Rustificação de mudas de craibeira (Tabebuia aurea (Manso) Benth. & Hook. F ex S. Moore) através do manejo hídrico e da adubação potássica.

Abstract

Rustification of craibeira (Tabebuia aurea (Manso) Benth. & Hook. F ex S. Moore) seedlings through water management and potassium fertilization. In an attempt to contribute to the understanding of some factors that act to improve the quality of forest seedlings of native species, the present study aimed to evaluate the growth of seedlings of Tabebuia aurea during the hardening phase as a function of potassium fertilization and water regime, and its biochemical behavior under unfavorable water conditions post-nursery. The experiment was conducted in two phases, the first of which corresponded to the period of rustication, evaluating four levels of potassium (0, 130, 195, and 260 mg L-1 K) and three irrigation frequencies (irrigated twice a day, irrigated once daily and irrigation every two days). In the second phase of the experiment, the plants were divided into two groups, where one remained with daily irrigation every two days and the other was submitted or water stress, by withholding water. The K does not have a significant effect on these parameters. During the hardening phase, irrigation twice increased the plant growth. The hardening using 260 mg L-1 K associated with irrigation every two days showed accumulation of soluble sugars and amino acids when the plants were exposed to water stress.