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PYTHIUM OLIGANDRUM AS A BIOCONTROL AGENT STIMULATING THE SEED-POTATO GERMINATION AND SUPPRESSING THE POTATO LATE BLIGHT PRIMARY INFECTION
PYTHIUM OLIGANDRUM AS A BIOCONTROL AGENT STIMULATING THE SEED-POTATO GERMINATION AND SUPPRESSING THE POTATO LATE BLIGHT PRIMARY INFECTION D VESELY 1 Biologicals Ltd, Research Department Unetice 150, 252 62 Horomen'ce, Prague-zapad, Czech Republic Background and objectives Pythium oligandrum Drechsler characterized as an aggressive parasite with 'de range of fungal hosts 's able to increase the weight of emerged crops and to a wi 1 improve their state of health by the addition of the mycoparasite [ 1 ] and has a potential to induce plant defence reactions [ 2 ]. Materials and methods The top-germs of seed-potato tubers were dropped with suspended oospores of Pythium oligandrum daily compared with dropping by steriled water in the laboratory experiment. Seed-potato were dressed with dried Pythium oligandrum oospores and crops were sprayed once with the water suspension of oospores on the surface of leaves of emerged potato plants in the small-plot field experiment. Results and conclusions The daily droppings with concentrations 1 X 103 or 3 x 104 of Pythium oligandrum [ 2 ml suspension on the surface of top-germ in seed-potato tubers ] effected the germination, the growth of this germ and the growth of rootlets positively if compared with sterile water in the laboratory experiment. The biological control [ seed-potato dry-dressing with oospores of Pythium oligandrum - one tuber infested with 50 oospores - and one fohar application with [ 0.05 % ] water suspension of oospores 1 delayed and slowed down the symptoms of potato late blight primary infection. References 1. Vesely D, 1977. Phytopathol. J. 90, 2, 113 - 115. 2. Benhamou N, Rey P, Cherif M, Hockenhull J, Tirilly Y, 1997. Phytopathology 87, 108 - 122.