Singh, S.N.Sameera, Gedela Venkata Hima2024-06-282024-06-282023M/PP/165/2021-2022https://krishikosh.egranth.ac.in/handle/1/5810211141One of the most significant cash crops in the world, Sugarcane (Saccharum officinarum L.) is grown in more than 80 different nations for the production of white sugar, bio-ethanol, jaggery and other by-products. India produces 20% of the world's sugarcane, and the largest producer of sugar. In Bihar as per recent reports (Directorate of Economics & Statistics 2020-2021) sugarcane covers an area of 0.22 mha having cane production of 10.71mt and productivity of 48.92 t/ha. Based on the survey it was found that the maximum red rot incidence was observed in the sugarcane cultivar Co 0238 (45%) dominating over all the varieties growing in both the districts viz. Samastipur and Gopalganj. covering more than 70 per cent sugarcane area. Cultivars BO 91 and Rajendra Ganna- 1 were found free from the infection of red rot. Out of the two districts, Samastipur district was more affected with red rot disease with mean disease incidence of 18.18 per cent as compared to Gopalganj district (12.26%). Seven isolates were obtained from the collected diseased specimen where the colour of the mycelium of all the isolates varied as whitish grey, greyish white, and pinkish white. The texture of the mycelium was either fluffy, abundant, aerial, scanty raised mycelium. The shape of the conidia was observed as falcate. The average length of the conidia ranged from 21.32µm to 27.37 µm and the average width varied from 4.10 µm to 4.39 µm. Four bio control agents were tested for their antagonistic potential against Colletototrichum falcatum in vitro as well as under field conditions where Bacillus subtilis showed maximum inhibition of test fungus mycelium (69.4%) in bacterial bio control agents whereas in fungal bio control agents, Trichoderma harzianum showed maximum mycelial inhibition (63.9%) and maximum bud germination was recorded in plots treated with Trichoderma harzianum (35.5%), minimum settling mortality (5.3%) and minimum red rot incidence (20.3%) as compared to control (29.0%), (11.3%), (38.1%) respectively. Four SAR molecules were tested for their antifungal properties against Colletotrichum falcatum in vitro and under field conditions, Salicylic acid showed 100 per cent inhibition of radial growth of mycelium at all three concentrations and Potassium silicate showed 100 per cent inhibition of mycelial growth at 1500 ppm and 2000 ppm concentrations and maximum bud germination was recorded in plots treated with Potassium silicate(PSi) (36.3%), minimum settling mortality (4.9%) and minimum red rot incidence (25.5%) as compared to control (27.0%), (12.4%), (39.8%) respectively. Management of red rot disease of sugarcane by integration of bio control agents and fungicides revealed that treatment T7 (Sett treatment with Carbendazim 50 WP @ 0.1% + soil drenching with T.harzianum @ 0.6% + three foliar application with fungicide Azoxystrobin 11% + Tebuconazole 18.3% @ 0.1%) and treatment T8 (Sett treatment with Carbendazim 50 WP @ 0.1% + soil drenching with T.harzianum @ 0.6% + three foliar application with fungicide Thiophanate methyl 70 WP @ 0.1%) have the potential to control the disease and ultimately enhanced the performance of yield attributing characters, yield and quality such as brix, pol and purity per cent. This finding established the fact that integration of bio control agents and fungicides can be used for effective management of the red rot disease of sugarcane. SAR molecules may also be an alternative of fungicides.EnglishThesis