Citation: Moldovan, C.; Zagrai, I.; Guzu, G.M.; Jakab-Ilyefalvi, Z.; Zagrai, L.A.; Mang, S.M.; Maxim, A. Alternative Ecological Products for Aphid Control on Plum. Plants 2023, 12, 3316. https://doi.org/10.3390/ plants12183316 Academic Editor: Fajun Chen Received: 17 July 2023 Revised: 6 September 2023 Accepted: 15 September 2023 Published: 20 September 2023 Copyright: © 2023 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/). plants Article Alternative Ecological Products for Aphid Control on Plum Claudiu Moldovan 1 , Ioan Zagrai 2 , Georgeta Maria Guzu 2,3 , Zsolt Jakab-Ilyefalvi 2 , Luminita Antonela Zagrai 2 , Stefania Mirela Mang 4 and Aurel Maxim 1, * 1 Department of Engineering and Environmental Protection, Faculty of Agriculture, University of Agricultural Sciences and Veterinary Medicine, No. 3-5, Calea Manas , tur Street, 400372 Cluj-Napoca, Romania; claudiu.moldovan@usamvcluj.ro 2 Fruit Research & Development Station Bistrit , a, 3 Drumul Dumitrei Nou, 420127 Bistrit , a, Romania; ioan.zagrai@scdp-bistrita.ro (I.Z.); georgeta-maria.bivolariu@usamvcluj.ro (G.M.G.); zsolt.jakab@scdp-bistrita.ro (Z.J.-I.); luminita.zagrai@scdp-bistrita.ro (L.A.Z.) 3 Department of Horticulture and Landscape, Faculty of Horticulture and Business in Rural Development, University of Agricultural Sciences and Veterinary Medicine, No. 3-5, Calea Manas , tur Street, 400372 Cluj-Napoca, Romania 4 School of Agricultural, Forestry, Food and Environmental Sciences (SAFE), University of Basilicata, Viale dell’Ateneo Lucano 10, 85100 Potenza, Italy; stefania.mang@unibas.it * Correspondence: aurel.maxim@usamvcluj.ro Abstract: Ecological farming is increasing worldwide, as more and more consumers prefer chemical- free fruits. As a result, ecological farming is becoming increasingly appealing to European farmers, including those in Romania. However, implementing an effective ecological phytosanitary program remains a challenge for farmers due to limited options and a lack of information about their effective- ness. Romania is a major producer of plums and ranks second in the world after China. Aphids are common pests of plum, and some species are vectors of the damaging Plum pox virus, and therefore require special attention regarding their control. Eight ecological products were tested both in the field and laboratory for a duration of three vegetative periods to determine their efficiency in aphid control. The effects of ecological products were compared with five chemical insecticides known to be effective against aphids. Observations were made 24 and 48 h after spraying. Two of the eight ecological products tested were proven to be efficient in aphid control, Ovipron Top and Prev-Am, with a mortality rate over 90%. The results indicate that these two ecological products are comparable in effectiveness to chemical insecticides and could be suitable candidates for both ecological and conventional treatment programs. Keywords: aphids; plum; ecological system; insecticides effect; pest; ecological phytosanitary product 1. Introduction Prunus domestica L., commonly known as the plum tree, is a highly popular and valued fruit-bearing species worldwide. Its fruits are packed with vitamins and antioxidants, making it recommended to consume 2–4 portions daily for a healthy diet [1,2]. According to data from FAOSTAT, China leads in global plum fruit production with 6,465,219 tons [3]. Romania also plays a significant role in plum cultivation, ranking second in the world with a production of 757,880 tons. Plums are enjoyed fresh, processed (dried plums, jams, preserves) and distilled to produce alcoholic beverages (plum brandy) [3,4]. Cultivating plums in an eco-friendly manner is a relatively new concept globally and is currently being studied to make it a viable alternative to conventional farming methods [5]. However, plum cultivation is prone to specific diseases and pests that can severely affect fruit quality and yield. Aphids are one of the most common pests affecting plum crops [6,7] and they mainly belong to the genus Aphis. They feed on the sap from leaves, causing the dwarfing of trees, premature leaf falling, and small fruits or premature fruit drop. Furthermore, the infested Plants 2023, 12, 3316. https://doi.org/10.3390/plants12183316 https://www.mdpi.com/journal/plants