5.2.58
PYTHIUM OLIGANDRUM AS A BIOCONTROL AGENT STIMULATING SEED-POTATO GERMINATION AND SUPPRESSING POTATO LATE BLIGHT PRIMARY INFECTION

D VESELY

Biologicals Ltd, Research Department, Unetice 150, 252 62 Horomen'ce, Prague-zapad, Czech Republic

Background and objectives
Pythium oligandrum Drechsler is an aggressive mycoparasite with a range of fungal hosts. Addition of the mycoparasite increases the weight of emerged crops and improves their state of health [1]. It also has potential to induce plant defence reactions [2].

Materials and methods
The top buds of seed-potato tubers were inoculated with suspended oospores of Pythium oligandrum daily, in comparison to control inoculation with steriled water in a laboratory experiment. Seed potatoes 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 inoculations with concentrations 1x103 or 3x104 of P. oligandrum caused germination, the growth of buds and the growth of rootlets to be stimulated when compared with sterile water control. It also slowed down development of symptoms of potato late blight primary infection.

References
1. Vesely D, 1977. Phytopathol. J. 90, 113-115.
2. Benhamou N, Rey P, Cherif M, Hockenhull J, Tirilly Y, 1997. Phytopathology 87, 108-122.