Different studies have suggested that the use of vermicompost as part of the plant growth media can provide nutrients and retain moisture while promoting the development of crops. To corroborate this assumption we tested the effects of vermicompost supplementation to tomato (saladette type) under greenhouse conditions. The evaluated treatments included four mixtures (T1, T2, T3, and T4) of vermicompost and river sand, with volume ratios 0:1, 1:1, 1:2 and 1:3, respectively. Physical and chemical tests were performed in each mixture to determine nutritional elements (N, P, K, Ca, Mg, Na, Fe, Cu, Zn, Mn, organic matter, pH, texture, cationexchange capacity, electric conductivity, and apparent density) and water holding capacity. Treatment with 0:1 volume ratio (T1) was used as control, and it was fertilized with a nutrient solution [KNO3, Ca(NO3)2, Mg(NO3)2, phosphoric acid concentrate, and multi Maxiquel (Bioagro ®)]. Seeds were sown in polystyrene trays with 200 cavities, padded with peat moss; seedlings were transplanted 37 days after sowing in 20 L black plastic bags. Harvest, including up to the fifth cluster, was performed manually, when the fruits reached a pink color. The treatment effects on tomato were evaluated considering the number of fruits, number of locules, equatorial and polar diameters, pulp thickness, soluble solids, fruit weight and fruit yield. The four treatments were repeated eight times in a completely randomized design. Data were statistically analyzed by analysis of variance and means were separated by the LSD0.05 test. Five of the variables studied - number of fruits, number of locules, soluble solids, pulp thickness, and yield- showed highly significant difference (P?0.01) among treatments; the polar diameter showed significant differences (P?0.05), and both equatorial diameter and weight of fruit were not significantly different among the substrates tested. The maximum yield (50.29 t?ha-1) was obtained in treatment T2 with a water volume of 40 L?pot-1, followed by T1 (49.93 t?ha-1), applying a water volume of 95.72 L?pot-1. Derived from the results of the best treatment (T2), and under conditions described, the productivity was estimated in 30.66 kg?m-3. Since no synthetic fertilizers were used during the crop production, the results indicate that the vermicompost was able to satisfy the nutrient demand of tomato plants and reduces the volume of water required by this crop.
Key words: Earthworm, Humus, Organic manure, Solanum lycopersicum, Water holding capacity