Some effects of ZincEDTA and ManganeseEDTA on nemaguard peach seedlings grown in a glasshouse

Abstract

Nemaguard peach seedlings were grown in solution (3700 ml) and in soil (1100 g) for about 2 months in a glasshouse under various levels of zincEDTA and manganeseEDTA. The objectives were to determine levels of zinc and manganese which may be toxic to peach seedlings, to determine if cutting of roots or drying of soil were factors in metal chelate toxicity and to determine if zincEDTA and manganeseEDTA could be additive when applied together in terms of phytotoxicity. The results indicated that the peach seedlings were very resistant to uptake of zinc from zinc EDTA but that manganese was more available from manganese EDTA. A very high level of zinc can be maintained in solution culture or in soil without excessive zinc uptake. Both metals added together seemed to have a syner‐gistic effect. Levels of zinc in leaves resulting in phytotoxicity may be as low as 100 mg/Kg dry weight although interactions may influence this value. The applied chelates seemed to influence iron and sometimes copper uptake.