Evaluation of Trichoderma harzianum, Bacillus subtilis and Aspergillus species efficacy in controlling Pythium ultimum associated with apple seedlings decline in nurseries and their growth promotion effect

Abstract Background Apple decline diseases, responsible for seedlings root and collar rot in nurseries, are an important disease. Different fungal bacterial antagonists were evaluated to control Pythium ultimum associated with this serious disease using vitro vivo greenhouse assays. Results The test of ten Aspergillus spp. Trichoderma harzianum isolates showed their efficacy reduce the radial growth P. . isolates, A. niger A10, candidus A5, T. Tr9 Tr10, most effective a high inhibition percent that exceeded 50%. four strain Bacillus subtilis (B) combination two (A5 A10) gave best result decrease browning index by 55.55%. also all tested combinations on sanitary state inoculated plants except between (Tr10) B. (B). treatments, (B), significantly improved height 173.19 191.3%, respectively. Regarding apple weight, (A10) was only treatment increased parameter 363.17%. Conclusions Tr10 exhibited highest value A10 A5 reducing severity index. However, (Tr10), revealed be able stimulate growth.