O experimento foi conduzido no Departamento de Fitopatologia da Universidade Federal de Viçosa, sob condições controladas e de campo, num período de três anos. Mensalmente, 40 plantas de café com seis meses de idade, foram inoculadas com 1,0 mg/folha de uredosporos da raça II de Hemileia vastatrix, na face inferior das folhas de café, sendo que metade delas foram levadas diretamente para o campo, e a outra metade, foi colocada em câmara úmida à temperatura de 22 ± 2o C e umidade relativa superior a 95%, por 48 horas, antes de serem transferidas para o campo. Temperatura, chuva e molhamento foliar foram monitorados durante toda a condução do experimento. Condições de favorabilidade ao desenvolvimento da ferrugem foram determinadas considerando-se as variáveis meteorológicas. Observou-se que existe relação entre as condições de favorabilidade à infecção (temperaturas entre 20 e 25o C e presença de molhamento foliar) e o desenvolvimento da doença no campo. Assim, nos meses em que as condições climáticas eram favoráveis à infecção (de Novembro a Março), ocorreram os picos de severidade da doença e taxas crescentes de doença.
This experiment was studied the effect of weather conditions (temperature, rain and leaf wetness) on the occurrency and development of coffee leaf rust, under controllled and field conditions for three years, at the Plant Pathology Department of the Federal University of Viçosa. Fourty coffee plants of six months old were inoculated montly, with 1,0 mg/leaf of uredospores of the race II of H. vastatrix, on the abaxial side of the leaf. Fifty percent of the plants was removed directly to the field, and the other half was incubated in a humid chamber, at the temperature of 22 ± 2 C and relative humidity over 95 % for 48 hrs., before they were removed to the field. Temperature, rain and leaf wetness were monitored during the three years. The favorability of coffee leaf rust development were determined considering the meteorological variables. The results showed that there was a relation between conditions favorable for infection (temperature between 20 and 25o C and leaf wetness) and the development of the disease in the field. The months that the weather conditions were favorable to infection (from November to March) several peaks, and crescent infection rate of the disease was observed.
