The efficacy of 6-benzyladenine, gibberellins4+7 and prohexadione-calcium to increase fruit size in ‘Forelle’ and ‘Abate Fetel’ pear

Abstract

Fruit size is an important marketing and quality parameter and has a significant effect on the economic value of fruit. The application of synthetic cytokinins are believed to enhance fruit size by stimulating and extending the cell division stage in fruit when applied at the correct time during fruit growth. In addition, a combination of prohexadione-calcium (P-Ca) with gibberellins4+7 (GA4+7) was used successfully on Japanese pear (Pyrus pyrifolia Nakai) and ‘Bing’ sweet cherry to improve fruit size. This combination of GA4+7 and P-Ca was evaluated and combined with 6-benzyladenine (6-BA) treatments on European pear (Pyrus communis L.) cultivars Forelle and Abate Fetel to determine whether fruit size can be improved under the Mediterranean-type growing conditions in South Africa. On both ‘Forelle’ and ‘Abate Fetel’ the combination of GA4+7 and P-Ca increased fruit size but the effect was more pronounced in ‘Abate Fetel’; further addition of 6-BA did not improve fruit size in these two cultivars over two consecutive seasons.