Efeito de ácido abscísico no controle de podridão apical e na qualidade do tomate

Abstract

Phytohormones control and regulate plant growth and development. Abscisic acid (ABA) is one of the phytohormones that are involved in various stages of plant life cycle from seed to maturity. ABA is produced in the roots when the plants are under water stress and is released to the aerial parts where it acts reducing the transpiration by closing the stomata, and thereby reducing water loss. In addition the stomata closure, it promotes Ca partition into the distal end of the fruits, which is in rapid cell division, and reduces the incidence of blossom end rot (BER). Under water stress conditions, the increase of abscisic acid can stimulate the production of ethylene, which may affect the fruit quality. Therefore, the objective of the first study was to analyze the role of ABA in increasing the Ca uptake in fruit tissue as a possible mechanism of blossom-end rot incidence inhibition in water stressed tomato plants. Foliar application of ABA increased Ca partitioning to the distal end of the fruits 30 days after the beginning of flowering. ABA reduced the incidence of BER by 86% when compared with non-ABA treated plants. Thus the foliar application of ABA can significantly reduce the incidence of BER. The objective of the second experiment was to determine the effect of three methods of application of exogenous ABA on tomato fruit quality parameters. All treatments were weekly applied to the plants from anthesis to harvest maturity. ABA improved the fruit quality parameters. The method of application may have effect on fruit quality. According to the results, foliar and root ABA application can improve fruit quality.