Effects of Para Rubber Solution on Grapevine Physiology, Yield and Quality

Abstract

Weekly application of upto 5% aqueous of Para rubber on ‘White Malaga’ grapevines, during the rainy season, starting 20 days after pruning and last for eight weeks, showed no adverse effect on growth and development of grapevines. At 5% level, fruit set and soluble solid content were significantly higher but the pulp of grapes in this treatment became softer than those in other treatments. When the applications were done in the dry season on 'Cardinal' grapevines, no effect was found on leaf area and chlorophyll content. Transpiration was lower only during the first three days after the treatments. However, there were no differences in term of grape qualities. Para rubber application alone could not deter the development of downy mildew (Plasmopara viticola), but it could prevent the formation of sporangiophore for at leat one day.