Using Some Nutrients and Essential Oils for Improving ‘Crimson Seedless’ Grape Color

Crimson Seedless exhibits inadequate red color development, causing economic losses due to lower product quality. this study was conducted to evaluate efficacy of Essential oil Rosemary oil and Camphor oil with two concentrations (100 and 200 mg/L), plant growth regulators such as Abscisic (ABA) and boric acids (BA) with concentrations (100 mg/L and 200 mg/L) and ethephon (200 gm/ L) during in coloring period to increases the anthocyanin content of the skin, improving the color of the berry. In current study, a randomized block design. Clusters were sprayed twice. The first one in version stage, the second application was performed for all treatments, 15 days after the first application. The plant growth regulators of Abscisic acid 1% or Boric acid 1% and the essential oils of Camphor oil 2% were the most effective in grape coloring development and lower costs. The values were recorded using a spectrophotometer at 520 nm, and the results were expressed as milligrams of total anthocyanin sasmalvidin-3-glucoside per gram of berry skin (mg.g−1). The evaluation of the total polyphenol concentration in the pulp and skin of berries was based on the Folin Ciocauteau method (Bucic-Kojic et al ., 2007; Borges et al., 2013). The samples were macerated and 5g of this sample was homogenized with 50 mL of 50% ethanol in a blender for 2 min and centrifuged at 3500rpm for 5min. A 0.2mL aliquot of the extract was mixed with 1.8 mL distilled water and 10 mL of 10-fold diluted Folin-Ciocalteau reagent. In addition, after 30 s to 8 min, 8 mL of 7.5% Na2CO3 solution was added. All test tubes containing the mixture were shaken for10 s on the vortex and kept in the darkness for 2h. Further, the absorbance of each sample was measured after 15min using a spectrophotometer at 765nm against a blank sample. Total polyphenols was determined from the calibration curve obtained with gallic acid; readings were expressed as mg.100g−1 of berries (gallic acid equivalents). On harvest day also clusters were packed in carton boxes (2 kg grapes each)