Effect of environmental conditions and inocolum concentration on sporulation of Peronospora destructor
Lithuanian Institute of Horticulture, Kauno str. 30, LT - 54333 Babtai, Kaunas distr.,Lithuania; e-mail: v.bandzeviciute@lsdi.lt
Abstract:
The effect of inoculum concentration, incubation time, relative humidity (RH) and temperature on sporulation of Peronospora destructor on onion leaves was analyzed under controlled environmental conditions in a greenhouse. The shortest period for spore germination and sporulation was on onion leaves inoculated with 106 spores/ml distilled water suspension. The intensity of infection and the sporulation of infected plants were affected greatly by the time and temperature of incubation. Exposure of inoculated plants at 15°C for 8 days and then at 22°C for 5 days resulted in the percentage of infection and the most abundant sporulation. Results of this experiment indicated that the period of P. destructor sporulation on one plant lasted 4–8 days.
Key words:
incubation, onion, Peronospora destructor, relative humidity, sporulation, temperature