COMPOST TEA AS ORGANIC FERTILIZER IN THE PRODUCTION OF GREENHOUSE TOMATO (Lycopersicon esculentum Mill.)

The objective of this study was to evaluate compost tea as a source of N and other nutrients in the production of greenhouse tomato. Four fertilization treatments were evaluated in three cultivars. Fertilization types were nutrient solution in sand, compost tea in sand, diluted compost tea in sand + compost and split application of compost. Tomato cultivars were Bosky, Romina and PX01636262. The evaluation was carried out up to the eighth fruit cluster. The fertilization type and cultivar effects were significant for tomato yield, while their interaction was not significant. Plants treated with nutrient solution showed the highest yield with 21.8 kg·m-2, whereas compost-tea-treated plants yielded 17 % less; this reduction was related to a higher electrical conductivity (EC) in the substrate solution. Compost tea also reduced fruit weight by 21 % and increased soluble solids by 19 %. Bosky and PX01636262 cultivars yielded about 20 kg·m-2, whereas Romina yielded significantly less, because of lower fruit weight. Leaf N concentration at the beginning of flowering and beginning of harvest was similar in plants with nutrient solution and compost tea; since no deficiency Té de composta... symptoms were observed, compost tea supplied the N and other nutrients required, producing more than 18 kg·m-2 of extra large fruits, with more than 4 oBrix and lower fertilization cost.