Rice Husk Ash Based Growing Media Impact on Cucumber and Melon Growth and Quality

This study evaluated the effects of rice husk ash (RHA) composite substrate on plant growth, photosynthetic parameters, and fruit quality of cucumber (Yuyi Longxiang variety) and melon (Yutian Yangjiaomi variety). RHA, peat, vermiculite, and perlite were mixed in different proportions, and the conventional seedling substrate (peat: vermiculite: perlite = 1:1:1 volume ratio) was used as the control (CK). All plants were cultures in cultivation barrels filled with 10L mixed substrates. The results showed that compared with CK, RHA 40 (RHA: peat: vermiculite: Perlite = 4:4:1:1 volume ratio) could improve the ventilation of mixed substrate and improve the stem diameter, root activity, seedling index, chlorophyll content, net photosynthetic rate ( P n), stomatal conductance ( G s) and transpiration rate ( T r) of cucumber and melon plants. In addition, under RHA 40, the single fruit weight of cucumber and melon increased by 34.62% and 21.67% compared with CK. It also increased the contents of sucrose, total soluble sugar, vitamin C, and soluble protein, and enhanced the activities of sucrose synthase (SS) and sucrose phosphate synthase (SPS). In conclusion, the matrix ratio of RHA 40 (RHA: peat: vermiculite: Perlite = 4:4:1:1 volume ratio) had the best effect and could be used as the matrix formula for cucumber and melon cultivation.