THE LARGE P AND CA PREPLANTING RATES FOR TOMATO PLANTS GROWN UNDER GLASS IN DECREASED SUBSTRATE VOLUME

The influence of increasing rates of P /up to 4 g per liter of substrate/ as a triple superphosphate and ground chalk /up to 60 g per liter of substrate/ on the yield of tomato plants grown in decreased up to 4 1 per plant substrate volume was investigated.
Substrate consisted of peat and brown coal /1:1 v/v/.

Even the largest chalk rate did not decrease the tomato fruit yield when brown coal was used as an ingredient of substrate and P and micronutrients were constantly supplied.

It was possible to apply 1 g P combined with 5–15 g chalk per liter of substrate exclusively as a base dressing.

P rates larger than 1 g per liter of substrate significantly decreased tomato fruit yield, although in case of the application the rate 2 g P, harmfulness of P can be counteracted by chalk rates larger than 30 g per liter of substrate.

The critical upper P content of substrate as determined by the universal procedure at the planting time balance at about 1000. mg P per liter of substrate.

The confirmation of the Ca excess by analysis of either the substrate or the index part of tomato plants should not be expected.

Symposium on the Use of Fertilizers in Protected Vegetable Production

H. Wisniewska

https://doi.org/10.17660/ActaHortic.1984.145.6