Effects of Sunflower Oil on Tomato Powdery Mildew Caused by Oidium neolycopersici

Abstract

When tomato leaves were sprayed with 0.1% emulsified canola oil, corn oil, grape seed oil, peanut oil, safflower oil, soya bean oil or sunflower oil, the severity of powdery mildew caused by Oidium neolycopersici was greatly reduced. Among these edible oils tested, sunflower oil was the most effective in the control of powdery mildew. When sprayed with 0.5% sunflower oil, powdery mildew on tomato leaves was reduced to a negligible level. Sunflower oil applied to halves of upper leaf surface did not induce resistance against the pathogen in the non‐treated halves. When applied to halves of lower leaf surface, it also failed to reduce the severity of powdery mildew on the upper leaf surface right above the treated area indicating that control of the powdery mildew by sunflower oil did not result from activation of host defence mechanisms. Scanning electron microscopy showed that control of powdery mildew with sunflower oil resulted mainly from the inhibition of conidial germination and suppression of mycelial growth of the pathogen.

Control of powdery mildew on glasshousegrown roses and tomatoes in the Netherlands using anhydrous milk fat and soybean oil emulsions

“…SBO-14 provided significantly better (P<0.001) PM control than AMF-14 on tomato leaves. These results confirm the findings of Ko et al (2003) that plant oils have antifungal activity against PM on tomato.…”

Evaluation of the anti-Fusarium oxysporum f. sp cicer and anti-Alternaria porri effects of some essential oils

“…Several studies are going on to explore the potential of essential oils as antifungal agents (Ko et al 2003;Oxenham et al 2005). In this study, 75 essential oils have been studied against FOC and A. porri.…”

Control of silverleaf whitefly, cotton aphid and kanzawa spider mite with oil and extracts from seeds of sugar apple

“…0.2 cm each side) of leaf, each containing a nymph of silverleaf whitefly, were excised with a surgical scalpel under the dissecting microscope at 30x magnification, and adhered onto aluminum specimen mounts with double adhesive tape, immediately frozen in liquid nitrogen and dried in a vacuum chamber. Samples were then placed on the cryo-stage and viewed with a JSM-6330F field emission scanning electron microscope (Jeol, Tokyo, Japan) (Ko et al 2003).…”