S08 - Session P4 - Growth and accumulation of secondary metabolites in basil as affected by light spectrum and applied nutrient amount in nutrient solution

Authors: Xiaowei Ren, Na Lu *, Wenshuo Xu, Yunfei Zhuang, Michiko Takagaki

The growth and accumulation of secondary metabolites of vegetables are affected by integrated environmental conditions such as light spectrum and nutrient supply. Quantitative fertilizer management has advantages, such as saving resources and improving nutrient utilization efficiency, compared with the conventional electrical conductivity management method. In this study, we investigated the effects of light spectra with different R:B ratios (3:7, 7:3, and 9:1) and the quantitative fertilizer management (applying different nutrient amounts: 1/2, 1, and 2 times of absorption amount, represented by 1/2T, 1T, and 2T, respectively) of nutrient solution on the growth and accumulation of secondary metabolites of basil plants in a plant factory. The results showed that there was no significant difference in leaf fresh and dry weight among the applied nutrient amount conditions, however, the antioxidant capacity and total phenolic content were significantly increased by the treatment of 1/2 T as compared to treatments of 1T and 2T, regardless of R:B ratios. On the other hand, under the treatment of 1/2 T, an R:B ratio of 7:3 significantly increased the yield and accumulation of secondary metabolites in basil compared with those under R:B ratios. Therefore, an R:B ratio of 7:3 combined with the applied nutrient amount of 1/2 T is considered the best combination which balances the yield and accumulation of secondary metabolites in basil plants in the present study.