Effect of foliar application of yeast and fulvic acid on growth, yield and storability of onion under Aswan conditions

During the two winter seasons of 2021/2022 and 2022/2023, a field experiment was conducted at the experimental farm of the Faculty of Agriculture and Natural Resources, Aswan University ,South Egypt, to evaluate the effects of foliar application of yeast and fulvic acid on growth, productivity, and storability of onion (cv. Giza 6 Mohassan) grown in sandy soil. Treatments were spraying with yeast (1, 2 and 3 g/L), fulvic acid (1, 2 and 3 g/L), and their combinations, in addition to a control. Foliar application of 3 g /L fulvic acid recorded the tallest plants after 75 days (75.83 cm in the first season and 75.25 cm in the second).The control treatment recorded the highest number of leaves (14.80 and 14.73 in the first and second seasons) .The highest fresh yield (16.96 and 17.10 ton/fed ) and cured yield (14.99 and 15.07 ton/fed ) were obtained with 3 g/L fulvic acid, The lowest weight loss during curing in the first season (11.74%) was obtained with 3g/L yeast +3g/L fulvic acid, While in the second season, the lowest ( 12.20%) was obtained with 3 g/L fulvic acid. After one month of storage, the lowest weight loss was achieved with 3g/L yeast +3g/L fulvic acid (13.86%) in the first season and 3 g/L fulvic acid (13.84%) in second season. After two months, the lowest was recorded with 3g/L yeast +3g/L fulvic acid and 3g/L fulvic acid (15.66%) the first season , and with 3g/L yeast +3g/L fulvic acid (16.56%) in the second season