Spatiotemporal characterization of citrus postbloom fruit drop in Brazil and its relationship to pathogen dispersal

Autor(es)

Silva-Junior, G. J. ^{[1, 2]} ; Sposito, M. B. ^[1] ; Marin, D. R. ^[2] ; Ribeiro-Junior, P. J. ^[3] ; Amorim, L. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Plant Pathol, BR-13418900 Piracicaba, SP - Brazil

^[2] Fundecitrus, Dept Res & Dev, BR-14801970 Araraquara, SP - Brazil

^[3] Univ Fed Parana, Dept Stat, BR-81531990 Curitiba, PR - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLANT PATHOLOGY; v. 63, n. 3, p. 519-529, JUN 2014.
• Citações Web of Science: 12

Resumo

Citrus postbloom fruit drop (PFD) is caused by Colletotrichum acutatum and C.gloeosporioides. These pathogens attack the flowers and cause premature fruit drop and the retention of fruit calyces. This study was designed to characterize the spatial and temporal dynamics of PFD in commercial citrus-growing areas to better understand the disease spread. Experiments were carried out in three young orchards (500 trees each) in two municipalities in Sao Paulo State, Brazil. Symptoms of PFD on the flowers and presence of persistent calyces were assessed in each of three orchards for threeyears. Logistic, Gompertz and monomolecular models were fitted to the incidence data over time from the trees with symptoms. The spatial pattern of diseased trees was characterized by a dispersion index and by Taylor ` s power law. An autologistic model was used for the spatiotemporal analysis. The logistic model provided the best fit to the disease incidence data, which had a fast progress rate of 0 center dot 53 per day. During the early epidemic of PFD, the spatial pattern of diseased trees was random, which suggested that inoculum spread was due to mechanisms other than rain splash. As the disease incidence increased (up to 12 center dot 6%), the spatial pattern of diseased trees became aggregated. The rapid rate of disease progress and the distribution of PFD suggest that dispersal of the pathogen is possibly related to a mechanism other than splash dispersal, which is more typical of other fruit diseases caused by Colletotrichum spp. (AU)

• Processo FAPESP: 08/54176-4 - Epidemiologia molecular e manejo da podridão floral dos citros em áreas de expansão da cultura no estado de São Paulo
• Beneficiário: Lilian Amorim
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 08/54599-2 - Sensibilidade de populacoes de colletotrichum acutatum a fungicidas e manejo da podridao floral dos citros em areas de expansao da cultura no estado de sao paulo.
• Beneficiário: Geraldo José da Silva Junior
• Modalidade de apoio: Bolsas no Brasil - Doutorado