Citation: Mosa, W.F.A.; Sas-Paszt, L.; Gluszek, S.; Górnik, K.; Anjum, M.A.; Saleh, A.A.; Abada, H.S.; Awad, R.M. Effect of Some Biostimulants on the Vegetative Growth, Yield, Fruit Quality Attributes and Nutritional Status of Apple. Horticulturae 2023, 9, 32. https://doi.org/10.3390/ horticulturae9010032 Academic Editors: Kiril Bahcevandziev, Leonel Pereira and Alan T. Critchley Received: 2 December 2022 Revised: 20 December 2022 Accepted: 23 December 2022 Published: 28 December 2022 Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). horticulturae Article Effect of Some Biostimulants on the Vegetative Growth, Yield, Fruit Quality Attributes and Nutritional Status of Apple Walid F. A. Mosa 1, * , Lidia Sas-Paszt 2 , Slawomir Gluszek 2 , Krzysztof Górnik 2 , Muhammad Akbar Anjum 3 , Abaidalah A. Saleh 4 , Hesham S. Abada 5 and Rehab M. Awad 1 1 Plant Production Department (Horticulture-Pomology), Faculty of Agriculture, Saba Basha, Alexandria University, Alexandria 21531, Egypt 2 The National Institute of Horticultural Research, Konstytucji 3 Maja 1/3, 96-100 Skierniewice, Poland 3 Department of Horticulture, Bahauddin Zakariya University, Multan 60800, Pakistan 4 Department of Horticulture, Faculty Agriculture, Omar Al-Mukhtar University, Al-Bayda 00218-84, Libya 5 Plant Production Department, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City 21934, Egypt * Correspondence: walidmosa@alexu.edu.eg Abstract: Although the application of chemical fertilizers to crops promotes plant growth and yield, their continuous use affects soil heath and creates environmental pollution. On the other hand, plant biostimulants improve nutrients absorption, plant growth, yield and produce quality and are environment-friendly. Therefore, an experiment was conducted during 2021-22 to evaluate the effect of some biostimulants on the performance of the apple cv. Anna, planted in a sandy loam soil at Marsa Matruh governorate, Egypt. Ninety trees were randomly selected and sprayed with 4 or 6% moringa leaf extract (MLE), 0.3 or 0.4% seaweed extract (SWE), 0.1% or 0.2% Fulvic acid (FA), 4% MLE + 0.3% SWE + 0.1% FA (combination 1), or 6% MLE + 0.4% SWE + 0.2% FA (combination 2) before flowering, during full bloom and one month later and compared with a control (untreated trees). The results demonstrated that spraying MLE, SWE or FA or their combinations positively improved the vegetative growth, fruit set %, fruit yield and fruit physical and chemical characteristics as well as leaf nutritional status. The positive effect of MLE, SWE and FA was increased in parallel to an increase in the used concentration of each one of them. The highest increments in the measured parameters were accompanied by the application of combination 2 over the other treatments. Keywords: Malus domestica; fulvic acid; moringa leaf extract; seaweed extract 1. Introduction The apple (Malus domestica L.) cv. Anna is widely grown in Egypt. It contains total soluble solids (TSS)  12%, total sugars  9.5%, acidity  0.8%, dietary fibers  2.3 g and protein  0.3 g. In Egypt, the apple is grown on an area of 27,417 hectares, with an annual production of 697,936 tons; the total cultivated area of apples worldwide is 4,622,366 hectares and the worldwide total annual production is 86,442,716 tons [1]. Although the usage of mineral fertilization promotes plant growth and fruiting, it has been documented that the excessive and extensive usage of chemical fertilizers reduces soil quality by reducing its organic matter content and increasing soil pollution [2,3]. Moreover, it also leads to an increase in environmental and underground water pollution, and an increase in greenhouse gases released into the atmosphere, which are not only harmful to humans but also reduce crop yield and food safety [4–7], resulting in soil degradation and compaction, which consequently leads to root growth limitation, poor aeration and drainage [8] and a decrease in the soil’s biological activities and nutrient absorption [9]. Plant biostimulants are defined as substances that can be applied to plants to enhance nutrient availability, absorption and efficiency, growth, yield and produce quality charac- Horticulturae 2023, 9, 32. https://doi.org/10.3390/horticulturae9010032 https://www.mdpi.com/journal/horticulturae