Variação sazonal do enraizamento de estacas de cultivares de Vitis rotundifolia

Abstract

RESUMO -Este trabalho objetivou avaliar o enraizamento de 9 cultivares de Vitis rotundifolia nas quatro épocas do ano (verão, outono, inverno e primavera). As cultivares estudadas foram as seguintes: Topsail, Magnolia, Creek, Noble, Roanoke, Magoon, Regale, Bontiful e Dixie, sendo a estaquia realizada em câmara de nebulização intermitente, com o intervalo de rega controlado de acordo com a época do ano. O delineamento utilizado foi o inteiramente casualizado, com quatro repetições, nove tratamentos e 15 estacas por parcela. Todos os experimentos foram avaliados após 75 dias, levando-se em consideração as seguintes variáveis: porcentagem de estacas com folha e porcentagem de estacas enraizadas por parcela; número de raízes; comprimento (cm) das raízes principais e massa seca das raízes por estaca (mg). Nas estacas lenhosas, retiradas no outono e no inverno, não se obteve enraizamento. Com as estacas semilenhosas, retiradas no verão e na primavera, ocorreu enraizamento em todas as cultivares, com destaque para as cultivares Magnolia e Noble na primavera, que apresentaram 61,66% e 51,66% de enraizamento, respectivamente. Nessa época, também ocorreu maior retenção foliar. A cultivar Bontiful demonstrou grande dificuldade de enraizamento. Para a propagação de cultivares de V. rotundifolia, recomenda-se a estaquia semilenhosa durante a primavera. Termos para indexação: videira, estaquia, propagação. SEASONAL VARIATION OF ROOTING ON STEM CUTTINGS OF Vitis rotundifolia CULTIVARSABSTRACT -The objective of this work was to evaluate the rooting on cuttings of nine Vitis rotundifolia cultivars during the seasons of the year (summer, autumn, winter and spring). The evaluated cultivars were: Topsail, Magnolia, Creek, Noble, Roanoke, Magoon, Regale, Bontiful e Dixie. The experiment was carried out under intermittent mist chamber, with irrigation controled according with the season of the year. The experimental design was in randomized blocks with nine treatments, each one with 4 replicates containing 15 stem cuttings. All experiments were evaluated after 75 days after planting and the following variables were determined: percentage of cuttings with leaf and percentage of rooted cutting per plot; number of roots, length (cm) of main roots and dried mass of roots per cuttings. No roots developed on lignified cutings collected from plants during fall and winter. Cuttings collected from all cultivars during the summer and spring, were succesfully rooted, being superior on Magnolia and Noble cultivars during the spring, that showed 61.66% and 51.66% of rooting rate, respectively. This season also showed great leaf retention. The lowest percentage or rooting was observed for stem cuttings of the cultivar Bontiful. The resulst finally showed that spring is the best season for rooting of V. rotundifolia stem cuttings.