Progresso temporal da cercosporiose em clones de café canéfora

Abstract

The selection of clonal varieties resistant to diseases is one of the main alternatives for the efficient management of diseases in coffee plantations. Thus, this study sought to evaluate the temporal progression curves of cercospora disease in clones of coffee canéfora. The experiment was conducted at the Fazenda Experimental Mangabeira, of the Federal University of Amazonas, located in Humaitá - AM. A randomized block design was used, with fifteen treatments, four repetitions, each repetition being composed of eight plants, of which the central four were considered useful. The treatments consisted of fifteen clones, five inter-varietal hybrids from the Conilon Encapa 03 x Robusta - 640, 1675 and 2258 matrices: BRS 1216, BRS 2314, BRS 3210, BRS 3213 and BRS 3220. Another four clones of the multiclonal Conilon cultivar BRS Ouro Preto: BRS 2299, BRS 57, BRS 125 and BRS 160, and six open-pollinated clones: BRS 2336, BRS 3137, BRS 3193, BRS 2357, Clone 09 and Clone 15. The symptoms were evaluated in eight leaves per plant, in the middle third, between the 3rd and 4th pair of leaves, from the apex of the plagiotropic branches. The percentage of incidence was determined according to the number of leaves with symptoms in relation to the total number of leaves sampled. To quantify the severity of cercospora we used a diagrammatic scale, ranging from 1 to 6 levels, based on the area of the lesion. The results were submitted to variance analysis and the means were compared using the Scott-Knott test at 5% probability. Significant interaction was observed between sample months and clones, when evaluating the incidence and severity of cercospora (p-value <0.05). The highest percentages of disease intensity were observed during the months of August/2021 to December/2022, especially in clones from open pollination and from the multiclonal Conilon cultivar BRS Ouro Preto. The results show that the environmental conditions present in the Amazon region are intrinsically favorable for the development of the disease. Therefore, the monitoring of the temporal progress of cercospora and the use of clones from Conilon and Robusta matrices are promising alternatives to increase the economic, social, and environmental sustainability of coffee growing in the Amazon.