Minimizing mineral-N fertilization Superior seedless grapevines by using humic and fulvic acids

Abstract

Nowadays a great attention is focused on minimizing the intensive amounts of mineral nitrogen fertilization by applying organic amending such as humic and fulvic acids which considered the main fraction of humic substances and fulvic acid could activate growth and product of plants. To achieve this aim, an experiment was conducted on 14 years old Superior seedless grapevines in 2020, 2021 and 2022. Application of mineral-N at 50 to 75% of recommended dose of nitrogen (RND) along 25% of humic acid or/and fulvic acid. The experimental vines were set up in a randomized complete design with four treatments and three replications two vines per each. The gained results could be briefing as follow: Using RDN via 50 to 75% mineral plus 25% humic acid and/or fulvic acid significantly increased, leaf area, pruning wood weight, and leaf total chlorophyll as well as leaf nutrient composition resembled to use RDN via non-organic-N fertilizer alone. Combination fertilization handling significantly increase the yield and improved the cluster and berry characteristics compared to use RDN through mineral source alone. Therefore, applying humic or fulvic acids improved the productivity and quality of Superior seedless grape, and proved that it could be used as alternative organic N fertilization in the future. It could be consummated that fertilized vines with 75% of nitrogen needed plus 25% humic acid or/and 25% fulvic acid improved the vegetative growth, status of nutritional, yield and cluster attributes and berry traits of Superior seedless grape-vines under this experiment circumstances