Molecular epidemiology and management of postbloom fruit drop of citrus in new planting areas in São Paulo State

• Grant number: 08/54176-4
• Support Opportunities: Research Projects - Thematic Grants
• Start date: December 01, 2008
• End date: November 30, 2013
• 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
• Pesquisadores principais: Marcel Bellato Spósito
• Associated research grant(s): 13/50116-5 - Improved PFD control in São Paulo and Florida: using weather forecasts to anticipate disease risk in citrus groves, AP.R
• Associated scholarship(s): 11/20472-9 - Dispersal of Colletotrichum acutatum and C. gloeosporioides, causal agents of postbloom fruit drop: would be insects the responsible agents for pathogen spread over long distances?, BP.PD; 10/09012-3 - Monocycle, population survey and reduction of initial inoculum on Postbloom fruit drop, BP.PD; 09/03224-1 - Pathogenic specificity and vegetative compatibility between Colletotrichum acutatum isolated from citrus and other hosts, BP.MS; 09/00425-6 - Postbloom fruit drop of citrus: histopathology of Colletotrichum acutatum, BP.DR

Abstract

Citrus crop in São Paulo State is migrating from North and Central regions that concentrate 75% of citrus production to new areas in the Southeast. The objective of this migration is to keep citrus production as a profitable business (Neves et aI., 2007). The main reasons for the migration are: lower values of land in Southeast region, compared to traditional planting areas, and lower costs of production (Neves & Jank, 2006; Tozatti, 2007). In the Southeast region irrigation (an expensive culture management) is not needed as there is a high frequency of rainy days. In these new circumstances, under different environment, citrus will need new strategies for crop management. Weather in this region is favorable to the occurrence of postbloom fruit drop (Tozatti, 2007), caused by Colletotrichum acutatum. This disease is not important in other regions of São Paulo State (Northeast/North and Centre) because of its sporadic occurrence, but it is considered the main disease in the Southeast region (Feichtenberger et al., 2005). This disease can cause the drop of up to 100% of young fruit. For this reason its control is absolutely necessary in orchards where it occurs frequently. Control of postbloom fruit drop is made by preventive fungicide spraying during bloom. Costs of chemical treatment to control postbloom fruit drop are estimated in US$ 553/ha, considering that one tractor is used for 50 ha (Salvo Filho, 1994). Preventive control of the disease exclusively based on the phenological host stage commonly causes excessive fungicide spraying with adverse effects to the environment. The continuous application of the same fungicide (or active ingredient) in an orchard frequently selects resistant strains of the pathogen. In this case the fungicide becomes inoperative. In order to improve disease management and to reduce the cost of fungicide spraying, epidemiological behavior of the pathosystem must be known. There is very few information available on the epidemiology of postbloom fruit drop of citrus. Most of them were produced in Central America and USA. It is still unknown in the State of Sao Paulo the way and the period of inoculums survival between blooming, the environmental conditions favorable to infection, the inoculums variability inside the orchards and the specificity of C. acutatum isolates to Citrus species. It has not been determined as well the pattern and distances of inoculums dispersal, influence of weather variables to the disease progress and spatial distribution of diseased plants. Considering the lack of information in Sao Paulo State, it is not surprising that forecast systems developed in Florida to control this disease have not been adopted by citrus growers from São Paulo. The main objectives of this project are: (i) to characterize the spatial distribution of the inoculums and the disease progress in orchards at the Southeast region of Sao Paulo State; (ii) to understand different phases of disease cycle, particularly the mechanisms of inoculums survival, pathogen variability and pathogen infection and colonization; (iii) to test different alternatives to the chemical control that is used by growers and validate/develop disease forecasts systems adapted to the Sao Paulo conditions. (AU)

Scientific publications

(12)

(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)

FRARE, G. F.; COUTO, H. T. Z.; CIAMPI-GUILLARDI, M.; AMORIM, L.. The causal agent of citrus postbloom fruit drop, Colletotrichum acutatum, can survive on weeds. AUSTRALASIAN PLANT PATHOLOGY, v. 45, n. 4, p. 339-346, AUG 2016. (08/54176-4)

MARQUES, JOAO PAULO R.; AMORIM, LILIAN; SPOSITO, MARCEL B.; APPEZZATO-DA-GLORIA, BEATRIZ. Ultrastructural changes in the epidermis of petals of the sweet orange infected by Colletotrichum acutatum. PROTOPLASMA, v. 253, n. 5, p. 1233-1242, SEP 2016. (09/00425-6, 08/54176-4)

RODRIGUES MARQUES, JOO PAULO; AMORIM, LILIAN; SPOSITO, MARCEL BELLATO; MARIN, DENIS; APPEZZATO-DA-GLORIA, BEATRIZ. Infection of citrus pollen grains by Colletotrichum acutatum. European Journal of Plant Pathology, v. 136, n. 1, p. 35-40, MAY 2013. (09/00425-6, 08/54176-4)

SILVA-JUNIOR, G. J.; SPOSITO, M. B.; MARIN, D. R.; RIBEIRO-JUNIOR, P. J.; AMORIM, L.. Spatiotemporal characterization of citrus postbloom fruit drop in Brazil and its relationship to pathogen dispersal. PLANT PATHOLOGY, v. 63, n. 3, p. 519-529, JUN 2014. (08/54176-4)

CIAMPI, M. B.; BALDAUF, C.; VIGNA, B. B. Z.; SOUZA, A. P.; SPOSITO, M. B.; AMORIM, L.. Isolation and characterization of microsatellite loci in Colletotrichum acutatum, the causal agent of postbloom fruit drop on citrus. CONSERVATION GENETICS RESOURCES, v. 3, n. 4, p. 651-654, OCT 2011. (08/54176-4)

CIAMPI-GUILLARDI, MAISA; BALDAUF, CRISTINA; SOUZA, ANETE PEREIRA; SILVA, GERALDO JOSE; AMORIM, LILIAN. Recent Introduction and Recombination in Colletotrichum acutatum Populations Associated with Citrus Postbloom Fruit Drop Epidemics in Sao Paulo, Brazil. PHYTOPATHOLOGY, v. 104, n. 7, p. 769-778, JUL 2014. (08/54176-4)

GASPAROTO, M. C. G.; LOURENCO, S. A.; TANAKA, F. A. O.; SPOSITO, M. B.; MARCHINI, L. C.; SILVA JUNIOR, G. J.; AMORIM, L.. Honeybees can spread Colletotrichum acutatum and C-gloeosporioides among citrus plants. PLANT PATHOLOGY, v. 66, n. 5, p. 777-782, JUN 2017. (11/20472-9, 08/54176-4)

GONCALVES, FABRICIO PACKER; NOGUEIRA JUNIOR, ANTONIO F.; SILVA-JUNIOR, GERALDO JOSE; CIAMPI-GUILLARDI, MAISA; AMORIM, LILIAN. Environmental requirements for infection of Colletotrichum acutatum and C. gloeosporioides sensu lato in citrus flowers and prevalence of these pathogens in Brazil. European Journal of Plant Pathology, v. 160, n. 1, FEB 2021. (08/54176-4)

RODRIGUES MARQUES, JOAO PAULO; SPOSITO, MARCEL BELLATO; AMORIM, LILIAN; MONTANHA, GABRIEL SGARBIERO; SILVA JUNIOR, GERALDO JOSE; PEREIRA DE CARVALHO, HUDSON WALLACE; APPEZZATO-DA-GLORIA, BEATRIZ. Persistent Calyxes in Postbloom Fruit Drop: A Microscopy and Microanalysis Perspective. PATHOGENS, v. 9, n. 4, APR 2020. (15/05942-0, 08/54176-4, 15/19121-8)

SILVA-JUNIOR, GERALDO JOSE; SPOSITO, MARCEL BELLATO; MARIN, DENIS ROGERIO; AMORIM, LILIAN. Efficacy and timing of application of fungicides for control of citrus postbloom fruit drop. CROP PROTECTION, v. 59, p. 51-56, MAY 2014. (08/54176-4)

LIMA, WALERIA GUERREIRO; SPOSITO, MARCEL BELLATO; AMORIM, LILIAN; GONCALVES, FABRICIO PACKER; MELO DE FILHO, PERICLES ALBUQUERQUE. Colletotrichum gloeosporioides, a new causal agent of citrus post-bloom fruit drop. European Journal of Plant Pathology, v. 131, n. 1, p. 157-165, Sept. 2011. (08/54176-4)

RODRIGUES MARQUES, JOAO PAULO; MISAKI SOARES, MARLI KASUE; APPEZZATO-DA-GLORIA, BEATRIZ. New staining technique for fungal-infected plant tissues. TURKISH JOURNAL OF BOTANY, v. 37, n. 4, p. 784-787, 2013. (09/00425-6, 08/54176-4)