EFFECTS OF CPPU AND GIBBERELLIC ACID ON THE CLUSTERS CHARACTERISTICS OF CENTENNIAL SEEDLESS TABLE GRAPE ABSTRACTTwo trials were conducted in a commercial vineyard, in the region of Jundiaí-SP, with the objective of studying the effects of CPPU and GA 3 on the clusters and berries characteristics of Centennial Seedless table grape. In the first experiment, it was used CPPU at 0; 5.0; 7.5; 10.0; 12.5; 15.0 and 17.5mg.L -1 . In a second trial, GA 3 was used at the doses of: 0, 5, 10, 15, 20, 25 e 30mg.L -1 . Both, CPPU and GA 3 increased the clusters weight and width; the berries weight, length and width; and the pedicel diameter. The increase in cluster length was significant only for GA 3 applications. Both growth regulators decreased the total soluble solids content. Applications of CPPU and GA 3 at 5mg.L -1 , provided increases in berries weight in 59.0 and 78.7%, respectively, and formation of untied clusters, with flexible pedicels. Higher doses led to formation of clusters too much large, excessively compact, with pedicels very thick, and, therefore, with reduced commercial value.
INDEX TERMS:Vine, Vitis vinifera L., growth regulator, cytokinin, gibberellin.
INTRODUÇÃOAs giberelinas são os reguladores de crescimento mais amplamente utilizados em nível comercial na Viticultura, visando principalmente ao aumento do tamanho e da fixação dos bagos, à descompactação dos cachos e à eliminação de sementes. Segundo Pires et al. (1986), as respostas às aplicações de ácido giberélico variam em função da cultivar e das condições de cultivo.Para a cultivar sem sementes Sultanina, El Hodairi et al. (1995) constataram aumento da massa dos cachos e comprimento dos bagos, pela aplicação de AG 3 a 50mg.L -1 , após a frutificação. Resultados semelhantes foram obtidos por Retamales et al. (1997) em uvas Sultanina , mediante duas aplicações, em pós-florescimento, de AG 3 ou mistura de giberelinas (AG 3 , AG 1 , AG 4 e AG 7 ) a 40 mg.L -1 .