Effects Of Nitrogen Management On Potato Tubers Growth And Development

Kexin13was used as the test material,with five treatments.The five treatments were as followed:120kg N ha-1at planting and60kg N ha-1at the early tuber bulking stage (T1),90kg N ha-1at planting and90kg N ha-1at the end tuber formation stage (T2),90kg N ha-1at planting and90kg N ha-1at the early of tuber bulking stage (T3),60kg N ha-1at planting and120kg N ha-1at the end of tuber formation stage (T4),60kg N ha-1at planting and120kg N ha-1at the early of tuber bulking stage (T5).To study the effect of nitrogen fertilizer application time and promotion on the distribution of different set of potato tuber as well as the nutrient and dry matter accumulation and distribution in different set potato tuber.The aim of the study is to put forward suitable nitrogen management strategies of potato production for different usage of potato tuber and the main results are as follows:From the tuber formation beginning, potato tuber dry matter accumulation show a continued growth trend, and tuber dry matter in the proportion of whole plant also increased. With the same amount of nitrogen application, the application time of nitrogen fertilizer can increase tuber dry matter accumulation and the distribution proportion in tubers at harvest. The ratio of dry matter distributed more than75g at harvest accounted for about3/4of potato tuber yield. Potato tubers ranged from1OOg to150g had the higher dry matter than other grades.NPK accumulation of potato tubers which have been increasing,since the beginning of tuber formation,to the highest in harvest period. The highest harvest of T2NPK accumulation, respectively is308.68kg/hm2,68.2kg/hm2,252.41kg/hm2. The tuber nitrogen content of T2was higher than other treatments for2.52%;50DAE fertilizer treatment tuber phosphorus volume increased slightly in the harvest period,but the difference between treatments was not obvious; the potassium content of the tubers in the early formation was the highest, and then decreased slowly. The harvest of potato tuber,75g≤W<100g level tuber nitrogen and phosphorus content higher than other levels of tuber. The content potassium of tubers with high content of more than100g.Tests showed that a reasonable application of nitrogen fertilizer can increase the number of tubers per plant and average tuber weight effectively increase potato production, production of T2is23.71t/hm2,commodity potato rate and commodity potato were83.48%and19.79t/hm2,higher than the other four.T2have a greater harvest index,and performance0.71.Tuber yield different level is100≤W<200g production output accounts for about1/2.Tuber starch content was higher in75-250g.