Journal of Horticultural Science & Ornamental Plants 13 (3): 272-281, 2021 ISSN 2079-2158 © IDOSI Publications, 2021 DOI: 10.5829/idosi.jhsop.2021.272.281 Corresponding Author: Sameh M.M. El-Sawy, Vegetable Research Dept., Agricultural and Biological Research Division, National Research Centre (NRC), Giza, Egypt. 272 Improving Yield, Physical and Chemical Qualities of Sweet Fennel Bulbs by Spraying of Potassium Humate S.M. El-Sawy, A.M. El-Bassiony, Z.F. Fawzy and Shaymaa I. Shedeed 1 1 1 2 Vegetable Research Dept., Agricultural and Biological Research Division, 1 National Research Centre (NRC), 33 El-Buhouth St., 12622 Dokki, Giza, Egypt Plant Nutrition Dept., Agricultural and Biological Research Division, 2 National Research Centre (NRC), 33 El-Buhouth St., 12622 Dokki, Giza, Egypt Abstract: Under the limited water resources and arid climate in Egypt, using the proper agricultural methods and techniques for increasing the vertical expansion through increasing the production per area unit is needed. Non-traditional vegetable crops are promising crops for local consumptions and exportation, increasing their production will increase the income. For this issue two field experiments were conducted during 2017/2018 and 2018/2019 seasons using two sweet fennel cultivars (Dolce and Zefa fino) to study the effect of foliar application of potassium humate concentrations at 0, 2, 3, 4 and 5 cm L on vegetative growth parameters, 1 chemical composition and yield and quality under sandy soil condition. The results revealed that Dolcy cv. showed superiority on Zefa fino cv., where the highest significant values for vegetative growth, leaf and bulb chemical compositions, yield and quality characteristics were obtained than the other cultivar. The results also illustrated that increasing the concentration of potassium humate application enhanced the vegetative growth, leaf and bulb chemical compositions, yield and quality of sweet fennel plants. Moreover, the maximum significant values were reported with 4 and 5 cm L K-humate treatments as a foliar spraying. It could be 1 recommended that, for producing sweet fennel in sandy soil in Egypt, Dolce cv. is the best choice with foliar application of K-humate at 4 and 5 cm L two times (6 and 8 weeks from the planting date) for increasing the 1 yield and quality as well as the essential oil content. Key words: Sweet fennel Cultivars Potassium humate Essential oil Yield and quality INTRODUCTION Sweet fennel (Foeniculum vulgare Mill.; Fam. Egypt is located in arid regions which facing many vegetable crops which cultivated in Egypt for export and problems; high temperatures, salinity and drought local consumptions. In addition, it is considered as the stresses. As well as, in the new reclaimed sandy soil most important economic medicinal and aromatic plant organic matter status comes down below 1% and adding grown in Egypt [3]. Sweet fennel plants are used fresh the organic fertilizers only to increase the soil fertility has for salads and cooking. Additionally, fennel oil is used not proved to be very successful under high temperature as an aromatic carminative, stimulant and condiment. conditions [1]. For improving the plant growth and Sweet fennel is an essential medicinal and aromatic plant increasing the production it should to supply plants by which their parts (stem bases, leaves and seeds) have foliar fertilizers beside the normal way which plants essential oil and are used as flavoring agents in food absorb the soil fertilizers by roots especially under non products such as bread, pickles, pastries and cheese suitable conditions in the arid lands. In the foliar spraying [4].Fennel is one of the real basic oil plants that have been plants quickly absorb the nutrients by leaves and developed and the concentration of the essential oil in the transport to the different parts of the plant [2]. ripe fruits is between 3-6% [5]. There are many cultivars of Apiaceae (Umbellifera)) is one of the non-traditional