INFLUENCE OF PHOSPHORUS FERTILIZATION AND AVAILABILITY ON GROWING AND PRODUCTION OF SOWN TOMATOES

Y. Dumas
For processing tomato, total P2O5 uptakes are rather low : about 1 kg/ ton of fruits. However phosphorus availability and taking easiness are important for the very young plant to enhance flowering precocity; thus, in the South of France, producers bring to soils great quantities of phosphorus which becomes later insoluble in calcareous soils. Now we must try to reduce the cost of production and consequently of fertilization.

Experiments in pots and in fields have shown that in a clay soil, calcareous and very poor in phosphorus, it is possible to reduce notably phosphorus supply to a sown tomato by localizing it 5 cm under the seed or even directly on the seed : from the equivalent of 50 kg/ha brought as triple superphosphate, we observe a multiplication by almost 10 of the speed of dry matter accumulation until the first trusses, which appear then about ten days before the control. When using ammonium phosphate, the advance is smaller and, with high doses (> 150 kg P2O5/ha, localized) there is a delay with regard to the control, by reason of saltness.

There are no significant differences for yields, except for the control when it meets high temperature conditions in summer; in the opposite case its yield is equivalent but later with a less concentrated ripening.

Dumas, Y. (1988). INFLUENCE OF PHOSPHORUS FERTILIZATION AND AVAILABILITY ON GROWING AND PRODUCTION OF SOWN TOMATOES. Acta Hortic. 220, 245-252
DOI: 10.17660/ActaHortic.1988.220.33
https://doi.org/10.17660/ActaHortic.1988.220.33

Acta Horticulturae