| 摘要 |
PROBLEM TO BE SOLVED: To obtain a rind-puffing preventing agent achieving sufficient effect to prevent rind-puffing of citrus fruit at a low cost by the use of a small amount of the agent in the culture of a citrus fruit by using a specific compound derived e.g. from lignite, peat, etc., as an active component. SOLUTION: A humic acid salt is used as an active component of the subject agent. The rind-puffing preventing agent for citrus fruit is irrigated from the surface of soil, sprayed on the leaf of the citrus tree or scattered on the soil in the form of granule or powder. The humic acid salt may be used in combination with other substances. The other substance is e.g. a fertilizer such as phosphoric acid. The humic acid is preferably free humic acid, its salt or nitrohumic acid. The humic acid can be produced e.g. by crushing young grass peat and adding nitric acid to effect oxidization and decomposition of the raw material. The citrus fruit is e.g. Citrus unshu, sweet summer orange, Citrus iyo, Citrus hassaku, shaddock, lemon, Chinese honey wanurco and Citrus junos. |
