About 91 mutants were obtained from exposing Azospirillum brasilense to different concentrations of Acriflavine mutagen and different time exposure. Out of those three new N microbial strains namely Methionineless, Threonineless and Tyrosineless were tested on Superior grapevines after their showed highest growth on artificial media. Superior grapevines were supplied with these microbial strains at 5 to 20 ml/vine and three slow release fertilizers (Methylene urea, Sulphur coated urea and urea formaldehyde) at 25 to 75% as partial replacement of the fast release N fertilizer namely ammonium nitrate during 2015 and 2016 seasons. Supplying Superior grapevines with N through 50 to 75 % inorganic N + 25 to 50% slow release N fertilizers (Methylene urea, Sulphur coated urea and urea formaldehyde) + bacteria strains (Methionineless, Threonineless and Tyrosineless) at 5 to 10 ml/vine proved to be very effective in stimulating all growth traits, leaf pigments and nutrients , berry setting %, yield and quality of the berries relative to using N as 100 % mineral N or when mineral N was added at 25%. An obvious reduction was observed on both nitrate and nitrite in the juice, with reducing percentages of mineral N from 100 to 25% as well as increasing percentages of the three release N fertilizers from 25 to 75% and the three bacterial strains from 5 to 20 ml/vine. The best bacterial strains in this respect were Methionineless, Theronineless and Tyrosineless, in ascending order. The best slow release fertilizer was methylene urea followed by sulphur coated urea. Amending Superior grapevines with N as 50% inorganic N (ammonium nitrate) + 50% slow release N fertilizer (methylene urea) + Tyrosineless at 10 ml/vine was responsible for promoting yield and fruit quality.

A laboratory experiment was conducted during 2015 and 2016 seasons to improve uptake and productivity of grapevines by producing three newly strains of solubilizing K bacteria (Histidineless, Argnineless and Phenylalanineless) by exposing the wild Streptomyces sp. with different doses of Ultraviolet irradiation from one to five minutes. These newly K strains as well as the slow release K fertilizer feldspar was used as a partial replacement of mineral K namely potassium sulphate (48% K 2 O). Supplying the vines with K as 50 to 75% mineral K plus feldspar as a slow release K fertilizer at 25 to 50% and any one of the three K bacterial strain each at 5 to 10 ml had an announced promotion on growth characteristics, pigments, N, P, K, Mg, Ca and S, berry setting (%), yield as well as physical and chemical characteristics of the berries relative to the application of K as mineral K alone. The best K strain was Histidineless followed by Phenylalanineless and strain Argnineless occupied the last position. The berries quality was remarkably enhanced due to supplying the vines with K as 50% mineral K + feldspar at 50% + Argnineless strain at 10 ml/vine. For promoting yield of superior grapevines, it is advised to supply the vines with K as 50% inorganic K plus 50% feldspar and Histidineless strain at 10 ml/vine. Supplying the vines with K as 25% mineral K + 75% feldspar + 20 ml (Argnineless strain) gave the best results with regard to berries quality.

This experiment was carry out for two successive seasons on Flame seedless grapevines (2019 & 2020) in vineyard of EL-Baramon experimental farm, Horticultural Research Institute, Mansoura, Egypt. The target of this present study was identify the optimum planting distance and number of buds which must be left per square meter to gain the best results with respect to bud behavior, characteristics of vegetative growth , yield, canopy microclimate and quality of berries. The vines were planted under three different levels of planting distances (1.5 x 3m & 2 x 3m and 2.5 x 3m) and were loaded at three different levels of buds load (8 &10 and12 buds/ m 2 ). Results showed that all studied characteristics were significantly affected with planting distance and load of buds. Increasing planting distance from (1.5m×3m) to (2.5m×3m) was accompanied with an improve in vegetative growth parameters, nutritional status, yield/vine, microclimatic data and chemical properties in berries, while decreased bud burst%, cluster and berry weight yield/ feddan. Also, increase load of buds /vine from (8 buds/ m 2 ) to (12 buds/ m 2 ) was accompanied by an increase in yield/vines and feddan, while negatively effected on bud burst%, vegetative growth parameters, microclimatic data, chemical properties in berries and total carbohydrates in cans.It could be suggested that planting Flame seedless grapevines at planting distance (2.5mx3m) or (2mx3m) with retained (8buds/m 2 ) were considered the most optimum treatment for improving vines nutritional status, vegetative growth characteristics, microclimatic data and quality of berries.