Growing Tomato Plantlets on Various Mixtures of Peat and Sand or Peat and Perlite. Note 1

Given the considerable interest in use of substrates derived from various mixtures in the nursery sector and in light of the enormous variety of possibilities offered by this technique, in contrast with the still small number of researches dedicated to this theme, this study was set out to examine in-depth the growing of tomato plantlets on peat-based substrates. Two series of peat mixtures were produced, one with sand and the other with perlite, with a volume ratio of the other two components with respect to the peat of 1:0, 2.5:1, 1:1 and 1:2.5. Tomato seedlings were cultivated for 30 or 25 days in small perforated pots containing these mixtures. The irrigation was calculated by weighing each pot daily, measuring the water lost by evaporation-transpiration, then just past an established lower threshold value bringing the water back up to a defined upper threshold. Two water regimes were compared in the sand series and three in the perlite series.