Minnatullah, Md.AARADHNA2023-01-282023-01-282022M/PP/059/2020-21https://krishikosh.egranth.ac.in/handle/1/5810192862Sugarcane (Saccharum officinarum L.) is grown in more than 110 countries employing over seven million farming communities. It is an important agro-industrial crop of tropical and subtropical regions of India significantly contributing to revenue collection. The crop is affected by the majority of diseases among which wilt disease caused by Fusarium sacchari is one of the most prevalent in the Bihar region. During the survey conducted in different cane growing regions of Bihar, the highest disease incidence of 20.42% was observed in Manjhaulia followed by Gopalganj 14.09%, Lauriya 14.05%, Saugauli 11.56%, Harinagar 11.16% in severe form, Sidhawalia 9.08%, Narkatiyaganj 9.06%, Hasanpur 8.18% and Kalyanpur 5.97% in moderate form. To find out the level of resistance in sugarcane varieties, field as well as pot trials were carried out at SRI, RPCAU, Pusa in which thirty varieties were evaluated against Fusarium sacchari. In field condition, it was observed that 6 varieties (20.69%) were resistant, 15 varieties (51.72%) were moderately resistant, 5 varieties (17.24%) were moderately susceptible and 3 varieties (10.34%) were susceptible. The pot experiments revealed 6 varieties (20.69%) as resistant, 11 varieties (37.93%) as moderately resistant, 4 varieties (13.79%) as moderately susceptible and 8 varieties (31.03%) as susceptible. A significant loss noticed in different quantitative and qualitative attributes of sugarcane due to wilt.The reduction in germination% (6.14%-38.20%), settling mortality% (4.55%-41.24%), cane height (6.66%-27.83%), cane girth (2.67%- 45.16%), cane weight (6.40%-47.27%), brix % (4.04%-25.58%), sucrose % (6.96%-49.16%) and in purity % (3.04%-31.69%) was observed. Among the four chemical used for treatment, Thiophenate Methyl 70 WP @1gm/l was the best followed by Azoxystrobin 23% SC @ 1ml/l, Propiconazole 25 EC @ 1ml/l and the least effective Tebuconazole 25 g EC @ 1ml/l. Among the two bioagents usedfor treatment, Trichoderma harzianum @ 10 gm/l was more efficacious than Trichoderma asperellum @ 10 gm/l. The highest net return(Rs 123480/ha) was obtainedin Thiophenate Methyl 70WP @1gm/ltreated plots and the minimum net return of (Rs 15466/ha) was obtained from the plots treated withTrichoderma asperellum @ 10gm/l. The highest profit per rupees invested was obtained in the treatment with Thiophenate Methyl 70WP @1gm/l(1:1.09) while the lowest profit obtained per rupees was from the treatment Trichoderma asperellum @ 10gm/l(1:0.15) as per the calculated Cost-Benefit Ratio (CBR). Thus, it can be conculded that Thiophenate Methyl was the best treatment.EnglishThesis