Contribution of total nitrogen content in storage roots to multiple regression analysis for estimating yield of asparagus in rootstock-planting forcing culture
Rootstock-planting forcing culture is used in Japan to harvest asparagus spears out of season. To assess the yield before the actual harvest, we performed a multiple regression analysis using yield as a dependent variable and rootstock weights, chilling hours (i.e., cumulative hours during which the air temperature remained lower than 5°C), Brix values of storage roots, and total nitrogen content of storage roots as independent variables. Our previous study showed that rootstock weights and chilling hours were significant as independent variables. The addition of the nitrogen content of storage roots as an independent variable in the present analysis caused the multiple correlation coefficient to increase significantly (p=0.05). The possible role of nitrogen content in yield estimation is discussed.
Uragami, A., Ueno, R., Matsuo, K., Yamaguchi, T., Sakai, H., Motoki, S., Takizawa, T., Tokiwa, H., Ikeuchi, T., Watanabe, S., Shinzato, Y., Matsunaga, K., Kitazawa, H. and Yamasaki, A. (2018). Contribution of total nitrogen content in storage roots to multiple regression analysis for estimating yield of asparagus in rootstock-planting forcing culture. Acta Hortic. 1223, 73-80
Asparagus officinalis L., yield estimation, chilling hours, total N content, rootstock-planting, forcing culture