Abstract:To understand the effects of rates of nitrogen and potassium on the growth and yield of potato varieties of ‘Favorita’, this study used five treatment with 0, 75, 150, 225 and 300 kg/hm2 nitrogen and five treatment with 0, 75, 150, 225, 300 kg/hm2 K2O to the plant in the southern winter paddy field. The results showed that the leaf chlorophyll content increased with the increase of nitrogen application rate, and the SPAD value was positively correlated with the increase of nitrogen application rate, while the correlation with the increase of potassium application rate was not significant. The results also indicated that the plant height and stem diameter were increased with the increase of nitrogen application rate during tuber initiation and the tuber bulking. There were significant positive correlations between plant height and stem diameter with nitrogen application rate, but the correlation with the increase of potassium application rate was not significant. The dry weight of total plant, above-ground and under-ground parts of potato plant increased with the increase of nitrogen application rate during tuber maturation. There were significant positive correlations between the dry weight with nitrogen application rate, and the correlation with the increase of potassium application rate was not significant. The yield of potato increased with the increase of nitrogen application rate, and the average yield was the highest with 28 707.25 kg/hm2 at 225 kg/hm2 nitrogen treatment. There were significant positive correlations between potato yield, the weight of individual tuber, number of tubers per plant with nitrogen application rate, and significant negative correlation between dry matter content and nitrogen application rate. There was no significant correlation between the potassium application rate with the potato yield, marketable tuber rate, the number of tuber per plant, mean tuber weight and the dry matter content.