Effect of Some Biological Agents on Fungi Isolated from Roots and Soil around it of Cupressus spp. Trees

Abstract

Al-Ameri, H.A. 2024. Effect of Some Biological Agents on Fungi Isolated from Roots and Soil around it of Cupressus spp. Trees. Arab Journal of Plant Protection, 42(2): 224-228. https://doi.org/10.22268/AJPP-001233 Relative occurrence of fungi associated with six root and six soil samples from the rhizosphere of Cupressus/cypruss trees with root rot, leaf blight or wilt symptoms were investigated. Results of the root samples (average of six samples) showed that the relative occurrence of Fusarium culmorum was the highest (36.81%), followed by F. solani (29.7%), Alternaria. alternate (14.19%), F. oxysporum (10.67%), R. solani (5.51%), Pythium spp. (1.69%), Helminthosporium spp. (0.85%), Bipolaris spp. (0.24%) and Stemphilium herbarum (0.18%). However, the average occurrence in the six soil rhizosphere samples was the highest for F. solani (41.28%), followed by R. solani (19.76%), F. culmorum (16.5%), F. oxysporum (8.77%), Bipolaris spp. (6.17%), A. alternata (3.99%), Pythium spp. (2.70%), Stemphylium herbarum (0.60%), and Helminthosporium spp. (0.27%). Results also showed that Trichoderma harzianum had a high antagonistic efficiency against the three studied fungi isolated from cypress tree roots and the surrounding soil, namely F. culmorum, F. solani and Helminthosporium spp. Based on 1-5 scale, the inhibition level was 1.0 against each of the pathogenic fungi F. culmorum, F. solani, and 2.0 against Helminthosporium spp. The results also showed that the use of B. subitlis as bacterial bio-control agent led to a significant inhibition of the growth of the three isolated fungi, F. culmorum, F. solani and Helminthosporium spp. cultured on PDA medium. Keywords: Bio-control agents, F. culmorum, F. solani, Cypress trees.