Tomato, being a climacteric crop, has a relatively short postharvest life due to several factors such as postharvest diseases, accelerated ripening, and senescence that trigger losses in quantity and quality. Chemicals are widely used to control postharvest disease. Inaptly, it leads to detrimental effects on human health, environment and it is leads to increased disease resistance. Chitosan and vanillin could be an alternative to disease control, maintain fruit quality, and prolong shelf life. The aim of this research was to evaluate the potential of chitosan and vanillin coating on the tomato fruit’s physicochemical quality during storage at 26 ± 2 °C/60 ± 5% relative humidity. Chitosan and vanillin in aqueous solutions i.e., 0.5% chitosan + 10 mM vanillin, 1% chitosan + 10 mM vanillin, 1.5% chitosan + 10 mM vanillin, 0.5% chitosan + 15 mM vanillin, 1% chitosan + 15 mM vanillin, and 1.5% chitosan + 15 mM vanillin, respectively, were used as edible coating. The analysis was evaluated at 5-day intervals. The results revealed that 1.5% chitosan + 15 mM vanillin significantly reduced disease incidence and disease severity by 74.16% and 79%, respectively, as well delaying weight loss up to 90% and reducing changes in firmness, soluble solids concentration, and color score. These coatings also reduced the rate of respiration and the rate of ethylene production in comparison to the control and fruit treated with 0.5% chitosan + 10 mM vanillin. Furthermore, ascorbic acid content and the antioxidant properties of tomato were retained while shelf life was prolonged to 25 days without any negative effects on fruit postharvest quality.

Gray mold disease caused by Botrytis cinerea is a damaging postharvest disease in tomato plants, and it is known to be a limiting factor in tomato production. This study aimed to evaluate antifungal activities of Vernonia amygdalina leaf extracts against B. cinerea and to screen the phytochemical compound in the crude extract that had the highest antifungal activity. In this study, crude extracts of hexane, dichloromethane, methanol, and water extracts with concentration levels at 100, 200, 300, 400, and 500 mg/mL were shown to significantly affect the inhibition of B. cinerea. Among the crude extracts, dichloromethane extract was shown to be the most potent in terms of antifungal activities. The SEM observation proved that the treatment altered the fungal morphology, which leads to fungal growth inhibition. For the in vivo bioassay, the fruits treated with dichloromethane extract at 400 and 500 mg/mL showed the lowest disease incidence with mild severity of infection. There were 23 chemical compounds identified in V. amygdalina dichloromethane extract using GCMS analysis. The top five major compounds were dominated by squalene (16.92%), phytol (15.05%), triacontane (11.31%), heptacosane (7.14%), and neophytadiene (6.28%). Some of these significant compounds possess high antifungal activities. This study proved that V. amygdalina from dichloromethane extract could be useful for inhibiting gray mold disease on tomato fruit and has potential as a natural antifungal agent.

Tomato Lycopersicon esculentum Mill. is one of the most cultivated and widely consumed vegetables in the world. However, it is very susceptible to the infection initiated by Fusariumoxysporum fruit rot, which shortens post-harvest life and thus reduces market value. This disease can be regulated appropriately by the application of synthetic fungicides. However, chemical fungicides constitute a serious health risk, and have harmful environment effects and increase disease resistance, even when microbes are dead. Hence, to overcome this problem, chitosan and vanillin, which have antimicrobial bioactive properties against the growth of microorganisms, could be an alternative to disease control, while maintaining fruit quality and prolonging shelf life. The aim of this research was to evaluate the antimicrobial activity of chitosan and vanillin towards the inoculate pathogen and to investigate the effect of chitosan and vanillin coating in vivo on Fusarium oxysporum fruit rot and defense-related enzymes (PAL, PPO and POD). Chitosan and vanillin in aqueous solutions, i.e., 0.5% chitosan + 10 mM vanillin, 1% chitosan + 10 mM vanillin, 1.5% chitosan + 10 mM vanillin, 0.5% chitosan + 15 mM vanillin, 1% chitosan + 15 mM vanillin and 1.5% chitosan + 15 mM vanillin, were used as edible coatings on tomatoes stored at 26 ± 2 °C and 60 ± 5 relative humidity. The result revealed 1.5% chitosan + 15 mM vanillin was able to control disease incidence by 70.84% and severity by 70%. These combinations of coatings were also able to retain phenylalanine ammonia-lyase (PAL), peroxidase activity (POD), and polyphenol oxidase (PPO) enzyme activities as well as prolong shelf life of tomatoes up to 15 days.

Colletotrichum gloeosporioides causes anthracnose disease in papaya fruit resulting in tremendous economic loss due to its latent infection. This study aimed to evaluate the biocontrol activity of antagonistic yeasts against C. gloeosporioides in papaya and determine the possible mechanism involved. One hundred and ten yeast strains were isolated from different parts of the papaya plant. Among them, only five strains, namely F001, F006, L003, FL013 and LP010, showed more than 55% radial growth inhibition of C. gloeosporioides. These five potent yeast strains were further evaluated in vitro and in vivo. The results indicated that strain F001 had the strongest biocontrol activity based on spore germination and fungal growth inhibition. In vivo, the strain F001 caused 66.7% and 25% reductions in disease incidence and severity, respectively. Based on molecular identification, the strain F001 was confirmed as Trichosporon asahii. Despite there was no significant induction of defense enzyme activities found on the treated fruits, SEM observation showed direct attachment of T. asahii with the fungal hyphae and interfere in their establishment to the fruit surface. Based on these findings, the antagonistic yeast T. asahii strain F001 may be used as a potential natural biological control agent against anthracnose disease in papaya fruit.

Postharvest fruits including tomatoes are commonly infected by gray mold disease resulting in significant economic losses in the fruit industry. Therefore, this study aimed to develop botanical fungicide derived from Vernonia amygdalina leaf extract to control gray mold on tomato. The emulsion formulation containing surfactant, oil carrier and water was optimized at different non-ionic alkyl polyglucoside surfactants through eleven combinations of oil to surfactant ratio (0:10, 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1 and 10:0 w/w). From eight selected formulations, two formulations, F5 and F7 showed stable in storage, remarkable thermodynamic stability, smaller particle size (66.44 and 139.63 nm), highly stable in zeta potential (−32.70 and −31.70 mV), low in polydispersity index (0.41 and 0.40 PdI), low in viscosity (4.20 and 4.37 cP) and low in surface tension (27.62 and 26.41 mN/m) as compared to other formulations. In situ antifungal activity on tomato fruits showed F5 formulation had a fungicidal activity against B. cinerea with zero disease incidence and severity, whereas F7 formulation reduced 62.5% disease incidence compared to a positive control with scale 1. Based on these findings, F5 formulation exhibited pronounced antifungal activity and may contribute to the development of new and safe antifungal product against gray mold on tomato.

Botrytis cinerea, commonly known as gray mold, is a pervasive fungal pathogen that affects a wide range of plant species, leading to significant agricultural losses. The identification of Botrytis cinerea in Malaysia is crucial for protecting the agricultural sector, minimizing economic losses, ensuring food security, maintaining export quality, addressing environmental concerns, and advancing scientific research. In the present research, tomato fruits collected from Cameron Highlands, Pahang, Malaysia showed gray mold disease symptoms of B. cinerea. The fungal isolates were examined morphologically for colony colour, growth rate, conidiophores, conidia shape, and sclerotia on PDA and V8 agar. According to the results, conidiophores appeared in grape shape and length was range of 21.26-32.52 μm, ovoid conidial dimensions were in the range of 10.03-16.08 × 7.37-11.15 μm and sclerotia size was range 1.91-4.50 × 1.70-4.00 mm. All isolates were attributed to the morphospecies Botrytis cinerea on account of these characteristics. The resulting sequences deposited in GenBank were accessions MT012053 to MT012062, respectively. A BLAST analysis of the resulting 550-bp nucleotide sequences showed 99-100% identity closest matched to B. cinerea. The pathogenicity experiments showed P6 isolates of B. cinerea were highly pathogenic and caused gray mold development on tomato fruits that led to severe symptoms in five days. Meanwhile, the least pathogenic isolate was P9. In terms of temperature, B. cinerea grew faster on PDA at 20ºC, slower grew below 20ºC and did not grow at 25ºC. Identification and characterization of B. cinerea on tomato could potentially provide information to assist disease management strategies for B. cinerea.