A. S. Capucho

Identification of a new race of Hemileia vastatrix in Brazil

In this study, a survey of physiological races of Hemileia vastatrix was carried out on 34 coffee leaf rust populations collected at several coffee genotypes in Brazil. After the inoculation on leaf disc of coffee differential clones, the races I, II, III, XIII, XVII and XXXVII were characterised. This is the first report of race XXXVII on Coffea arabica in Brazil, which shows the evolutionary potential of H. vastatrix. The emergence of complex races like XXXVII represents a challenge for breeders in the development of resistant cultivars.

Identification of race XXXIII of Hemileia vastatrix on Coffea arabica Catimor derivatives in Brazil

In this study, a survey of physiological races of H. vastatrix was carried out on 64 coffee leaf rust samples from genotypes of Coffea arabica, C. canephora and Híbrido de Timor/Icatu derivatives that are cultivated in Brazil’s main production areas. Based on the infection pattern in a series of differentiating coffee tree clones, the races I, II, III and XXXIII were characterised. The H. vastatrix race XXXIII, reported here for the first time, was associated under field conditions with infection of Catimor derivatives, which are generally considered resistant to coffee leaf rust.

Effect of foliar application of potassium silicate on the progress of coffee leaf rust

In order to evaluate the effect of potassium silicate spray on the control of coffee leaf rust and coffee yield, an experiment was conducted during the 2005/2006 and 2006/2007 growing seasons on Coffea arabica cv. Catuai Vermelho IAC 144, in a location situated at an elevation of 850 m in Coimbra, Minas Gerais, Brazil. The treatments consisted of: 1 - potassium silicate; 2 - potassium silicate + copper hydroxide; 3 - copper hydroxide; 4 - epoxiconazole formulated with pyraclostrobin and 5 - control treatment. Six applications of potassium silicate and copper hydroxide were made twice per month from December to March of each year. Two applications of the systemic fungicide were done in December and March of each year. Potassium silicate alone or in combination with copper hydroxide was not efficient in reducing coffee leaf rust incidence and increasing yield under high incidence of coffee leaf rust.

First report of teak leaf rust disease caused by Olivea tectonae in Brazil

This note reports the first occurrence of teak leaf rust disease caused by Olivea tectonae in Brazil. High severity of teak leaf rust was found on leaves of ornamental plants in the state of Minas Gerais and Espirito Santo, Brazil.

First report of Pseudocercospora muntingiae on Muntingia calabura in Brazil

Pseudocercospora muntingiae is recorded as the cause of leaf spots on Muntingia calabura (Tiliaceae), for the first time from Brazil and also in South America.