This study was conducted in the Experimental Orchard, Faculty of Agriculture, Assiut University, Egypt, to investigate the influence of biofertilization on growth, leaf nutrient status and fruiting of some seedless grape cultivars during 2004, 2005 and 2006 seasons.
The experiment was arranged in a split-plot complete randomized block design with four replicates, being a vine as an experimental unit and consisted of 7 treatments.
The obtained results indicated that leaf area, pruning wood weight and leaf nutrient composition were significantly increased by using biofertilizers i.e. microbein, biogen and nitrobien. The promotion of such traits was associated with increasing the proportion of biofertilizers and decreasing the applied of mineral ones. Combined application of mineral form at 50% of recommended rate of N (RDN) plus biofertilizers gave the maximum values.
- As the interaction, all combinations of Thompson Seedless gave the highest values of such traits compared to the other studied cultivars. Whereas, all combinations of either Ruby Seedless or Flame Seedless gave similar values.
- Fertilizing the vines with RDN via mineral form combined with biofertilizers was very effective on improving berry set %, number of clusters and yield/vine compared to RDN in mineral form alone. Combined application of mineral form at 50% plus 100g of biofertilizers gave the maximum values. Ruby Seedless cv. fertilized at different treatments gave the highest number of cluster as well as heavy yield than analogous ones resulted from the combination of Flame Seedless and Thompson Seedless cultivars.
- Application of the RND via mineral combined with bio-fertilizer improving the cluster and berry attributes compared to using RND via mineral form only. The best results regarding berry quality were obtained from vines fertilized with N at RDN as 50% via mineral plus 100 g biogen/vine.
- Thompson Seedless grapes surpassed Ruby Seedless and Flame Seedless grapes in its quality from the chemical properties stand point, since it contained higher TSS% and reducing sugars %.
- All combinations significantly improved the cluster and berry attributes.
It is evident from the foregoing results that biofertilizer plus ½ recommended dose of nitrogen was sufficient to get good nutritional status, healthy and productivity of Flame seedless, Thompson seedless and Ruby seedless grapevines.
It could be recommended that 100 g of biofertilizer plus 1/2 RDN was sufficient to get a high yield with good quality and very useful in saving N fertilization cost and reducing nitrate pollution.