After the fruits and vegetables are harvested, the value of fruits and vegetables is added in successive stages and remain in living phase. Losses due to postharvest disease may occur at any time during postharvest handling. The aim of postharvest management of diseases is to maximise the quality and storage value. The postharvest products are living and respiring materials, and from field to eating, several factors influence quality and there are many fungal and bacterial pathogens which affect them. The quality of these delicate products peaks at harvest when they are green and crisp, but during handling and storage their quality attributes may be deteriorated, resulting in products of inferior quality when they reach the consumers. Important genera of anamorphic postharvest pathogens include Penicillium, Aspergillus, Geotrichum, Botrytis, Fusarium, Alternaria, Colletotrichum, Dothiorella, Lasiodiplodia and Phomopsis. Some of these fungi also form ascomycete sexual stages. There should be integrated approaches to management the postharvest diseases to reduce the qualitative and quantitative loss of vegetables and fruits as fresh and during storage.

Among the fungal diseases, sheath blight, caused by multinucleate Rhizoctoniasolani Kuhn (teleomorph: Thanatephorus cucumeris Donk), a ubiquitous pathogen, is an important fungal disease of rice ranking only after blast and often rivalling it. The potential losses due to sheath blight alone in India has been up to 51.3%. In this study an attempt was made to investigate the antifungal efficacy of botanicals viz., neem (Azadirachtaindica), tulsi (Ocimum sanctum), garlic (Allium sativum), onion (Allium cepa), ginger (Zingiberofficinale) and various fungicides namely mancozeb, propiconazole, hexaconazole, carbendazim, and copper oxychlorideagainst Rhizoctoniasolani in vitro by poison food technique. R. solaniwas allowed to grow at 5%, 10% concentrations of botanicals and at 200, 500, 1000ppm of fungicides amended potato dextrose agar (PDA) medium. The effect of botanicals and fungicides on mycelial growth inhibition was recorded after 36, 48 and 72 post hrs inoculation (phi). It was observed that bulb extract of Allium sativumand rhizome extract of Zingiberofficinalesuppressed the mycelial growth (80.19 and 76.32, respectively) @ 10% followed by leaf extract of Azadirachtaindica(72.78 %) after 72 phi. Among the fungicides, the complete fungal growth inhibition was observed in propiconazole and carbendazim fungicides amended medium.

The present study aimed to investigate the biocontrol and growth enhancement potentials of Trichoderma spp., against R. solani. A total of 31 Trichoderma spp. were examined for their antagonistic potentials against R. solani in dual culture, effect of volatile and nonvolatile metabolites on the growth inhibition of test pathogen under in-vitro condition. The efficacy of Trichoderma spp. were further evaluated for controlling sheath blight and promoting rice growth under in-vivo conditions with different mode of applications. The results of in-vitro confrontation assay revealed that among the different Trichoderma spp. tested, T. harzianum (SVPRT-THLi06) and T. atroviride (SVPP-4) exhibited excellent biocontrol efficacy with 90.9% and 72.0% mycelial growth inhibition, respectively. The culture filtrate of T. harzianum (SVPRT-THLi6) at 50% was highly effective in reducing R. solani mycelial growth up to 95.9% and in case of volatile metabolites, maximum inhibition (72.5%) in mycelial growth of R. solani was recorded with T. harzianum isolate SVPP-8. A combined mode of application (soil treatment+ root dipping+ foliar spray) with T. harzianum (SVPRT-THLi06) was found most effective under greenhouse condition, which showed the least disease severity (12.4% vs control 49.6%) and disease incidence (27.1% vs control 96.4%). The present study revealed that T. harzianum (SVPRT-THLi06) has potential to control sheath blight disease as well as improve growth of rice crop. Therefore, in future it may be used as bio-based formulation for plant growth enhancement and managing sheath blight disease in rice cultivation and further may be applied in organic rice cultivation. Necrotrophic fungus, Rhizoctonia solani, Rice, Sheath blight, Trichoderma spp. Biocontrol and growth enhancement potential of Trichoderma spp. against Rhizoctonia solani causing sheath blight disease in rice

The Fusarium wilt of tomato (Lycopersicon esculentum Mill.) caused by Fusarium oxysporum f. sp. lycopersici (Sacc.) Snyder and Hansen is recognised as one of the most devastating disease and major yield limiting factor in tomato growing regions worldwide. For eco-friendly and sustainable management of the disease, 19 Trichoderma native isolates belonging to 3 species of the genus, T. harzianum, T. asperellum and T. virens were evaluated in vitro against the pathogen using dual culture method. Out of 19 isolates, 8 isolates showed mycoparasitism, 8 isolates showed antibiosis and remaining showed lysis. Microscopic observations of Fusarium oxysporum f. sp. lycopersici (FOL) growth in dual cultures revealed that growth inhibition occurred just before near to contact with the antagonist. All T. harzianum isolates tested exhibited coiling around the hyphae of FOL. Isolates of T. harzianum, showed good coiling and growth inhibition of the pathogen. The T. harzianum strains did not differ in coiling pattern and gave somewhat equal coiling performances. Strains of T. asperellum, showed coiling but the coiling pattern of all these strains was different. Only one strain of T. virens showed coiling out of 2 strains. Among them T. harzianum (SVPUTh91) showed the best performance in vitro as biological control agent against FOL followed by T. asperellum and T. virens, resulting in 83, 73 and 65% reduction in colony growth, respectively.

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