Abstract

The correct management of organic fertilization has been shown as an extremely viable alternative in the production of vegetables, providing high yields concomitant to the reduction of synthetic fertilizers. The improvement of the production can be interpreted by the physiological behavior, favored by the organic fertilization with the supply of nutrients. Thus, an experiment was carried out to evaluate the gas exchange and Soil-Plant Analyses Development (SPAD) chlorophyll content in tomato plants according to types of organic fertilizers and biofertilizer doses. The experimental design was completely randomized with treatments distributed in factorial arrangement (3 x 5), referring to organic fertilizer types (T1: earthworm humus; T2: goat manure and T3: cattle manure) and biofertilizer concentrations (600, 800, 1000, 1200 and 1400 ml), with four replications. The gas exchange and the SPAD chlorophyll content in tomato plants depend on the type of organic fertilizer and the concentration of biofertilizer. It was possible to observe that increasing doses of biofertilizer in the substrate with low organic concentration increase the gas exchange in tomato plants, while high doses together with more concentrated organic fertilizers reduce these characteristics.

Key words: Alternative fertilizer, Lycopersicon esculentum, photosynthesis, organic fertilizer.