Development and establishment of an on-line forecast system for citrus postbloom fruit drop epidemics

• Grant number: 14/19933-0
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2014
• End date: November 30, 2016
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Lilian Amorim
• Grantee: Lilian Amorim
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated researchers: Angelica Giarolla ; Chou Sin Chan ; Geraldo José da Silva Junior ; Josiane Ferreira Bustamante Fonseca ; Natália Aparecida Rodrigues Peres

Abstract

Control of postbloom fruit drop (PFD) of citrus in the southwestern region of São Paulo state, where PFD is more prevalent, has been achieved using preventive, calendar-based fungicide applications. While PFD occurs frequently in the region, infection levels vary significantly, causing high losses when winters are rainy such as in 2009, and not affecting production during years with drier winters, with few and low-intensity rainfall events. High levels of infection are not the rule and intensive control with calendar-based fungicide applications is not required when climate conditions do not favor PFD occurrence. Disease alert systems are designed to optimize fungicide applications, recommending spraying only when conditions are favorable for infection. The main objective of this research project is to develop and implement a PFD alert system aimed at helping citrus growers in southwestern São Paulo to optimize fungicide applications. The system will be based on the results obtained during the thematic project 2008/54176-4, at which the conditions that favor PFD occurrence during different flower development stages were determined. The proposed project will be implemented in four sequential activities or tasks: 1 - Determination of the best methodology to estimate wetness duration (wetness sensors or mathematical models) to be used in the disease alert system; 2- Determination of thresholds to recommend spraying in the southwestern region of São Paulo; 3 - Evaluate the accuracy and precision of the weather forecast for the region of interest provided by the "Instituto Nacional de Pesquisas Espaciais (INPE)"; 4- Development and implementation of a web-based disease risk alert system. The project team is interdisciplinary with expertise in PFD epidemiology and weather/climate forecast systems, and from different institutions: ESALQ-USP, Fundecitrus, CPTEC-INPE, and the University of Florida. Expected project outcomes include a web-based and field-validated PFD alert system of easy access and understanding by citrus growers that will also include smartphone alerts of current and expected disease risk levels based on the weather forecast. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

GAMA, ANDRE B.; SILVA JUNIOR, GERALDO JOSE; PERES, NATALIA A.; MOLINA, JUAN EDWARDS; DE LIMA, LILIAN M.; AMORIM, LILIAN. A Threshold-Based Decision-Support System for Fungicide Applications Provides Cost-Effective Control of Citrus Postbloom Fruit Drop. PLANT DISEASE, v. 103, n. 9, p. 2433-2442, SEP 2019. (14/19933-0, 15/06007-2)