文摘
A survey was conducted in the sugarcane ratoon crop in Guangxi Province to investigate the cause of chlorosis in ratoon canes. The soil and leaf samples from highly chlorotic ratoon clumps were collected and analyzed. The results of this study revealed that the chlorotic symptoms in the leaves of ratoon cane mainly occurred in strongly acidic soil (pH < 4.50) with low content of available Fe, Ca and Mg. Nutrient imbalance caused by low content of active Fe and high content of active Mn in the leaves was found as the major reason for chlorosis in ratoon crop of sugarcane. Spraying of aqueous solution containing nutrients such as Fe, Mg, B, Ca, K, Zn and N on the leaves of sprouting ratoon crop in affected fields could reduce the chlorosis symptoms which, at the later stages of crop growth, was found to be completely rectified. Foliar spray of Fe gave the best results followed by that of Mg and B.