Effective Management of Cucumber Powdery Mildew with Essential Oils

Abstract

This research evaluated the efficacy of essential oils in the management of cucumber powdery mildew. Essential oils of lemongrass, lemon, thyme, peppermint, abundance blend, purification blend, and thieves blend were tested in vitro and under greenhouse conditions in two separate experiments. The effects of essential oils were tested against powdery mildew disease at concentrations of 1.0–2.5 mL/L, and the consequent impact of the oils on plant growth was evaluated. Powdery mildew fungus, Podosphaera xanthii, was identified using sequencing of the ITS region. The essential oils significantly reduced disease incidence up to 77.3% compared with the positive control (p < 0.5). Moreover, the essential oils increased the plant length (up to 187 cm), leaf area (up to 27.5 cm2), fresh weight (up to 123 g), dry weight (up to 22.5 g), number of flowers (16.3), and metabolite content compared with the positive control (p < 0.5). Cell membrane injury decreased significantly in the oil-treated pants (p < 0.5), indicating the protective effect of essential oils. This study recommends the application of essential oils in an appropriate dose (2.5 mL/L) to protect cucumber plants against powdery mildew. Overdose of the oils (more than 2.5 mL/L) should be avoided due to adverse effects.

Effects of synthetic and environmentally friendly fungicides on powdery mildew management and the phyllosphere microbiome of cucumber

“…phyllosphere microbial community while achieving the same control efficacy as the synthetic fungicide tebuconazole. Many environmentally friendly control agents have been tested for cucumber, and the results suggest no significant differences in efficacy relative to synthetic fungicides [12,15,16]. Consistent with these previous studies, we observed that both the plant elicitor NPA and the ancient plant disease control agent sulfur effectively controlled powdery mildew on cucumber and displayed no significant differences from tebuconazole.…”

“…At present, the use of environmentally friendly fungicides has been proposed as a substitute for the application of synthetic fungicides, especially for organic farming. The environmentally friendly fungicides that control cucumber powdery mildew include neutralized phosphorous acid (NPA), sulfur, potassium bicarbonate, emulsified oil [12], and other biological control agents. NPA is an elicitor of the plant defense response [13] and has been suggested to effectively control powdery mildew caused by P. xanthii [14][15][16] and Oidium sp.…”

Biocontrol of Sphaerotheca fuliginea, the causal agent of powdery mildew of cucumber by using aqueous extracts from five traditional Egyptian medicinal plants

“…Over the past several years, there has been an increase in the quest for plant extracts with anti-ascomycete activity. These studies have shown that plant extracts are effective against S. fuliginea, the fungal pathogen that causes the powdery mildew disease that affects Cucurbitaceae (Al Surhanee 2013;Guginski-Piva et al 2015;Abdu-Allaha and Abo-Elyousr 2017;El-Ghanam et al 2018;Mostafa et al 2021a) There are several ways that plants defend themselves from diseases, such as phenolic complexes, which are secondary plant metabolites. These substances can be found in the root, rhizome, shoot, leaf, and flower of the plant (Houssien et al 2010).…”

“…Numerous scientists have hypothesized that plant pathogens lead to an increase in phenolic chemicals and related defense enzymes in plants (Bhattacharya et al 2010;Baka et al 2013;Mianabadi et al 2015;Mostafa et al 2021aMostafa et al , b 2022. According to some researchers, spraying crops with a lot of plant extracts increased agricultural production (Mvumi et al 2013;Elzaawely et al 2017;Bello et al 2022).…”

Distinguishing Pickled and Fresh Cucumber Slices Using Digital Image Processing and Machine Learning

“…It has a favorable flavor and texture, as well as medicinal values, including antioxidant ability, antimicrobial activity, and the ability to lower glycemic levels. Eating cucumber may be beneficial in improving immunity, boosting the metabolism, and reducing the risks of cancers [2][3][4]. Therefore, it is often eaten both fresh, e.g., in salads, and processed or preserved, e.g., as pickles.…”