Coffee Science_v.18, 2023
URI permanente para esta coleção${dspace.url}/handle/123456789/13916
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Item New vegetation index for monitoring coffee rust using sentinel-2 multispectral imagery(Universidade Federal de Lavras, 2023-12-29) Castro, Gabriel Dumbá Monteiro de; Vilela, Emerson Ferreira; Faria, Ana Luísa Ribeiro de; Silva, Rogério Antônio; Ferreira, Williams Pinto MarquesCoffee Rust (Hemileia vastatrix) is considered the primary coffee disease in the world. The pathogenic fungus can find favorable environmental conditions in different countries, constantly threatening coffee producers. The previous detection of the incidence of coffee rust in a region is crucial because it provides an overview of the disease’s progress aiding in coffee plantations management. The objective of this work was the development of a vegetation index for remote monitoring of coffee rust infestation. Using satellite images from the MSI/Sentinel-2 collection, the Machine Learning classifier algorithm - Random Forest, and the cloud processing platform - Google Earth Engine, the most sensitives bands in coffee rust detection were determined, namely B4 (Red), B7 (Red Edge 3) and B8A (Red Edge 4). Thus, the Triangular Vegetation Index method was used to create a new vegetative index for remote detection of coffee rust infestation on a regional scale, named Coffee Rust Detection Index (CRDI). A linear regression model was created to estimate rust infestation based on the performance of the new index. The model presented a coefficient of determination (R²) of 62.5%, and a root mean square error (RMSE) of 0.107. In addition, a comparison analysis of the new index with eight other vegetative indices commonly used in the literature was carried out. The CRDI obtained the best performance in coffee rust detection among the others. This study shows that the new index CRDI has the robustness and general capacity to be used in monitoring coffee rust infestation on a regional scale.Item Temporal progress of coffee leaf rust and environmental conditions affecting severity in Veracruz State, Mexico(Universidade Federal de Lavras, 2023-03-28) Pale-Ezquivel, Ivan; Lagunes, Ricardo Musule; Pineda-López, Maria del Rosario; Alarcón-Gutiérrez, Enrique; Sánchez-Velásquez, Lázaro RafaelCoffee is an important crop in Mexico. Unfortunately, coffee production has been affected by coffee leaf rust (CLR). For Veracruz, the second state in Mexico with the major production of coffee, there are available reports of weekly CLR severity, but these are only informative without in-depth inferential analysis. We analyzed variations of CLR severity along the year in Veracruz with data from municipal weekly reports provided by Mexico’s federal government phytosanitary epidemiological monitoring coffee program. We selected reports dated in 2018 from nine municipalities and after calculations of mean monthly severity values, we conducted a one-way ANOVA (months as factors) of severity data. We compared this information with other coffee-producing regions. Additionally, we explored the association of temperature, rainfall, and altitude with CLR severity using Principal Component Analysis and multiple linear regressions. Temperature and rainfall data were obtained from Mexican National Meteorological Service. We found that CLR severity in October, November, December, and January (months of harvest period) was significantly higher than values from March-June. During the harvest period, coffee plants allocate resources mainly for fruiting which competes in resources for other tasks such as defense and leaf growth, so this competition of resources can explain the positive relationship found between fruit load and CLR severity. This monthly variation of severity was similar to those reported in Chiapas, Guatemala, Colombia, Uganda, and Ethiopia. Our model (R2 = 0.948) showed a significant and negative effect of minimum and maximum temperature (in a range from 9.9 – 15.5 °C and 18.5 – 26.5 °C, respectively) on CLR severity, while the effect of rainfall (in a range from 32.0 – 359.9 mm) and médium temperature (from 14.3 – 20.5 °C) was positive. With our study, we suggest applications of fungicides in March-June when coffee plantations are in leaf phenophase.