Effects of different nitrogen forms on potato growth and development

Abstract

The objective of this study was to test if the effects of different nitrogen forms on potato growth depend on the plant growth stage. Plants from different potato cultivars were treated with different forms of nitrogen before tuber initiation and after tuber formation. A nitrification inhibitor was used to prevent the transformation of ammonium (NH4+) to nitrate (NO3−). Plant growth, tuber formation, leaf area, leaf chlorophyll content, and tuber yield were assessed. The results obtained over 2 years indicate that plants treated with NO3-nitrogen (N) before or at tuber initiation produced more tubers per plant than those treated with NH4-N. However, plants treated with NH4-N develop tubers earlier. Additionally, after tuber formation, plants treated with NH4-N had better shoot growth than plants treated with NO3-N. A larger leaf area with higher leaf chlorophyll content resulted in greater dry matter accumulation and higher tuber yield at harvest for plants treated with NH4-N.