Estratégias para armazenamento, germinação e desenvolvimento de porta-enxertos de abacateiro

Abstract

The objective of this study was to evaluate the impact of seed coat removal and apical cutting of avocado seeds on germination parameters, as well as to analyze the germination potential of four avocado cultivars as rootstocks (‘Breda’, ‘Fortuna’, ‘Margarida’, and ‘Quintal’) and the viability of storing budwood branches to anticipate seedling production for southeastern Brazil. The avocados were collected in early February, and all experiments were conducted under 50% shade netting. In the first experiment, seeds underwent the following treatments: seed without coat and without cut; seed without coat and with cut; seed with coat and without cut; seed with coat and with cut. In the second experiment, four avocado cultivars were used: ‘Breda’, ‘Fortuna’, ‘Margarida’, and ‘Quintal’. The seed coats of all seeds were removed. In both experiments, the seeds were sown in 2.5-liter plastic bags filled with commercial substrate composed of pine bark, and germination percentage and plant height were evaluated. In the third experiment, budwood branches of the ‘Margarida’ cultivar were subjected to three treatments: immersion in 1% sodium hypochlorite for 10 minutes, 1% Captan 500 fungicide for 10 minutes, and rinsing with distilled water. The branches were then wrapped in moistened paper towels, placed in transparent plastic bags, and stored for 0, 15, 30, 45, and 60 days in a refrigerator at an average temperature of 4oC. After this period, wedge grafting was performed, and graft take rate and scion length were evaluated. The results showed that seed coat removal increased germination rate and rootstock length. The cultivars ‘Breda’ and ‘Quintal’ stood out as the best options for rootstocks, showing higher germination percentages and growth. Furthermore, treatment with fungicide proved effective for storing propagative material for up to 30 days, maintaining the viability of budwood for grafting.