Dispersal pattern of Colletotrichum acutatum and efficiency of fungicides to control citrus postbloom fruit drop under rain tunnel

• Grant number: 11/21472-2
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: January 10, 2012
• End date: April 09, 2012
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Lilian Amorim
• Grantee: Fabrício Packer Gonçalves
• Supervisor: Natália A. Peres
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Institution abroad: University of Florida, Gainesville (UF), United States
• Associated to the scholarship: 10/09012-3 - Monocycle, population survey and reduction of initial inoculum on Postbloom fruit drop, BP.PD

Abstract

Some aspects of the Thematic Project (Process FAPESP 2008/54176-4) related to chemical control and dispersal of Colletotrichum acutatum, causal agent of postbloom fruit drop (PFD) has not been studied. The disease chemical control is often performed in the presence of the rain in the Southwest region of São Paulo State. Nevertheless, no studies have been conducted to determine the retention of fungicides in citrus flowers in the presence of rain. C. acutatum is a pathogen that has limited dispersal and needs rain for its spread. However, recent results from three harvests (Silva Jr., 2011) showed a random spatial pattern of the disease in the field when the conditions are favorable. This unexpected behavior of the disease in the field indicates a greater contribution from the wind or other agents in the spread of C. acutatum. Thus, this project has the following aims: (i) to evaluate the effect of rain on the efficiency of chemical control applied before, during and after simulated rain and (ii) to quantify the spread of the pathogen in the presence of the wind and the wind plus rain. The experiments will be conducted at University of Florida under the supervision of Professor Dr.ª Natália A. Peres. Professor Peres is widely recognized as an expert and leader in research with C. acutatum. Besides, she is responsible for a rainfall simulator under plastic tunnel, which will be transformed into a wind tunnel with addition of exhaust fans. This structure is essential for carrying out experiments involving rainfall simulation and dissemination of the pathogen. (AU)