Bireswar Sinha

In vitro Studies on Efficacy of Agro-Chemicals against Collar Rot of Tomato Caused by Sclerotium rolfsii Saccin Manipur

Sclerotium rolfsii is a soil inhabitant, nontarget, polyphagous, and a ubiquitous facultative parasite. It is widely distributed in the world and has host range of 500 plant species. It was first observed by Peter Henry Rolfs in the year 1892 on tomato plants with 70% losses. The hyphae grew upward on the surface of the infected plant covered with a cottony, white mass of mycelium, scattered inside and outside of infected stem nearby the soil surface. Its major survival mechanism is through sclerotial bodies which can persist in temperature range of -10 0 C to 50 0 C (kator et al., 2015). Its geographic distribution, profuse mycelial growth, persistent sclerotia and large number of hosts attacked by it indicate that, economic losses are substantial every year due to infection of S. rolfsii. Keeping in view the significance of economic crops, the present findings were carried out to understand the effect of various agro-chemicals against S. rolfsii.

In vitro Studies on Efficacy of Some Plant Extracts and Biocontrol Agents against Lasiodiplodia theobromae and Lasiodiplodia pseudotheobromae

ISSN: 2319-7706 Volume 7 Number 07 (2018) Journal homepage: http://www.ijcmas.com Stem-end rot of mango caused by Lasiodiplodia theobromae and Lasiodiplodia pseudotheobromae is a major post-harvest problem in Manipur and reduces yield. An experiment on antifungal efficacy of three plant extracts viz., Garlic (Allium sativum), Neem (Azadirachta indica) and Ginger (Zingiber officinale) was done through poisoned food technique by taking three concentrations in in vitro conditions against the pathogens and eight Trichoderma isolates viz., T. ovalisporum (KU904456), T. koningiopsis (KU904460), T. harzianum (KU904458), T. atroviride (KU933472), T. harzianum (KU933474), T. asperellum (KU933475), T. asperellum KU933476) and T. hypocrea (KX0113223) were evaluated against the pathogens through production of non-volatile (Dennis and Webster, 1971a) and volatile Dennis and Webster, 1971b) compounds. The results revealed that among plant extracts, the highest inhibition for Lasiodiplodia theobromae was shown by garlic at 1.25, 2.5 and 5 per cent of 100 per cent and for Lasiodiplodia pseudotheobromae, the highest inhibition was showed by garlic at 5 per cent of 81.17 per cent. Effect of volatile compounds produced by Trichoderma spp against Lasiodiplodia theobromae showed maximum percentage inhibition with isolate T. asperellum (KU933476) of 95.24 per cent and T. hypocrea (KX0113223) least by 68.52 per cent. Effect of volatile compounds produced by Trichoderma spp against Lasiodiplodia pseudotheobromae showed maximum percentage inhibition with isolate T. ovalisporum (KU904456) of 12.39 per cent and no inhibition was observed by T. asperellum (KU933475), T. atroviride (KU933472), T. harzianum (KU933474), T. harzianum (KU933458), T.koningiopsis (KU904460), and T. hypocrea (KX0113223) against the pathogen. Effect on non-volatile compounds produced by Trichoderma spp. at two different concentrations viz., 7.5% (v/v) and 15% (v/v) against Lasiodiplodia theobromae showed 42.36 to 82.40 per cent at 7.5% v/v concentration and 53.70 to 100.00 per cent at 15% v/v concentration, In Lasiodiplodia pseudotheobromae, results showed 3.59 to 56.31 per cent at 7.5% v/v concentration and 44.47 to 100.00 per cent at 15% v/v concentration. Present study suggests that Garlic and Trichoderma spp. could be tried for the eco-friendly management of the diseases. K e y w o r d s Mango, Postharvest, Plant extracts, Trichoderma spp Accepted: 06 June 2018 Available Online: 10 July 2018 Article Info Int.J.Curr.Microbiol.App.Sci (2018) 7(7): 448-457

Antagonistic Potential and Molecular Characterization of Trichoderma spp. against Rhizoctonia solani Infecting Ghost Pepper in Manipur, India

Bhut jolokia (Capsicum chinense Jacq.) is one of the world’s hottest chilli entered in the Guinness book of world record (2006). Many pest and diseases ruined Bhut jolokia and among them damping-off disease of seedling as well root and stem rot in young transplants caused by Rhizoctonia solani is one of the important limiting factor in cultivation and production (Ngullie and Daiho, 2013). Even though numbers of crop plant diseases are managed by chemicals it causes degradation of beneficial microbes in the soil, physiological resistance in the pathogen and pollution. To keep away from such problems and combat of plant pathogens, use of biocontrol agents becomes necessary.

Native Trichoderma spp for the Management of Stem Rot of Groundnut Caused by Sclerotium rolfsii Sacc in Manipur

Groundnut (Arachis hypogeae L.) is an important oilseed crop of tropical and subtropical region of the world. It is native of South America and belongs to annual legume group. Groundnut kernel is rich source of energy because of its oil (44-48%) and protein content (25-36%) than meat, about two and a half times than in eggs, and far more than any other vegetable food except soybean and yeast. In India it is grown mainly in Gujarat, Maharashtra, Andhra Pradesh, Uttar Pradesh, Tamil Nadu, Rajasthan, Karnataka and Madhya Pradesh. The crop is known to be attacked by number of fungal, bacterial and viral diseases. The literature reveals that the yield losses caused by major fungal disease like leaf spot, rust and soil borne diseases like stem rot, root rot, collar rot and pod rot singly or in combination as high as 15-70% during both kharif and rabi-summer season (Subramanyam et al., 1984).The stem rot of groundnut is caused by pathogen (Sclerotium rolfsii Sacc.) is a soil inhibitant, polyphagous, facultative fungal parasite. It is documented that the fungal has host range of 500 plant species including several cultivated field and vegetables crops and many others (Aycock 1966).The fungus survived in the soil for many years by producing sclerotial bodies International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 10 (2017) pp. 1343-1351 Journal homepage: http://www.ijcmas.com