Efficacy of foliar application of diluted acids and iron salt mixed with citric acid in recovery of chlorosis in citronella Java and lemongrass.

摘要

The efficacy of foliar spray of aqueous solution of ferrous sulfate mixed with citric acid to recover chlorosis in two essential oil-bearing aromatic grasses, citronella Java (Cymbopogon winterianus) and lemongrass (C. flexuosus), was compared with the foliar spray of diluted acids (citric and sulfuric acid). The increase in chlorophyll and orthophenanthroline-extractable active iron was significantly higher in leaves of both plant species sprayed with aqueous solution of ferrous sulfate mixed with citric acid compared to that sprayed with diluted citric or sulfuric acid alone. The number of re-greened clumps and essential oil yield of both plant species were also higher in the plants sprayed with aqueous solution of ferrous sulfate mixed with citric acid. The results suggest that the foliar application of iron through aqueous solution of ferrous sulfate mixed with citric acid was more effective and responsible for the recovery of chlorosis in citronella Java and lemongrass than H+ ion through diluted acid spray.