One of the most important problems facing red globe grapevine is limited vegetative growth which promotes cluster sunburn. This study was conducted during two seasons of 2021 and 2022 on five‒ year-old red globe grapevine to evaluate the possible improvement of growth, sunburn, yield, fruit quality and nutrient content by applying yeast and gamma-irradiated licorice extracts. Yeast extract soil added to the vines at concentration of 0 and 4 g L-1, while licorice (Glycyrrhiza glabra) extract, whether irradiated or not was sprayed or soil added at three levels (0, 4 and 8 g L-1). The results indicated that the application of licorice extract alone was superior to yeast extract. The higher level of licorice, whether soil added or foliar, yielded the highest values compared to the lower level. Combined application of yeast and licorice extract, whether irradiated or not, gave a superior response compared to sole application. Additionally, the addition of licorice extract alone or combined with yeast extract significantly reduced the number of clusters affected by sunburn. In conclusion, gamma irradiation of licorice enhanced its positive effect on most of the measured properties of red globe grapevine, especially when yeast extract was added in combination.