Evaluation of the use of alternative control methods of coffee tree diseases in the tropical Amazon

Abstract

The present study aimed to evaluate the effect of alternative products on the control of coffee brown-eye spot and coffee rust. The experiment was carried out in two conilon coffee plantations, in the following agroforestry system models: a) continuous system (SM-1) and b) mixed system (SC-2). The following treatments were used: i) aqueous plant extract of Himatanthus sucuuba (2%) - SUC, ii) Bordeaux mixture (2%) - CB and iii) control (water). Four monthly samplings of the temporal progress of the diseases were carried out, during the period from October/2019 to January/2020, evaluating the symptoms in three leaves per plant, one from each of the upper, middle and lower thirds of the plant. Incidence percentages were determined according to the number of leaves with symptoms in relation to the total number of leaves sampled. In order to estimate severity, diagrammatic scales were used for each disease evaluated. The obtained data were submitted to routine statistical analysis in R programming with a significance of 5%. Interaction effects were not significant according to the ANOVA test. Significant differences were observed among the treatments studied for the two diseases with the following results: percent reduction of rust incidence: (SUC - 50%, CB - 80% and TEST - 95%) and percent reduction of brown-eye spot: (SUC - 30%, CB - 60 % and TEST - 80%). SUC treatment was more effective in reducing disease severity with the following results: (SUC - 0.26%, CB - 0.40% and TEST - 0.83%) and (SUC - 0.35%, CB - 0.41% and TEST - 0.99%) for rust and brown-eye spot diseases, respectively. The treatment (SUC) proved to be a promising alternative product for the management of brown-eye spot and rust diseases.