Fertilization through the addition of nano-fertilizers, added in very small quantities as a foliar spray on the vine canopy, has become one of the most effective methods in order to reduce the amount of mineral fertilizers. Therefore, this experiment was conducted on a 7 year-old "Crimson seedless" grapevines for successive seasons 2021 and 2022 to determine the optimum rates of "Nano-NPK" fertilizer to replace the "NPK" conventional fertilizer. Three concentrations of "Nano-NPK" were used as foliar application in three concentrations, 30, 200 ppm), Nano-NPK (400, 60, 400 ppm) and Nano-NPK (800,120, 800 ppm) replacing 50% of conventional fertilizer NPK compared to the soil addition of the conventional fertilizer NPK at (25, 25, 100 kg/Feddan) as a control. Our results showed that Nano-NPK fertilizer at (800, 120, 800 ppm) induced a significant increase in yield parameters, along with the chemical and physical characteristics of the vegetative growth as compared with the lower concentrations but there are no significant differences between it and the control. Thus, application of Nano-fertilizers was very effective in accelerating the clusters growth stages along with replacing the mineral fertilizers

T HE present investigation were conducted over two consecutive seasons (2020 and 2021) in a private vineyard located at El-Sadat Region, Menoufiya Governorate, Egypt on 'Early Sweet' grapevines. Two field experiments were carried out, the first to assess the impact of superabsorbent polymer (SAP) on soil hydraulic properties. The second experiment to assess the effect of SAP on the growth, quality, yield, and water use efficiency of 'Early Sweet' grapevines under different levels of irrigation water, where the soil was treated with 900, 600, 300, or 0 g SAP/vine/season, and different levels of irrigation (100%, 80%, and 60% ETc). The results of the first experiment showed an improvement in the hydraulic properties of the soil, which increased with increasing SAP doses, which can reduce the amount of irrigation water. The results of the second experiment revealed that the percentage of bud burst was increased gradually by decreasing irrigation water level and increasing SAP doses. As for bud fruitful, 80% ETc recorded the highest values using the application of 900 and 600 g SAP doses. Moreover, the application of 900g SAP under 80% ETc gave the highest values of growth parameters (shoot length, leaves number/shoot, total leaf surface area/vine, coefficient of wood ripening, chlorophyll content and leaf mineral constituents). Furthermore, the results showed that the physical and chemical characteristics of berries and clusters were increased by increasing SAP doses under 80% ETc. Concerning the yield and water use efficiency, the application of 900g SAP under 80% ETc gave the highest significant values.

Remote sensing techniques are currently used in different fields including irrigation and water management fields. One of the important fields is the calculation of water consumption (WC). Remote sensing techniques can be used to estimate actual evapotranspiration and it can also be used to estimate crop coefficients based on spectral reflectance of vegetation indices (VIs), and from a relation with normalized difference vegetation index (NDVI), which is an indicator for the absorption and the reflection ratios by the green plant. The current study used remote sensing data to calculate WC for El-Bostan irrigation district. Crop coefficient values were calculated from NDVI and reference evapotranspiration values were calculated using CROPWAT program. The obtained results were verified by comparing them with field measurements. There was a strong linear correlation between the measured and calculated values with r2 of 0.90, while the root-mean-square error (RMSE) was 0.68. The results were also verified by comparing irrigation efficiencies obtained from remote sensing and from field measurements. The results were very close to each other. The study illustrated the importance and the reliability of using remote sensing techniques in calculating WC values, and which could improve water management and water use efficiency.

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