Evaluation of essential oils for preventive or curative management of melon gummy stem blight and plant toxicity

Abstract

Melon cultivation is frequently heavily reliant on synthetic fungicides, including products used to control gummy stem blight caused by Stagonosporopsis cucurbitacearum. The essential oils used in controlling plant pathogens may offer an alternative to chemical pesticides. This study evaluated the effectiveness of essential oils to control the gummy stem blight in melon plants. In vitro tests were carried out using essential oils obtained from ripe noni fruit (Morinda citrifolia) and dehydrated leaves of the following plants: lemon grass (Cymbopogon citratus), citronella grass (Cymbopogon nardus), basil (Ocimum basilicum) and Mexican tea (Chenopodium ambrosioides) at different concentrations. A synthetic fungicide was used as control treatment. Results showed that the essential oils from noni and lemongrass had the highest effect on mycelial growth inhibition in S. cucurbitacearum. When applied on melon plants as a preventive measure, the essential oils from noni and lemongrass controlled gummy stem blight at the following concentrations: 0.03, 0.05, 0.1 and 0.3%. These results highlight the potential of essential oils to manage melon fungal diseases, which may result in reduction of pesticide application.

Evaluation of Seven Essential Oils as Seed Treatments against Seedborne Fungal Pathogens of Cucurbita maxima

“…Naveenkumar et al [54] reported that for Oryza sativa (rice) seedlings, a C. citratus essential oil increased the seed germination, shoot length, root length, and vigor. Also, a C. citratus essential oil was shown to reduce the severity of S. cucurbitacearum infections in melon plants [34].…”

“…Indeed, lemongrass essential oil (Cymbopogon citratus) was shown to provide 100% inhibition of mycelial growth of S. cucurbitacearum [22,33]. Moreover, Dalcin et al [34] reported that treatment with a low concentration of lemongrass essential oil (<0.3%) reduced the severity of S. cucurbitacearum infections in melon plants.…”

Botanical and chemical fungicides in the treatment of commercial seeds of Brachiaria brizantha and Panicum maximum

“…As for noni essential oil, the literature has highlighted the antimicrobial effects of M. citrifolia against various pathogens, such as Aspergillus niger, A. fumigatus, Curvularia sp., Helminthosporium sp., Olivea neotectone, Pseudomonas sp., Rhizopus oryzae, Sclerotium sp. and Stagonosporopsis cucurbitacearum [22,23,42,42,43]. Even though in some cases noni essential oil had a toxic effect on seeds [22], fungal inhibition was proportional to the increase in concentrations.…”

Botanical fungicides in the control of soybean leaf diseases / Fungicidas botânicos no controle de doenças foliares na soja

“…They are plant origin volatile components naturally occurring and have strong antimicrobial and antioxidant potential (Prakash et al, 2015). The phytopathogenic fungi control with essential oils has been showing efficiency in studies carried out in several cultures, such as maize (Mourão et al, 2017), melon (Dalcin et al, 2017), bean plant (Hillen et al, 2012), tomato plant (Santos Neto et al, 2016), among others. Among the works carried out, can stand out the studies by Dalcin et al (2017), Silva et al (2017) and Osorio et al (2018) with noni (M. citrifolia L.).…”

“…The phytopathogenic fungi control with essential oils has been showing efficiency in studies carried out in several cultures, such as maize (Mourão et al, 2017), melon (Dalcin et al, 2017), bean plant (Hillen et al, 2012), tomato plant (Santos Neto et al, 2016), among others. Among the works carried out, can stand out the studies by Dalcin et al (2017), Silva et al (2017) and Osorio et al (2018) with noni (M. citrifolia L.). The plant contains phytochemicals with antibacterial, antiviral, antifungal, antitumor, anthelmintic, analgesic, hypotensive, anti-inflammatory and immunological effects.…”