Furthermore, Chonthicha and Thanpisit (2005) found that growth in the stem length and diameter of French marigolds was not significant after three weeks of cultivation using fish bioextract and complete nutrient solution in a soilfree culture. In the initial phase of French marigold growth, it was found that the available forms of nutrients for growth enhancement could be supported using animal bio-extracts. Soybean bioextract was the most acidic of all of bio-extracts (Table 1), but was the most suitable bio-extract for growth enhancement in the study. Chinese kale is tolerant to acidic conditions of pH 5.5–6.8 (Maynard and Hocmuth, 2007), so the acidity of 1% of soybean bio-extract may not cause any effect on Chinese kale growth, because it was diluted with neutral filtered water. However, it appeared that the amount of essential nutrients in the best diluted soybean bio-extract was not enough for Chinese kale growth enhancement. The growth rate of Chinese kale in the initial stage (7- 14 d cultivation) was lower than T1 (complete nutrient solution). All Chinese kale growth rates increased slowly and showed significant (P