The Influences Of N Forms And PH On Potato Tuber Growth

To research the effects of N forms on potato tuber forming organs growth and further study the involvement mechanism, a local potato cultivar Kexin-I and Shepody were the aimed materials. Two or three nitrogen forms (NO3-, NH4+, or NO3-NH4+=50:50) were applied in the pot sand culture experiments in greenhouse from2010to2011. The plant dry matter accumulation and distribution, tuber forming organs morphology and plant nitrogen absorption and distribution during the plant development were studied. One year experiment with different pH treatment conducted in2012. The results followed as:1During the tuber forming period, NO3-benefited for plant dry accumulation and the photosynthetic production rate, so NO3-stimulate the tuber forming; after tuberization, NH4+started stimulated the plant dry matter accumulation, the leaf area and plant height, as well as photosynthetic production rate, sink strength and per tuber bulking rate, and NH4+was benefit for tuber bulking compared with NO3-.2Plant fresh weights were increased with pH increased, Kexin-Ⅰ cultivar stolon length were increased with pH increased, however, there was only significant difference between pH3.8and pH6.8, it showed that potato could adapt a wide pH scope, and the difference of potato plant growth caused by NO3-and NH4+was due to the changes of rhizosphere pH changes after NO3-and NH4+absorption by plants.