This investigation was conducted during two successive seasons of 2006 and 2007 on Flame Seedless grapevines grown at the Experimental vineyard, Plant Pathology Department, Faculty of Agriculture, Assiut University. This experiment was planned to study the effect of Dormex at 3% after winter pruning or combined application of Dormex at 3% and 40 ppm GA3 plus 5 ppm CPPU when the berry was diameter was about 5 mm, respectively, as well as different potassium sources on growth and fruiting of Flame Seedless grapevines.
The data obtained during two studied seasons could be summarized under the following main points.
- All combination of used vinasse whether by spraying or soil application on the dormex treated vines resulted in a significant increase the leaf area, the percentage of N, P and K and pruning wood weight compared to potassium sulphate on unsprayed dormex vines.
- Using vinasse for dormex plus GA3 and CPPU treated vines gave the highest values of yield/vine, cluster weight, the cluster length and berry weight and size. On other hand, gave a pronounced decrease in compactness coefficient, hence produce loose cluster compared to potassium sulphate on unsprayed dormex vines.
- Dormex spraying improved T.S.S, reducing sugars and anthocyanin contents and decreased the total acidity compared to control. Contrarily, dormex followed by GA3 plus CPPU spraying was increased the juice titratable acidity and reduced T.S.S. So, using vinasse either as foliar spray or soil dressing improved the chemical properties of berries and overcome the adverse effects due to GA3 and CPPU using in grape production i.e., delayed the berry ripening and reduce full coloration. This advantage will eventually enable growers to produce early and heavy clusters of Flame Seedless grapes, consequently the growers obtained highly marketable yield in surrounding and overseas markets.