Evaluation of Ethiopian plant extracts,Acacia seyalandWithania somnifera, to control green mould and ensure quality maintenance of citrus (Citrus sinensisL.)

Abstract

Evaluation of Ethiopian plant extracts, Acacia seyal and Withania somnifera, to control green mould and ensure quality maintenance of citrus (Citrus sinensis L.). Abstract-Introduction. Green mould, Penicillium digitatum (Pers.: Fr.) Sacc., causes economically important postharvest disease in citrus. Materials and methods. Ethiopian plant extracts of Acacia seyal (Del. Var. Seyal) and Withania somnifera (L.) Dual were used to test the control of green mould in wound-inoculated fruit, stored for 21 d at 7°C and at > 85% RH. The chemical compositions of the two extracts were determined using high-performance chromatography. Thereafter, freshly harvested (naturally infected) fruit were subjected to different postharvest treatments and stored for 50 d to investigate the effects of the two plant extracts on fruit quality parameters. Treatments included (pre-wax + leaf extracts), (wax + leaf extracts incorporated into wax, Citrosol A ®), (leaf extract alone), (fruit washed in chlorinated water at 5.25%), (untreated fruit) and (commercially treated fruit). Results. Extracts of A. seyal and W. somnifera reduced the incidence of green mould by 56.1% and 50%, respectively, in wound-inoculated fruit. A. seyal extract contained a high concentration of gallic acid (60.3 mg•mL-1) whilst W. somnifera contained low concentrations of caffeic acid (8.7 mg•mL-1), salicylic acid (6.3 mg•mL-1) and 3,4 dihydroxy benzoic acid (3.8 mg•mL-1). Green mould was absent in naturally infected fruit subjected to (pre-wax + leaf extracts), (wax mixed with leaf extracts) and (leaf extracts) treatments. (Pre-wax + leaf extracts) and (wax mixed with leaf extract) treatments significantly reduced weight loss; retained firmness and colour; and they maintained eating qualities and a maturity index (SSC/TA) similar to commercial treatment. Conclusion. Both extracts of A. seyal and W. somnifera showed potential to be used as an alternative in combined applications with wax application under low temperature storage to replace synthetic fungicides, to ultimately control green mould and retain overall fruit quality. South Africa / Citrus sinensis / fruits / quality / disease control / moulds / Penicillium digitatum / biological control / plant extracts / Acacia seyal / Withania somnifera Évaluation d'extraits de plantes éthiopiennes, Acacia seyal et Withania somnifera, pour contrôler la moisissure verte et maintenir la qualité des agrumes (Citrus sinensis L.). Résumé-Introduction. La moisissure verte, due à Penicillium digitatum (Pers.: Fr.) Sacc., est la maladie après récolte des agrumes la plus importante économiquement. Matériel et méthodes. Les extraits de deux plantes éthiopiennes, Acacia seyal (Del. Var. Seyal) et Withania somnifera (L.) Dual, ont été utilisés pour étudier leur effet sur le développement de la moisissure verte sur fruits inoculés par blessure, puis stockés pendant 21 jours, à 7°C et HR > 85 %. La composition chimique des deux extraits a été analysée à l'aide d'un chromatographe liquide haute performance. Par ailleurs, des fruits natu...

GRAS, plant- and animal-derived compounds as alternatives to conventional fungicides for the control of postharvest diseases of fresh horticultural produce

“…(Di Venere et al, 2016), Huamuchil (Barrera-Necha et al, 2003), Acacia sp., Whitania sp. (Mekbib et al, 2009), and Parastrephia sp. (Ruíz et al, 2016), among many others (Palou et al, 2008;Sayago et al, 2012;Talibi et al, 2012).…”

A Review on the Main Phytoconstituents, Traditional Uses, Inventions, and Patent Literature of Gum Arabic Emphasizing Acacia seyal

“…In other studies, the stem bark has been reported to contain flavonoids, saponins, terpenoids, steroids, alkaloids, phenols, coumarin, and tannins [14,15]. The phenolic acids "gallic acid, salicylic acid, p-coumaric acid, caffeic acid, 3,4 dihydroxy benzoic acid, and ferulic acid" were detected in A. seyal leaves [16][17][18]. The stem bark of A. seyal (Djibouti type) was reported to contain catechin, epicatechin, lupeol, campesterol, stigmasterol, clionasterol, and oleamide [19], whereas the complex of polysaccharides and calcium, magnesium, potassium salts, protein, gallic, ellagic, and chlorogenic acids were reported as phytoconstituents of A. seyal gum [20].…”

Inhibition of Key Citrus Postharvest Fungal Strains by Plant Extracts In Vitro and In Vivo: A Review

“…The antifungal effect is better than chitosan alone, and the efficacy corresponds to the content of bergamot oil, where the composite coating effect of 3% bergamot oil has the best result [ 93 ]. Inoculation with P. digitatum Citrus was treated with two Ethiopian plant extracts ( A. seyal and W. somnifera ) [ 50 ]. It can reduce the disease incidence of green mold by 50%, which can also maintain the quality of fruit with the use of fruit wax and reduce weight loss rate.…”