Ambient air contains high amounts of potentially genotoxic and carcinogenic aromatic hydrocarbons (AH) that originate from the petroleum related activities and coal refining processes. The potential of phyllosphere organisms to oxidize these compounds into nontoxic forms has been investigated in some recent studies. This study was carried out to investigate the presence of aromatic hydrocarbon degrading fungi in the phyllosphere of Ixora sp., Amaranth sp., Hibiscus sp. and Ervatamia sp. which are common on roadsides close to the oil refinery at Sapugaskanda and in several urban areas having high level of vehicular emission. Their ability to degrade the AHs phenanthrene, naphthalene, xylene and toluene was investigated.

Aims: Meloidogyne incognita adversely affects numerous crop plants worldwide. Therefore, the modern world has been moving towards biocontrol methods to prevent nematode attacks. This study was aimed to (i) investigate the potential use of Trichoderma harzianum NFCF160 and T. virens Isf-77 in managing M. incognita in soil and (ii) identify trapping mechanisms employed by both Trichoderma strains to suppress M. incognita. Methodology and results: Three weeks old, Basella alba L. plants were subjected to five different treatments. The above and below ground growth parameters and the galling indices of these plants were measured every four weeks for three sampling times. Trapping mechanisms employed by Trichoderma strains were examined following plate assays. Plants treated with T. harzianum NFCF160 and T. virens Isf-77 had significantly higher values for the total number of leaves (34 ± 2.84) and (27 ± 2.61), fresh weight of the shoot (81 ± 9.51 g) and (91 ± 9.70 g), dry weight of the shoot (71 ± 5.24 g) and (62 ± 5.81 g), respectively eight weeks after inoculation of M. incognita. Significantly low galling indices (2 and 2) were recorded in B. alba treated with Trichoderma strains. Both Trichoderma strains exhibited various nematodetrapping mechanisms, such as non-constricting rings and adhesive spores. Conclusion, significance and impact of study: This investigation highlighted the potential of both Trichoderma strains as biocontrol agents to control M. incognita effect in sustainable agriculture.