First Report of Ashy stem blight caused by Macrophomina phaseolina on Aeonium canariense in Egypt

Abstract

Cactus plants Aeonium canariense L. (Webb & Berthelot) showing symptomsof ashy stem blight disease, collected from some ornamental nurseries,resulted in isolation of the causal organism Macrophomina phaseolina(Tassi) Goid. The in vitro optimum temperature for fungal growthwas recorded at 300C. Topsin-M showed high inhibitory effect on thefungal growth in vitro. Complete growth inhibition of M. phaseolinawas observed at concentration of 4ppm, while the growth of the bioagentTrichoderma harzianum inhibited completely at 10ppm. Antagonisticability of T. harzianum against M. phaseolina increased graduallyin the presence of the fungicide in growth medium to cause completereduction in pathogenic fungal growth at 2ppm of Topsin-M. Undergreenhouse conditions application of integrated treatment of T. harzianumand Topsin-M had superior effect for suppressing the disease incidenceof cactus plants Aeonium canariense L. by 100% comparing with eachindividual treatment of either fungicide (86.67%) or the bioagent(73.33%). It could be suggested that application of biological andfungicidal integrated treatment might be used as successful controlmeasure for ashy stem blight of cactus plants Aeonium canarienseL. cactus plants Aeonium canariense L. To the best of our knowledgethis is the first report for M. phaseolina caused infection to cactusA. canariense in Egypt.