ABSTRACT
Parsley (Petroselinumsativum L.) is one of the most important medicinal plants which belong to the family of Apiaceae and believed to be natives of the Eastern Mediterranean region. Parsley is infected with many foliar diseases, powdery mildew disease caused by Erysipheheraclei DC is considered one of the most important of these diseases, which is spread and attack plant in the different cultivation areas, causing severe damage to the vegetative crop. The typical symptoms of powdery mildew were observed on parsley during disease survey monthly at growing season, 2016/17, from January to April at four Fayoum governorate districts. In an attempt to control of this disease, there are several experiments conducted using safe materials in order to preserve human health and avoid environmental pollution but, without ignore the role of chemical control which can be used if need be. In-vitro experiments were conducted to assess the impact of using different concentrations of biocides (Plant-Guard, Bio-ARC 6 % and Biobac 50 %), plant extracts (moringa leaf, garlic cloves and bluegum leaf extracts), essential oils (citronella, thyme and anise) and induced resistance agents (Sodium bicarbonate, Ascorbic acid and Ammonium dihydrogen phosphate) besides two fungicides (Thiovit jet 80 % and Score 25 %) on conidiospore germination.
All the tested treatments achieved an obviously significant reduction to the spore germination of E. heracleicompared with reference to the control treatment. This reduction gradually increased by increasing the tested concentration. Among tested biocides, Biobac 50 % was the most efficient one being 61.95 % reduction to the spore germination followed by Bio-ARC 6 % (49.16 %), then Plant-Guard in descending order (32.88 %). Concerning plant extracts, garlic cloves extract was the superior antifungal activity against spore germination followed by moringa leaf extract, the corresponding percentages of reduction to the spore germination were recorded 47.98 and 36.85 %, respectively. Meanwhile, bluegum leaf extract in descending order (8.28 %).Among three essential oils tested, maximum reduction to the spore germination was recorded 66.06 % by thyme oil followed by anise oil (59.88 %), then citronella oil in descending order (46.62 %). Concerning induced resistance agents, the best antifungal activity against spore germination obtained by Ascorbic acid, is 60.51 % reduction to the spore germination followed by Sodium bicarbonate (53.82 %) then, Ammonium dihydrogen phosphate in descending order (22.85 %). Finally, complete inhibition in spore germination occurred by Score 25 % fungicide followed by Thiovit Jet 80 % (90.02 %).