Spore dispersal of leaf blotch pathogens of wheat (Mycosphaerella graminicola and Septoria tritici)

CORDO, C; SIMÓN, MR; PERELLÓ, A.; ALIPPI, H.

Septoria and Stagonospora Diseases of Cereals: A compilation of Global Research

van Ginkel, Krupinsky Ed

Lugar: D.F. CIMMYT; Año: 1999; p. 98 - 101

Abstract The spatial and temporal patterns of discharge and dissemination of air-borne Mycosphaerella graminicola spores and of Septoria tritici spores through rain splash were studied. Spore traps were used to monitor both ascospores and pycnidiospores when the wheat crop was in the vegetative and debris states. Relationships between distance from a point source and weather variables such as rainfall, relative humidity, and air temperature were analyzed. The release of pycnidiospores was favored by rainfall, as was explained through the multiple regression model (18% of the variation). Air dispersal of ascospores and splash dispersal of pycnidiospores were significantly influenced by each of the weather variables. The number of air-borne ascospores increased in association with rainfall. The multiple regression model explained 59% of the variation. The correlation analysis showed significant association with temperature, humidity, and rainfall; the regression coefficients of the climatic variables were significant. The effect of different distances from the inoculum source on the density of rain-splashed pycnidiospores and wind-borne ascospores was not significant. Pycnidiospores were the omnipresent inoculum in the cereal-producing area during the observed period. Thus this inoculum poses a risk to crop production and may be important to the epidemiology of septoria diseases under the climatic conditions in the wheat-producing areas of Argentina.