ABSTRACT
Leaf blight of the medicinal plants (Piper longum, Tylophora indica and Hibiscus subdariffa) is one of the most significant diseases that severely damage these crops throughout the year in West Bengal .So, management of this disease is essential at now. A few chemical fungicides and trichoderma isolates were tested under in vitro against the disease-associated pathogens in order to identify efficient chemical fungicides and bio agents.It was found that the trichoderma isolates T-2 and T-3 were effective against Colletotrichum gloeosporioides, whereas the isolates T-1 and T-2 were efficient in inhibiting the growth of the test pathogen better against Fusarium sp. and Sclerotium rolfsii.With a higher percentage of inhibition (77.60%), copper oxychloride was the most effective fungicide against Fusarium sp. Conversely, carbendazim and dithane m-45 were more effective against Sclerotium rolfsii and Colletotrichum gloeosporioides, showing 78.33% and 77.93% of inhibition, respectively, and less effective against Fusarium sp at higher concentrations (400 ppm). To determine whether or not these chemical fungicides and trichoderma isolates are effective under in vivo, they will be tested in the field against the corresponding pathogens associated with the disease.
ABSTRACT
Twelve isolates of Trichoderma (six of T. harzianum, five of T. viride, one of T. virens), which reduced variably the incidence of collar rot disease caused in peanut by Aspergillus niger Van Tieghem, were evaluated for their potential to produce lytic enzymes during in vitro antagonism. T. viride 60 inhibited highest (86.2%) growth of test fungus followed by T. harzianum 2J (80.4%) at 6 days after inoculation (DAI) on PDA media. The specific activities of chitinase, -1,3-glucanase and protease were 11, 3.46 and 9 folds higher in T6 antagonist (T. viride 60 and A. niger interactions) followed by 8.72, 2.85 and 9 folds in T8 antagonist (T. harzianum 2J and A. niger interactions), respectively, compared to the activity produced by control petri plate T13 (A. niger alone) at 6 DAI. Activity of these lytic enzymes induced in antagonists' plates comprises the growth of Trichoderma isolates. However, cellulase and poly galacturonase were found least amount in these antagonists treatment. A significant positive correlation (p=0.01) between percentage growth inhibition of test fungus and lytic enzymes - (chitinase, -1,3-glucanase and protease) in the culture medium of antagonist treatment established a relationship to inhibit growth of fungal pathogen by increasing the levels of these enzymes. Among the Trichoderma isolates, T. viride 60 was found best strain to be used in biological control of plant pathogen A. niger.
ABSTRACT
Twelve isolates of Trichoderma (six of T. harzianum, five of T. viride, one of T. virens), which reduced variably the incidence of collar rot disease caused in peanut by Aspergillus niger Van Tieghem, were evaluated for their potential to produce lytic enzymes during in vitro antagonism. T. viride 60 inhibited highest (86.2%) growth of test fungus followed by T. harzianum 2J (80.4%) at 6 days after inoculation (DAI) on PDA media. The specific activities of chitinase, â-1,3-glucanase and protease were 11, 3.46 and 9 folds higher in T6 antagonist (T. viride 60 and A. niger interactions) followed by 8.72, 2.85 and 9 folds in T8 antagonist (T. harzianum 2J and A. niger interactions), respectively, compared to the activity produced by control petri plate T13 (A. niger alone) at 6 DAI. Activity of these lytic enzymes induced in antagonists' plates comprises the growth of Trichoderma isolates. However, cellulase and poly galacturonase were found least amount in these antagonists treatment. A significant positive correlation (p=0.01) between percentage growth inhibition of test fungus and lytic enzymes - (chitinase, â-1,3-glucanase and protease) in the culture medium of antagonist treatment established a relationship to inhibit growth of fungal pathogen by increasing the levels of these enzymes. Among the Trichoderma isolates, T. viride 60 was found best strain to be used in biological control of plant pathogen A. niger.