Effect of Foliar Application and Soil Addition of Licorice and Yeast Extract: B- Vegetative Growth and Fruiting of Red Globe Grafted Grapevines

Abstract

The effect of some organic substances, Licorice extract and yeast extract either singly or in mixture as foliar spraying and soil application with different concentrations 10, 15 and 20 mg/L were investigated on Red Globe grafted grape cultivars on Freedom rootstocks. Vines used in the trial were eight years trellised by Gable system, with line spacing 1.5 x 3 m and grown in a sandy soil. Canopy division has typically been accomplished by training vines to the quadrilateral cordon system. The experiment was carried out during 2015 and 2016 seasons and it consisted of 11 treatments to improve the vegetative and reproductive growth of grafted vines. Results indicated that soil application of a combination of Licorice extract and yeast 20 mg/L was superior in stimulating all growth parameters with a significant effect on yield, cluster weight, the leaf area, leaf content of pigments, berry physical characteristics, TSS%, acidity, and anthocyanin, followed by soil application of Licorice extract and yeast 15 g/L, then the foliar spaying treatments which recorded significant increments in all characters in relation to the control.