RELATION BETWEEN PLANT YIELD AND FRUIT QUALITY CHARACTERISTICS OF TOMATO

The main objective of breeding programs is to obtain tomato varieties capable of expressing their yield potential under the most diverse conditions. However, little emphasis has been employed on the quality of the fruits produced. Thus, the objective of this work was to evaluate tomato fruit quality with regarding TSS: TA ratio, sugar reducing content, acidity, pH, total soluble solids and contents of carotenoids, ascorbic acid and potassium as a function of plant yield increase. Two experiments were carried out at the Olericulture Sector, Department of Plant Sciences, Universidade Federal de Vicosa, Vicosa, MG, from January to May 2002. A randomized block design was used, with six replicates, and three genotypes: cultivar Santa Clara, hybrid Carmem and an accession BGH-320 from the Vegetable Germplasm Bank of the UFV. The experiment was carried out in a non-heated greenhouse covered with a plastic film and in the field conditions. The increase of plant productivity reduced the fruit quality, except for TSS: TA ratio of Santa Clara and TSS of the Carmem fruits growth in the field, that had increased with the increase of plant productivity. The sugar reducing content of genotype BGH-320 growth in the non-heated greenhouse and acidity of the Santa Clara's fruits growth in the field were reduced with increase of plant productivity. TSS: TA ratio of the Carmem's fruits growth in non-heated greenhouse and potassium content of BGH-320's fruits growth in non-heated greenhouse presented quadratic behavior with increase of plant productivity.