Spread of endosepsis in Calimyrna fig orchards

• Published in: Phytopathology Vol. 88; no. 7; pp. 637 - 647
• Main Authors: Michailides, T.J. (University of California, Parlier.), Morgan, D.P
• Format: Journal Article
• Language: English
• Published: St. Paul, MN American Phytopathological Society 01-07-1998
• Subjects: AGENT PATHOGENE; Biological and medical sciences; BLASTOPHAGA PSENES; CAPRIFICATION; CAPRIFIGS; DISEASE MODELS; DISEASE TRANSMISSION; DISEASE VECTORS; ENFERMEDADES FUNGOSAS; EQUATIONS; ESPACEMENT; ESPACIAMIENTO; FICUS CARICA; Fundamental and applied biological sciences. Psychology; FUNGAL DISEASES; Fungal plant pathogens; GIBBERELLA FUJIKUROI; HUERTO FRUTAL; HYMENOPTERA; MALADIE FONGIQUE; MATEMATICAS; MATHEMATICAL MODELS; MATHEMATICS; MATHEMATIQUE; MODELE; MODELE MATHEMATIQUE; MODELOS; MODELOS MATEMATICOS; ORCHARDS; ORGANISMOS PATOGENOS; PATHOGENICITY; PATHOGENS; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; PATOGENICIDAD; Phytopathology. Animal pests. Plant and forest protection; PLANT PRODUCTION; POLINIZADORES; POLLINATORS; POLLINISATEUR; POUVOIR PATHOGENE; PRODUCCION VEGETAL; PRODUCTION VEGETALE; ROW SPACING; SINTOMAS; SPACING; SYMPTOME; SYMPTOMS; TRANSMISION DE ENFERMEDADES; TRANSMISSION DES MALADIES; VECTEUR DE MALADIE; VECTORES; VECTORS; VERGER; California; United States; North America; America; Disease development; Symbionte; Insecta; Agaonidae; Moraceae; Epidemiology; Ficus carica; Field experiment; Pollination; Fungi; Orchard; Arthropoda; Chalcidoidea; Dicotyledones; Dissemination; Angiospermae; Fusarium; Spermatophyta; Fruit tree; Fungi Imperfecti; Hymenoptera; Invertebrata; Vector; Thallophyta
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/PHYTO.1998.88.7.637

Pollination of the edible fig (Ficus carica cv. Calimyrna) is mediated by a small symbiotic wasp, Blastophaga psenes, that inhabits the syconium cavity of the spring crop of fig pollinator trees (caprifigs). These fig wasps also carry propagules, mainly of Fusarium verticillioides (formerly F. moniliforme) and other Fusarium spp., which cause endosepsis, from pollinator figs to the edible Calimyrna figs in California. Spread of endosepsis was studied in one experimental and up to four commercial Calimyrna fig orchards from 1989 through 1995. The incidence of endosepsis in fruit collected from the tree canopy at either 2.0 m (low) or 2.0 m (high) height, from the north and south of the tree canopy, and from the outer (direct sunlight) and inner (shaded) canopy were similar. More wasps were captured in fig trees located 3.5 to 10 m east or west of the source than in trees 48 to 63 m from the source. In addition, significantly more wasps entered the syconia of trees closest (9 to 12.7 m) to the source than the syconia of the second or third trees (18 to 38.2 m) from the source. Endosepsis decreased with distance from the source, decreasing faster to the south than in other directions from the source. In addition, the disease-vectoring wasps decreased with increased distance from the source, which also described the disease spread from the contamination source for most directions, with a sharper decline south of the source. A 3-year study in three commercial Calimyrna orchards showed there is no secondary spread of fig endosepsis in the field. Although endosepsis can complete as many cycles (three to four) as its vector in fig pollinator trees, in Calimyrna figs it is considered a monocyclic disease Because fig wasp pollinators prefer to stay close to the contamination source when receptive Calimyrna figs are available in close proximity, only disease sources (caprifigs trees) found among Calimyrna trees or at a distance less than 50 m from the borders of Calimyrna or...