The effect of some media components on the micronutrient composition of some container-grown plants : a thesis presented in partial fulfilment of the requirements for the degree of Master of Horticultural Science at Massey University

Abstract

Plants were grown in a range of soilless growing media made from peat, perlite and pumice. Plant samples and media extracts were analysed by atomic absorption spectrophotometry. All media components used proved to be sufficiently reactive with respect to micronutrients to modify nutrient levels in plant foliage. This is supported by differences in micronutrient extractability and sorption by media components. The use of fritted trace elements did not prevent the appearance of Fe chlorosis, but did increase the foliar level of some micronutrients. The results show some nutritional differences between peats from different sources. Differences in mineral uptake associated with perlite and pumice were also observed. These differences may explain why iron chlorosis may be induced in plants grown in perlite based substrates and not in pumice based substrates.