Influence of nitrogen levels and non-chemical management strategies on sheath rot (Sclerotium rolfsii) of napier hybrid

Napier hybrid is high yielding and perennial fodder crop admired by most of the dairy farmers. Sheath rot caused by Sclerotium rolfsii has been noticed on napier hybrid during past few years in Punjab state, India. Hence, to find out best management options and optimum nitrogen rate, experiments were conducted in 2018 and 2019 to determine the effect of different nitrogen levels (0, 50, 75 and 100 kg N ha(-1)), plant extracts and organic inputs on sheath rot development. In vitro studies showed that extracts of Aegle marmelos (92%), Nicotiana tabacum (89%), Murraya koenigii (86%) and organic inputs like panchgavya (100%), vermiwash (97%) and compost tea (96%) provided highest mycelial growth inhibition. In field trials, panchgavya provided least area under disease progress curve (AUDPC) values (689 and 492) and more than 80% reduction in sheath rot severity followed by A. marmelos and vermiwash with significant enhancement in green fodder yield by 42 and 46% in 2018 and 2019, respectively. The application of nitrogen rate 75 kg N ha(-1) decreased the disease severity by 37% with 47% enhancement of green fodder yield in napier hybrid.

Automated summary

Napier hybrid is a favored high-yielding perennial fodder crop among dairy farmers. Due to the sheath rot caused by Sclerotium rolfsii on napier hybrid in Punjab, India, experiments were conducted to study the effect of different nitrogen levels, plant extracts, and organic inputs on disease management. Results showed that plant extracts such as Aegle marmelos, Nicotiana tabacum, Murraya koenigii, and organic inputs like panchgavya, vermiwash, and compost tea had high mycelial growth inhibition on the pathogen, with panchgavya showing the best results in field trials in terms of disease control and fodder yield increase.