Emulsification Characters of COY (Cooking Oil and Egg Yolk Mixture) and Mixing Application with Sulfur Wettable Powder for Enhancing the Control Efficacies against Paprika Powdery Mildew

Emulsification characters were investigated for COY (Cooking oil and Egg Yolk Mixture) and control efficacies of COY was enhanced by supplemented Sulfur wp. against paprika powdery mildews. Amount of water added to one egg yolk and 100 ml olive oil affected tbe homogenization of mixtures to emulsion profoundly; those premixes with 5~10 ml water were too concentrated to be homogenized, hence not dispersible in water; those with 15~20 ml water were homogenized, but tended to flocculation and not readily dispersible in water, suggesting the instability of emulsion; and those with 50 or 100 ml water were homogenized well and was readily dispersible in water to stable emulsion over long period of time. It was further confirmed that those fruits sprayed with not-fully emulsified COY revealed the oily membranes or blotches on their surfaces, whereas the ones with fully emulsified COY revealed normal clean surfaces. Treatment of COY either alone or in supplementation with Sulfur wettable powder (sulfur wp) were also effective in suppressing the recurrence of powdery mildew signs, wbich had disappeared in three days of foliar application. Still, the COYs supplemented with sulfur wp (COY+sulfur wp) at 1,000x or 5,000x were significantly effective in suppression against the symptomlsign recurrence over COY or sulfur wp alone.