Identification of the causes of onion (Allium cepa) post-harvest losses in Morocco

L’oignon figure parmi les principales cultures maraîchères au Maroc. Cependant, plusieurs types de pertes peuvent avoir lieu après leur récolte. Notre objectif est d’étudier la situation de cette filière en post récolte et d’identifier les causes et les contraintes rencontrées au cours de la mise en vente et de la consommation de ce produit dans la région de Khémisset (Maroc). L’enquête auprès de certains acteurs de cette filière nous a permis de déterminer les types et l’ampleur des pertes. Les dégâts observés sont causés principalement par des facteurs mécaniques et pathologiques. Nous avons identifié deux champignons phytopathogènes, Fusarium sp. et Aspergilus niger. En outre, l’étude a révélé des pertes moyennes d’environ 17% chez les grossistes, 15 % chez les commerçants et 27% chez les ménages. Mots-clés: Pertes en post-récolte, oignon, champignons phytopathogènesOnion is one of the main commodities in Morocco. However, several types of losses may occur at postharvest. Our objective is to study the situation of this post-harvest sector and to identify the causes and constraints encountered during the sale and consumption of this product in Khémisset region (Morocco). The survey of certain stakeholders allowed us to determine the types and extent of losses. The damage observed is caused mainly by mechanical and pathological factors. We identified two phytopathogenic fungi, Fusarium sp. and Aspergilus niger. In addition, we found that average losses were of about 17% among wholesalers, 15% among traders and 27% among households. Keywords: Postharvest losses, onion, phytopathogenic fung

Chemical composition, antibacterial and antioxidant activities of Moroccan

Medicinal and aromatic plants have been widely used for their potential ability to curing diseases and injury. Numerous studies were focused nowadays on the pharmacological proprieties of these plants including the antibacterial and antioxidant activities. In this context, the present study aims to determine the chemical composition of essential oils (EOs) from wild carrot (Daucus carota Linnaeus) and evaluate their and antioxidant and antibacterial activities. The essential oil was obtained by Clevenger apparatus hydro-distillation and analyzed, afterward, using Chromatography-Mass spectrometry (GC-MS). A diffusion technique on agar plates was applied to determine the EOs effect against Gram-positive bacteria, whereas the DPPH radical reduction (1,1-diphényl-2-picrylhydrazy) method was used to estimate the antioxidant activity. Findings analysis identified 57 volatile components during this experiment with a majority of α-Pinene (23,5%) and β-Asarone (16,70%). Therefore, the tested EOs revealed great inhibitory properties against the Gram-positive bacteria, and an antioxidant potential with IC50 = 73.31 ± 4.46 µg/mL

Antifungal activity of plant extracts against tomato’s fungal diseases

Fungal diseases have always been a major problem for tomato crops. Growers generally use chemical fungicides to treat this type of diseases. However, these products are toxic to the environment and the consumer, especially if the pre-harvest interval is not respected. The present study aims to find non-polluting alternatives. Five plant extracts (Peganum harmala, Ocimum basilicum, Caralluma europaea, Nerium oleander and Eucalyptus globulus) are tested for their in vitro efficiency against four pathogenic fungi: Alternaria solani, Botrytis cinerea, Botrytis cinerea taken from fruit, Phytophthora infestans and Oïdium oxysporum. The obtained results reveal that the extract of Ocimum basilicum is the most effective on the studied fungi. Indeed, at a concentration of 0.4%, it inhibited at 80% the development of Botrytis cinerea and at 81% Oïdium oxysporum at a concentration of 0.2%. Followed by Peganum harmala and Nerium oleander, which also showed an antifungal effect (Peganum harmala inhibited up to 73% of the growth of Alternaria solani at a dose of 4%). The extracts of Caralluma europaea and Eucalyptus globulus proved similar antifungal activity, which exceeded 30%. The study of the fungal/fungistatic effect revealed that all the studied extracts have a fungal effect against the treated fungi. The phytochemical screening showed that the plants extracts are rich in polyphenols especially Ocimum basilicum, Peganum harmala and Nerium oleander. This leads us to deduce that the antifungal activity may be due to this