Relationships between leaf temperature, Brevipalpus phoenicis populations and coffee ringspot disease

• Grant number: 14/02960-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2014
• End date: April 30, 2015
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Daniel Júnior de Andrade
• Grantee: Matheus Mancini Porfirio Nunes
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

The mite Brevipalpus phoenicis (Geijskes) is one the most important pests of coffee plants because of its involvement in the transmission of the coffee ringspot virus (CoRSV) that causes the coffee ringspot disease, one of the most severe diseases of Brazilian coffee. The main objective of this project will be to study the relationships of cause and effect between leaf temperature and infestation of B. phoenicis viruliferous and non-viruliferous to CoRSV and the severity of coffee ringspot in coffee plants under different hydric conditions. The study will be performed in a greenhouse and laboratories belonging to the College of Agricultural and Veterinary Sciences (FCAV/UNESP), Jaboticabal campus. Plants under four levels of field capacity: 25, 40, 55, and 70%, will be arranged in three groups: (1) infestation with viruliferous mites, (2) infestation with non-viruliferous mites, and (3) no mite infestation. The experimental design is a randomized block in factorial design consisting of (A) soil at 25, 40, 55, and 70% of the capacity field and (B) plants with viruliferous mites, non-viruliferous mites, and no mite infestation. Average leaf temperatures will be measured daily after the start of the experiment by using a portable infrared thermometer. The daily stress index will be calculated, and the severity of coffee ringspot in the plants will be determined after the colonization of the mites. After the experiment is completed, the mites on the leaves will be removed and counted. Leaf samples will be collected to determine the levels of foliar nutrients. Data for the severity of coffee ringspot due to B. phoenicis and foliar nutrients will be subjected to analysis of variance by using the F test, and the mean values will be compared using Tukey's test. The data of leaf temperature will be correlated to the number B. phoenicis and the severity of coffee ringspot. (AU)