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

Abstract

Cactus plants Aeonium canariense L. (Webb & Berthelot) showing symptoms of 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 growth was recorded at 30 0 C. Topsin-M showed high inhibitory effect on the fungal growth in vitro. Complete growth inhibition of M. phaseolina was observed at concentration of 4ppm, while the growth of the bioagent Trichoderma harzianum inhibited completely at 10ppm. Antagonistic ability of T. harzianum against M. phaseolina increased gradually in the presence of the fungicide in growth medium to cause complete reduction in pathogenic fungal growth at 2ppm of Topsin-M. Under greenhouse conditions application of integrated treatment of T. harzianum and Topsin-M had superior effect for suppressing the disease incidence of cactus plants Aeonium canariense L . by 100% comparing with each individual treatment of either fungicide (86.67%) or the bioagent (73.33%). It could be suggested that application of biological and fungicidal integrated treatment might be used as successful control measure for ashy stem blight of cactus plants Aeonium canariense L . cactus plants Aeonium canariense L. To the best of our knowledge this is the first report for M. phaseolina caused infection to cactus A. canariense in Egypt.