Effects Of NH₄⁺/NO₃ On The Plant Growth And Tuber Development Of Potato

China is the main production country of potato and Inner Mongolia Autonomous Region is one of the important bases.Maximizing the use of nitrogen fertilizer,achieving the high yield and obtaining the good quality are significant in the potato production.In this study,virus-free tubers of Jizhangshu 12 were planted in pots under different proportions of ammonium nitrogen and nitrate nitrogen.By measuring the morphological index,sugar contents and dry matter contents of each parts in potatoes,the role of nitrogen proportion on the growth and development was determined and the suitable ratio of NH4+/NO3-was selected for the future production.The results showed that:1.With the development,plant heights,plant widths and leaf numbers increased gradually under NH4+/NO3-treatments,and the values under 7:3 of NH4+/NO3-were the highest in potatoes.They were 110.25,64.33 and 16.78 cm at the end of sampling.It showed that application of ammonium nitrogen enhances the growth and development of plants.2.With the plant growth,the number of stolons and of apical expansion increased gradually.The number of stolons and of apical expansion were the highest when NH4+/NO3-was 3:7.They were 10.9 and 8.1 per plant at the end of sampling.3.With the development,the contents of glucose,fructose,sucrose and starch in potato leaves showed a single peak change,which first increased and then decreased.The peaks were on the July 20th.The values were 15.00,12.65,58.89 and 7.68mg/gDW,respectively.The above indexes were the highest when NH4+/NO3-was 7:3.It indicated that reasonable application of ammonium nitrogen enhances carbohydrate synthesis in potato leaves.4.With the development,the content of glucose,fructose,sucrose and starch in potato stolons increased gradually.The final values were 25.19,22.95,18.11 and 10 mg/gDW.The above indexes were the highest when NH4+/NO3-was 3:7.It indicated that reasonable application of nitrate nitrogen promotes the growth and development of potato stolons.5.The dry matter content of each organ of potatoes showed a trend of increasing gradually.When NH4+/NO3-was 7:3,the average dry matter contents of single plant leaves and of single plant stem were the highest.They were 26.6%and 8.7%,respectively.When NH4+/NO3-was 3:7,the dry matter content of tuber per plant was the highest.The results showed that the ammonium nitrogen fertilizer promoted the above ground stem and the nitrate nitrogen promoted the underground stem.