Spatial and temporal spread of Fusarium wilt of muskmelon caused by Fusarium oxysporum f. sp. melonis

The spatial and temporal development of Fusarium wilt of muskmelon caused by Fusarium oxysporum f. sp. melonis was studied in a naturally infested field. The study revealed that during the early stages of disease development, infected plants were randomly scattered over the entire field. But, at later stages, newly diseased plants were observed adjacent to previously diseased ones forming distinct foci of disease patches in the field, which enlarged along the rows. Progression curve of the disease followed a logistic pattern indicating effectively polycyclic behaviour of the pathogen and dissemination of inoculum occurred via roots. Spatial variogram characterized the degree of spatial dependency and range of pathogen dissemination indicating that pathogen could spread upto three plants on either side of infected plant. Intermingling roots appeared to facilitate the infection process.