Reidratação de mudas de araçazeiro amarelo após estresse hídrico

Abstract

The native fruit trees of the South of Brazil have a fundamental role for the people cultural development from region, since they can generate profit, with the implantation of orchards and also diversify the consumption of healthier foods, in which it can use the yellow araça tree. This fruit is still little explored, which make them neglected and unknown by the population due to the lack of information on the management of the species in the field. As water is one of the essential elements in the maintenance and growth of any vegetable, obtaining a water regime, indicating how long the araça tree can remain without irrigation and if later can be rehydrated, resuming its normal development, becomes essential for its use in orchards. The purpose of this work was to evaluate the growth and survival of the yellow araca tree submitted to different periods of water restriction. The work was carried out at Universidade Tecnológica Federal do Paraná. The yellow araçá seedlings were used, with approximately three years old. The experimental design was completely random, with 11 treatments, consisting of four replicates, with 10 plants per experimental unit. The yellow araça seedlings were irrigated daily, manually, with 500 mL of water per seedling in different periods, in which were 21, 19, 17, 15, 13, 11, 9, 7, 5, 3 and 1 day consecutive, that is, in the treatment one day, the irrigation was done on the first day, leaving the plant without access to water for 20 days. After each treatment, all the seedlings were submitted to daily irrigation for 90 days. After this period, the total number of leaves were analyzed, and of these were still dry or necrotic and sound, height, diameter in the neck region, number of primary shoots and length, as well as contents of chlorophyll A, B and total, dry mass of shoot and root. Data were submitted to the Liliefors Normality test, later transformed to analysis of variance and regression. All analyzes were performed by the Statistical Analysis System (SANEST®). Variables such as number of dry leaves, leaf leaves and total leaf, contents of chlorophyll A, chlorophyll B and total chlorophyll, root dry matter mass and number of shoots had a significant effect. However, the other variables did not have a significant effect of the treatments. It can be noticed that the growth variables were not affected by the water deficit and only affected those corresponding to the physiology of stress, such as leaves and roots. Yellow araçá seedlings survived the period of water stress, but negatively interfered with the availability and chlorophyll composition of the leaves, as well as the root system.