An applied study to improve Le-Conte pear productivity and quality using potassium humate with hydrogen peroxide or irradiated licorice extract

Pears are popular among fruits around the world, but their production faces many challenges, the most important of which is fire blight, which affects productivity and tree quality. Foliar application of organic fertilizers and natural substances could maintain productivity and fruit quality. This study was conducted on fifteen-year-old Le-Conte pear trees to evaluate the feasibility of foliar application of potassium humate, hydrogen peroxide, and gamma-irradiated licorice extract to improve yield, quality, and control fire blight. Data revealed that all individual foliar spray treatments significantly improved the fruit's physical and chemical characteristics and yield, while the percentage of fire blight infected fruits significantly decreased compared to the control (no spray). Combined sprays improved the above-mentioned parameters more than sole application. Gamma-irradiated licorice gave a more superior effect in most cases, while hydrogen peroxide was more effective in combating the fire blight infection. Combination of high levels of potassium and licorice gave the highest increment in TSS (28.1%), vitamin C (66%), and total sugars (37.5%) with maximum reduction of acidity (64.8%) while high levels of potassium and hydrogen peroxide gave the highest yield (85.3%) and maximum reduction of fire-blighted fruits (83.7%). In conclusion, Le-Conte pear trees productivity and quality can be increased, while fire blight affected fruits can be decreased, by using a foliar spray of potassium humate with hydrogen peroxide or irradiated licorice extract.