 180g/m2 and 300g/m2 had no significant difference. In Dongnong423, root activity in 60g/m2 was higher than the treatments of 180g/m2 and 300g/m2,8.4% and 43.77% respectively.6. Under different cultivation conditions.with the reduction in sowing density the tillering period and vigorously tillering period have been moved up.There is not noticeable difference of heading period between conditions.The strong seeding with tillers has more ripe ear rate than the weak seeding without tillers.At the 60g/m2 treatment, two varieties have the most valid ear number, grains per spike and seed setting rate.The yield increase significantly.7. At different sowing densities treatment, dry matter accumulation of two varieties is significantly different after earing. Dry matter accumulation of Dongnong 04-18 and Dongnong 423 at 60g/m2 treatment is more than at the 180g/m2 and 300g/m2 treatment.During maturation period,economic coefficient of two varieties at 60g/m2 treatment are 52.43% and 53.14%,more than another treatment.8. The yield increase obviously with appropriate reduction of sowing density and the highest value shows at 60g/m2 treatment.The yield of Dongnong 04-18 is 10285.88 kg/hm2 at 60g/m2 treatment and increase 7.1% than 180g/m2 treatment,17.6% than 300g/m2. The yield of Dongnong 04-18 is 10687.79 kg/hm2 at 60g/m2 treatment and increase 10.9% than 180g/m2 treatment,20.8% than 300g/m2 treatment.9. Different sowing densities can affect the food nutrition of rice. The amylose contents of Dongdong 04-18 at 60g/m2 treatment is higher than the others treatments, the others treatments have no significant difference. The protein content of Dongdong 04-18 at 60g/m2 treatment is lower than the others treatments, the 180g/m2 and 300g/m2 treatments have no significant difference. Dongnong 423 has the same law. The results show that different quality of rice seeding significantly affect amylose and protein contents.10. Analysis on the RVA profile characters shows that the appropriate reduction of sowing density will increase peak viscosity, hot paste viscosity, breakdown value and peak time.