The influence of temperature on germination of broomrape (Orobanche cumana Wallr.) seeds parasitizing on sunflower

The article presents the research on the germination speed of broomrape (Orobanche cumana Wallr.) seeds of highly virulent populations under different temperature conditions with root exudations of sunflower. It was determined that the optimum temperature for seeds germination of the studied populations is not lower than 25 °C. However, the seeds of these populations already didn’t germinate under 30 °C. Under 13 °C the seeds germination within 10 % was observed on the 17 th day after their soaking in the solution of root exudations of sunflower. It was also shown that broomrape populations can differ on seeds viability; the fact that is necessary to take into account when dosing the infection load.