Articles
RESPONSE OF GREENHOUSE TOMATOES TO WASTEWATER FERTIGATION IN SOILLESS CULTIVATION
In this paper, the effects of two culture solutions on the production of greenhouse tomatoes were studied in combination with two substrates of soilless systems : the inert perlite and a mixture of perlite and zeolite 1:1. The two culture solutions were : Effluents from the Wastewater Biological Treatment Plant, treated and disinfected, after chlorination and second the ordinary irrigation water, appropriately enriched with nutrients.
Fertigation with treated wastewater effluents only, without supplying any additional nutrients, improved fruit quality as a percentage of soluble solids, but increased blossom – end rot incidence.
The pH of the fruit juice and the fruit firmness were not affected.
The number of marketable fruits decreased by 18%, as well as their total weight by 34% and their mean fruit weight by 18%, in comparison with the fertigation with the ordinary nutrient solution.
The effect of the two substrates used was significant only in the case of blossom – end rot incidence, where perlite gave 2.73% affected fruits compared to 0.92% of the mixture perlite + zeolite.
Reduction in fruit yields and/or physiological disorders, such as blossom – end rot, caused by the unbalanced nutrient solution of the wastewater effluents, could be corrected merely by adjusting the concentration of nutrients.
Thus, reusing treated wastewater effluents may have positive effects on saving ordinary irrigation water and commercial fertilizers as well as preserving the environment from the nutrients that cause eutrophication.