Spatial and temporal behavior of coffee rust in C. canephora and its effects on crop yield

Coffee rust has been one of the main factors responsible for reducing crop yield. The management of this disease corresponds to one of the main costs in the production chain of C. canephora and often the practices adopted by farmers are not able to minimize production losses. Therefore, it is important to adopt methodologies that help the sustainable management of the disease in the field, reducing losses in yield and costs with pesticide applications. This study aimed to monitor coffee rust (Hemileia vastatrix Berk. & Br.) in a commercially grown crop with C. canephora Pierre ex Froehner, associating the effect of disease severity on different phenological phases of plants on the crop yield. Data collection of rust severity and plant yield was performed using an irregular sampling grid with 120 points, which was set up in the area for monthly samplings. Geostatistical analysis was used to determine and quantify the spatial variability of the disease severity. To describe the joint effect of the severity of rust from different periods on coffee yield, a principal component analysis was used. The disease influence on coffee yield was assessed using Spearman’s linear correlation analysis. The rust occurred in practically all the evaluated months, however the highest averages of severity were observed between the months of March and September. Furthermore, the temporal behavior of disease was very influenced by the weather conditions. The occurrence of rust showed spatial dependence and its occurrence in the phenological phases of flowering and fruit filling negatively influenced coffee yield.