| Summer-induced chlorosis is the yellowing of turf from late July into September in the northern hemisphere. It was unknown why this chlorosis occurs. Research was conducted to determine how to treat and prevent summer-induced chlorosis and also how to induce it. A preliminary study showed that chelated iron applied when symptoms are present, could alleviate the problem. Further work showed that 0.75 kg Fe/ha was the most effective rate. Attempts to reduce chlorosis by applying iron before symptoms developed were unsuccessful. Attempts to generate the symptoms in the greenhouse were unsuccessful at soil temperatures of 29.4 C, but in a field study where the soil temperature was elevated to 34.7 C with an underground heating system, symptoms developed until soil temperatures were reduced. Additional field studies were conducted to evaluate the effectiveness of several experimental iron chelates. The most effective material was BU EXP1330C. |
