Thinning of ‘Esbal’ clementine with 2,4-dichlorophenoxyacetic acid. Influence on yield, fruit size and fruit quality.

• Autor(a) principal: Duarte, Amílcar
• Data de Publicação: 1996
• Outros Autores: Trindade, D. T. G., Guardiola, J. L.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/10365

Esbal clementine, which originated as a bud sport from ‘Fina’, is a high parthenocarpyc early maturing cultivar with outstanding fruit quality. The expansion of this cultivar is nevertheless impaired by the small fruit size, as up to 40% of the total yield may be unmarketable due to this reason. Extensive hand thinning and auxin applications at June drop have been tried to overcome this problem with limited success. The application of a 2,4-D spray at or shortly after bloom thins effectively the number of fruits without affecting total yield, reducing the percentage of unmarketable fruit down to 13% and increasing the mean size of the marketable fruit. This thinning effect is not related to an auxin-induced ethylene synthesis, but results from the selective enhancement of the growth of some fruits by the 2,4-D application. The 2,4-D applications had no direct effect on sugar and acid content of the fruit nor in the maturity index, but the increase in fruit size resulted in an earlier maturity. This applications resulted in a reduction in juice content, but this reduction was smaller than observed when auxins were applied at june drop.