Utilization of Plant Growth Regulators for Improving the Recovery Rate of Fertilizers in Rice.:Effect of L-B-Phenyllactic Acid on Growth of Rice Seedlings.

the total root area was calculated according to the method proposed by Kimura (2001) after two weeks seeding. The plant age and plant height of rice seedlings were markedly enhanced by LBP treatment than those of control. The seminal root length of seedlings was also significantly (P<0.05) increased by 26% compared with that of control. In contrast, the root number per seedling was not affected by LBP treatments. Correlation between the total area of root, and the number of root or the seminal root length were not observed. It should be noted that LBP significantly (P<0.05) increased the total area of root of seedlings by increasing those of the thinner lateral root (less than 0.757 mm in diameter), not of the thicker one. In conclusion, the high recovery rate of fertilizer in co-situs application using a CRF (controlled-released fertilizer) is possible by using LBP.