In vitro and in vivo evaluation of different botanicals and to know the efficacy of chemical fungicides against the pathogen (Rhizoctonia solani) on Swarna variety of rice crop.
The antifungal effect of 13 plant extracts viz., Aloe barbadensis, Cymbopogon citrates, Datura inoxia, Datura stramonium, Hibiscus rosa sinensis, Ipomea carnea, Nerium indica, Nyctanthes arbor tristis, Parthenium hysterophorus, Pterocarpus santalinus, Saraca asoca, Syzygium cumini, Vinca rosea, were evaluated by poisoned food technique under in-vitro condition against Rhizoctonia solani Kuhn, the causal organism of sheath blight of rice (Oryzae sativa). Among all the plants screened, most of the plants have recorded significant antifungal effect against Rhizoctonia solani. and only one plant namely, Saraca asoca have completely inhibited the growth of the pathogen. The effective concentration inhibiting the growth of mycelial formation of the pathogen by the plant extract was at 100% concentration. And it was also observed that the efficacy of mycelial formation was at varying degree depending upon the plant extract whereas no sclerotia was formed in most of the plant extract. Under In vivo condition, the extract of Datura inoxia, Datura stramonium, Ipomea carnea and Saraca asoca had completely checks the lesion length and extracts of Nerium indica, Aloe barbadensis, Vinca rosea and Syzygium cumini had checks more than two third development of lesion length. While the extract of Cymbopogon flaxuosus, Hibiscus rosa sinensis, Nyctanthes arbor tristis, Parthenium hysterophorus, and Pterocarpus santalinus showed least percent reduction in lesion length over control. Six fungicides were assessed in-vivo condition to find out the most effective inhibitor for growth of sheath blight pathogen. Amongst the fungicides inhibited the pathogens growth, it was found that all fungicidal treatment were significantly superior in reducing the lesion length over non treated control. Minimum lesion length was recorded in foliar application of Amistar25 SC (6.85 cm) followed by Nativo 75 WG (7.96 cm) and Bavistin 50 WP (8.19 cm). They are statistically at par with each other. Least reduction in lesion length (42.51 cm) was recorded in Tilt 25 EC.