###### Abstract  
Background: Hop cultivation requires an abundant quantity of nutrients to reach higher cone yield and quality. The aim of this work was the evaluation of different fertilization plans to obtain an improvement in product quality. Methods: Foliar analysis, anatomical analysis through the use of light microscope and SEM; physiological measurements through atLEAF, Handy PEA and spectrophotometry, were carried out to determine chlorophyll content, carotenoids and photosynthetic efficiency in two periods (t1, t2) for four experimental treatments and a Control (Treat 1, Treat 2, Treat 3, Treat 4, Untreat). Leaf texture (texture analyzer), color (colorimeter), DPPH activity (spectrophotometer), bitter acid content (HPLC-UV) and essential oil yields (steam distillation) and cone yields were measured. Results: Treat 2 showed the best performance: (i) in leaves, in terms of texture, chlorophyll content and color; (ii) in cones, with 6.98% of alpha acids, 1.78% of oil yield and 3.55 kg of fresh cones per plants. Conclusion: The fertilization plans caused alteration in micro and macro elements content in hop leaves and in the composition of hop cones. In our conditions, the best fertilization plan, in terms of cone productivity and quality, was Treat 2, highlighting the value of a customized organic foliar fertilization plan for hop cultivation. 16 June 2021 21 July 2021 23  
activities; it is necessary for the formation of vitamins and reserve substances, and it has an active role against pests and diseases [12; 13; 14]. P requirement in hop is modest, estimated in 7.5-9 kg ha\({}^{-1}\) of P\({}_{2}\)O\({}_{5}\)[2]. Another key nutrient for hop growth is potassium (K). In plants, K has a fundamental role in osmotic pressure control, turgor adjustment, control of membrane polarization and protein biosynthesis [15]. From different studies [16; 17; 18], it appears that the use of K significantly reduces the occurrence of pests and diseases. In hops, fertilization requirement of K (in K\({}_{2}\)O) varies from 80 to 138 kg ha\({}^{-1}\). Also macro-nutrients, micro-nutrients such as boron (B), calcium (Ca), magnesium (Mg), manganese (Mn), iron (Fe) and zinc (Zn) are fundamental for the healthy growth of hops. The deficiency of these nutrients determines chlorosis, and since they are involved in cone formation, plant metabolism and accumulation of secondary metabolites, they play a fundamental role in the final quality of hop production [1]. There are different methods to supply the required nutrients to plants; the traditional ways are based on manuring and chemical fertilization that, however, have environmental costs in terms of soil and groundwater leaching. Compared to this, a more environmentally friendly method of nutrient supply is foliar fertilization. In fact, spraying nutrients on leaves reduces the nutrient quantities required, determining a more efficient fertilizer management and a more efficient plant uptake, while avoiding soil leaching [19]. This method allows nutrients to be apportioned to plants in the exact moment they are required, increasing absorption speed and giving a fast plant response [19; 20]. However, it is important to determine the right quantity of fertilizers to be used, in order to avoid damage to leaves and preserve the soil and environment. Hop, as a susceptible crop with scarce resistance to fungi and pests in many varieties, usually requires the use of both pesticides and mineral fertilizers during its cultivation. The use of organic manure and foliar fertilization for hop cultivation could reduce its environmental impact, and enhance soil fertility and biodiversity, which are, on the other hand, damaged by the intensive use of mineral fertilizers and pesticides [21; 22]. With this premise, the aim of this study was the development and optimization of organic fertilization in hop cultivation, in order to obtain better yield and cone quality, but also to minimize the impact on the environment through foliar fertilization spraying.