SUCCESSIVE TOMATO CROPPING IN PEAT SUBSTRATES

Several workers (1,2,3,4) have already shown that peat is a suitable growing medium for plants. Peat composts for plant propagation have been developed in Ireland (5,6), and successfully used by commercial growers. In the growing-on stage the use of fertilised peat substrates has also given promising results (3,4,7). However, it is not known how many successive tomato crops can be grown in the same peat without a reduction in yield or at what stage physical breakdown of the peat or the incidence of disease become limiting factors. Sterilising the peat with steam will reduce the occurrence of disease organisms, but may possibly lead to a build-up of toxic levels of available manganese and accelerate the breakdown of structure. This experiment was designed to compare peat, sand and loam as growing substrates and to study the effects of successive cropping and sub-sterilisation with steam on the yield and quality of tomatoes.