G. Wallace, A. Wallace
Mar 1, 1986
Citations
0
Influential Citations
16
Citations
Journal
Journal of Plant Nutrition
Abstract
Abstract Ferric ammonium citrate is more soluble than iron sulfate, and a very few ml. is all that is needed to supply Fe to trees when injected into trunks of the trees. Ten ml. of a solution with 8% Fe contains enough Fe to increase leaf concentration in 16 kg of leaves by 50 mg kg‐1 expressed on a dry weight basis; this would be a moderately large tree. The technique used is to slant drill holes on two or more sides of a tree and at different elevations, and then add Fe with a syringe corresponding with size of tree. The tree is left to absorb the solution. Control is achieved in days for most species. A few species do not respond. Overtreatment is easy because of the high concentration of Fe. This ferric ammonium citrate method has been used on numerous trees with no injury. Regreening starts to take place within a week. A commercial product is available which has a balance of manganese with some nitrogen. The cost per very large tree for this product is about $0.25 USA. The method is rapid enough for...