Clethodim herbicide (Cle) and three Trichoderma strains (Tri) were applied either alone or in combination (Cle + Tri) for controlling weeds, root knot nematodes (Meloidogyne arenaria) and Rhizoctonia root rot disease (Rhizoctonia solani) as well as for evaluating their effects on total microbial count in the rhizosphere and the number of Rhizobium nodules on roots in two faba bean cultivars cultivated in naturally heavily infested fields. The evaluated characters were very similar for the two tested cultivars (Nubariya 1 and Sakha 3). Treatment with Cle alone highly reduced the fresh and dry matter of tested weeds (Amaranthus viridis, Cynodon dactylon and Cenchrus ciliaris), followed by Cle + Tri and Tri alone. Cle + Tri highly reduced nematode parameters viz. numbers of J2 in soil or roots, females, eggs, galls and egg-masses when compared with each treatment alone. Tri alone caused a great decrease in Rhizoctonia root rot infection, followed by Cle + Tri and Cle alone. Total microbial count and Rhizobium nodules were affected only with Cle treatment. Plant growth parameters (shoot length, shoot fresh and dry weight and numbers of branches and leaves) and yield parameters (fresh pod and dry weight, seed number per pod, seed weight and ash pod weight of plant) were greatly improved for Cle + Tri treatments when compared with either Tri or Cle alone.
A representative group of hydrophilic fungi from the genus Trichoderma isolated from lignocellulose composts with varying degrees of maturity was analyzed for their ability to biodegrade a harmful anthraquinone dye, i.e. Remazol Brilliant Blue R (RBBR). In RBBR-containing post-culture liquids, there were determined the degree of RBBR decolorization, horseradish peroxidase-like, superoxide dismutase-like, and xylanase activities, and the concentrations of low-molecular phenolic compounds. The study results demonstrated that Trichoderma asperellum, T. harzianum, and T. lixii strains isolated from compost containing larger amounts of easily available lignocellulose fractions, i.e. grasses, exhibit higher RBBR decolorization effi ciency ranging from 0.3 to 62% than T. citrinoviride strains isolated from compost II, which contained greater quantities of hardly degradable lignocellulose. The decolorization of remazol blue R by the investigated Trichoderma strains intensified signifi cantly with the increase in peroxidase activity and it was correlated with a decline in the content of low-molecular phenolic compounds. The dynamics of changes in the horseradish peroxidase-like, superoxide dismutase, and xylanase activities in the aqueous post-culture liquids of the investigated fungal strains depended largely on the duration of the culture. Given their ability to adapt to water environments, e.g. wastewater, and to decolorize and detoxify the RBBR anthraquinone dye, Trichoderma fungi can be used for bioremediation of such environments.