Browsing by Author "Sarma, T.C."

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    Antifungal activity of some plant extracts against ganoderma lucidum (curtis ex.fr.) karst., causing basal stem rot disease in arecanut
    (2014) Chakrabarty, R.; Acharya, G.C.; Sarma, T.C.
    Basal stem rot disease caused by the fungus, Ganoderma lucidum (Curtis Ex. Fr.) Karst, is the most dreaded disease of arecanut in Assam. The experiment was carried out to test the antifungal activity of aqueous extract of thirty locally available plant species against the test fungus. Pure culture of Ganoderma sp. was isolated from fruiting body of infected arecanut palm. Among the plant species tested, Allium sativum corm extract exerted maximum inhibition with 90.89, 100 and 100 per cent inhibition over control at 5, 10 and 20 per cent conc. respectively, followed by extract of Solanum nigrum with 77.00. 84.11 and 100 per cent inhibition over control at 5, 10 and 20 per cent conc. respectively after 144h of incubation. Leaf extract of Clerodendron infortunatum, Bidens pilosa, Leucas aspera, Spilanthes paniculata, Lawsonia inermis and Cinnamomum verum showed strong inhibitory effect at 20 per cent conc. with 84.00, 83.88, 79.22, 77.22, 76.11 and 72.78 per cent inhibition over control respectively.
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    Effect of fungicides, Trichoderma and plant extracts on mycelial growth of Thielaviopsis paradoxa, under in vitro condition
    (2013) Chakrabarty, R.; Acharya, G.C.; Sarma, T.C.
    Stem bleeding disease caused by Thielaviopsis paradoxa is one of the major diseases of coconut and is prevalent in almost all the coconut growing countries. The present study was carried out to test the efficacy of antagonist, fungicides and plant extracts in inhibiting the pathogen, under in vitro condition. Thielaviopsis was isolated from young lesion of affected coconut palm of CPCRI, RC, Kahikuchi, Guwahati. Among the three species of Trichoderma tested so far, T. viride was found to be the most effective with 61.62% inhibition followed by T. harzianum and T. virens with 60.80 and 59.49 per cent inhibition, respectively, over control after 96h of incubation period. The fungicides, Calixin (Tridemorph 80EC) @ 0.3% showed 100 per cent inhibition over control whereas Ridomil MZ-72, Blitox-50 and Bavistin showed 92.00, 91.55 and 91.44 per cent inhibition over control after 144h of incubation, respectively, Among the forty five plant extracts tested, the aqueous extract (10%) of Allium sativum, exerted 100 per cent inhibition of the pathogen over control after 48h, 72h and 96h of incubation compared to other extracts.
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    Evaluation of substrates for multiplication of bio-agent, Trichoderma viride
    (2014-06) Chakrabarty, R.; Acharya, G.C.; Sarma, T.C.
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    Management of basal stem rot of arecanut (Areca catechu L.) under Assam condition
    (2013) Chakrabarty, R.; Acharya, G.C.; Sarma, T.C.
    Among the various factors causing considerable loss in production of arecanut in the state, basal stem rot disease caused by the fungus Ganoderma lucidum (Curtis Ex. Fr.) Karst, is the most dreaded. Survey indicated that in different parts of Assam, disease incidence of 0.1-65% was observed. Studies were undertaken to develop an effective management practices both in vitro and in vivo against the disease at CPCRI Research Centre, Kahikuchi. Among the fungicides tried in vitro, calixin (Tridemorph, 80EC) @ 0.3% completely inhibited the growth of the fungus, followed by bavistin (Carbendazin, 50WP) @ 0.3% with 91.33% inhibition over control after 144 hrs of incubation. Dual culture study carried out with three different species of Trichoderma revealed that T. viride was most effective, followed by T. harzianum and T. virens with 66.55, 63.99 and 62.12 per cent inhibition over control after 96 hrs of incubation. Based on the in vitro study, a field trial was undertaken to develop locationspecific, farmers’-friendly management practices to reduce the severity and spread of the disease. The treatment, T1 - soil drenching with calixin (0.3%) @ 10 l/palm at quarterly interval was most effective followed by T4 - application of neem cake (2 kg/palm/ year) fortified with T.viride (100g/palm/year) in controlling the disease.