Post-emergence treatment of iron-related rice-seedling chlorosis

A number of nutritional problems have been reported for production of rice (Oryza sativa L.) on organic soils (Histosols). One of these, termed rice-seedling chlorosis, occurs when rice is drill-seeded into certain drained Histosols, and results in chlorotic, weakened seedlings that often die before or during imposition of the permanent flood. The condition can be predicted on the basis of soil testing and can be prevented by applying water-soluble Fe with the seed at planting. Greenhouse and field studies were conducted to determine the degree to which this problem can be corrected by the use of post-emergence foliarly applied Fe when the condition is not attended to at planting. It was determined that foliar application of Fe improved seedling growth, reduced seedling mortality, and increased rice grain production relative to no treatment. Nevertheless, prediction by the use of soil testing and prevention by application of Fe at seeding appears to be a more effective method for correcting seedling chlorosis than post-emergence foliar application of Fe.Florida Agricultural Experiment Station, Journal Series No. R-01230.