Abstract

Introduction: Niger (Guizotia abyssinica L.) is a traditional minor oilseed crop predominantly cultivated in tribal regions of India. Under conducive environmental conditions, niger is susceptible to various diseases, among which leaf spot caused by Alternaria spp. is one of the most predominant, leading to significant yield losses. In recent years, the area under niger cultivation has increased in the Konkan region of Maharashtra. Therefore, the present study was conducted to assess the influence of weather parameters on the development of Alternaria leaf spot of niger (Guizotia abyssinica L.) under Konkan agro-climatic conditions during the Kharif season of 2024. Methodology: Field experiments were carried out at the Department of Plant Pathology, College of Agriculture, Dapoli, and disease severity was recorded using a 0–9 disease rating scale. The calculated disease severity was correlated with prevailing weather factors. Results: During the experiment, disease initiation was observed from the 39th standard meteorological week, with PDI ranging from 2.19% to 44.44%. Correlation analysis revealed that maximum temperature (r = 0.923) was significantly and positively associated with disease intensity at the 5% level. In contrast, minimum temperature, morning and evening relative humidity, rainfall, and wind speed showed negative but non-significant correlations with PDI, while bright sunshine hours showed a non-significant positive association. Conclusions: The results highlight that maximum temperature one week prior to disease observation played a critical role in influencing disease severity. The study underscores the importance of weather-based disease monitoring, which can facilitate the development of forecasting models and timely management strategies to reduce yield losses in niger cultivation.

• 1.   Ranganatha, A.R.G. 2013. Niger technology for maximizing production. Published by Project coordinator, All India Coordinated Research Project on Sesame and Niger, ICAR, JNKVV Campus, Jabalpur. pp. 1-18.
• 2.   Doggett, H. 1987. Niger (Noug) research methodology In Oil Crops: Niger and Rapeseed/Mustard. Proceedings of the Third Oil Crops Network Workshop held in Addis Abeba, Ethiopia, 6-10 October (A. Omran, Ed.). pp. 210-219.
• 3.   Anonymous 2024. Area, Production and Productivity of Niger seed in India (1964-1965 to 2023-2024-3rd Advance Estimates.
• 4.   Anonymous 2023. Final Advance Estimates of Area, Production and Productivity of Crops in Respect of Maharashtra State for the Year 2022- 23.
• 5.   Patil, C. B. and Patil, B. B. 1981. Niger cultivation in Maharashtra. Indian Farming, Feb.: 13-14.
• 6.   Nagaraja O., Krishnappa M. 2016. Detection and Seed Transmission of Alternaria porri in Niger. Int. J. Curr. Res. Acade. Rev. 4(10): 66-74.
• 7.   Sandipan, P.B., Jagtap, P.K. and Patel, M.C. 2014a. Sources resistance in screening of elite material in niger (Guizotia abyssinica Cass) genotypes against Alternaria and Cercospora leaf spot diseases under natural condition. Asian J. of Sci. Tech. 5 (8): 491 – 496.
• 8.   Mayee, C.D. and Datar, V.V. 1986. Phytopathometry. Tech Bull-1 Marathwada Agric. Univ., Parbhani. p. 66.
• 9.   Wheeler, B.E.J. 1969. An introduction to Plant Diseases. John Wiley and sons Ltd., London.
• 10.   Hosalli, S. 2005. Studies on self fertility and autogamy in niger (Guizotia abyssinica Cass.). M.Sc. (Agri.) Thesis submitted to the University of Agricultural Sciences, Dharwad.
• 11.   Kivadasannavar, P., Deshpande, V.K. and Vyakarnal, B.S. 2007. Effect of sowing time, spacing and fungicidal spray on crop growth and seed yield of niger (Guizotia abyssinica Cass.). Karnataka J. Agril. Sci. 20 (4): 848-850.
• 12.   Sharma, S., Ratnoo, R.S. and Jain, H.K. 2020. Correlation of date of sowing and weather factors on the disease progression of Alternaria blight of Niger. J. Pharmacognosy and Phytochem. 9(1): 2130-2134.

Data Sharing Statement

Funding