Estimation of Chinese Cabbage Yield As Affected by Planting Date and Nitrogen Fertilization for Spring Production, Poster Board #327

The average annual and winter ambient air temperatures in Korea have risen by 0.7 °C and 1.4 °C, respectively, during the last 30 years. The continuous rise in temperature presents a challenge in growing certain horticultural crops. Chinese cabbage and radish, two important cool season crops, may well be used as a model to study the influence of climate change on plant growth, because they are more adversely affected by elevated temperatures than warm season crops. This study examined the influence of transplanting time, nitrogen fertilizer level, and climate parameters [including air temperature, radiation intensity, and growing degree days (GDD)] on the performance of a Chinese cabbage cultivar (Chunkwang) during the spring growing season to estimate crop yield under unfavorable environmental conditions. In our study, plant dry weight was higher when the seedlings were transplanted on 15 April (168 g) than on 22 April (139 g). There was no significant difference in the yield when plants were grown with different levels of nitrogen fertilizer. The values of correlation coefficient (R²) between GDD and leaf number and between GDD and dry weight of the above-ground plant parts were 0.9818 and 0.9818, respectively. Nitrogen fertilizer did not provide a good correlation with the plant growth. Results of this study suggest that the GDD values can be used as a good indicator in predicting the above-ground biomass yield of Chinese cabbage.