RELATION BETWEEN INOCULUM CONCENTRATION OF CRONARTIUM FLACCIDUM AECIDIOSPORES AND UREDIA AND TELIA PRODUCTION ON VINCETOXICUM HIRUNDINARIA LEAVES

The Authors have carried out an experiment to test the effect of concentration of inoculum of aecidiospores of Cronartium flaccidum on the production of uredia and telia on leaves of Vincetoxicum hirundinaria. The trials were carried out under controlled and field conditions. The best results is achieved with the concentration of 10,000 aecidiospores/ml in controlled conditions and of 100,000 aecidiospores/ml in field conditions. The youngest leaves are the most productive. We obtained the highest number of sori with inoculations made in the field conditions in the month of July. In conclusion, to have inoculum (basidiospores under controlled conditions) even if their germinative capacity is low, it is necessary to proceed with inoculations with suspension of 10,000 aecidiospores/ml, at night-day regime: 15-25°C; 85-65% r.h.; 0-8,000 lux. However, in field conditions we have achieved positive results only in a period relating to natural production of sori (from June to September). Gli Autori hanno saggiato l'effetto della densità dell'inoculo (ecidiospore) di Cronartium flaccidum sulla produzione di uredo e teleuto sulle foglie di Vincetoxicum hirundinaria. Le esperienze sono state condotte in natura e in condizioni controllate: la concentrazione ottimale è stata, rispettivamente, di 100.000 e 10.000 ecidiospore/ml. Le foglie più giovani sono le più produttive. Infine, per avere basidiospore in condizioni controllate, occorre usare concentrazioni di 10.000 ecidiospore/ml con il regime seguente: 15-25°C; 85-65% u.r.; 0-8.000 lux.