Alex Machio Kange and Eric Mosota Rosana /Afr.J.Bio.Sc. 4(1) (2021) 19-30 Page 19 of 30 Volume 4, Issue 2, April 2022 Received : 12 August 2021 Accepted : 17 February 2022 Published : 05 April 2022 doi: 10.33472/AFJBS.4.2.2022.19-30 Article Info © 2022 Alex Machio Kange and Eric Mosota Rosana. This is an open access article under the CC BY license (https:/ / creativecommons.org/ licenses/ by/ 4.0/ ), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. A bstract Late blight disease of Irish potato is caused by an Oomycete Phytophthora infestans is one of the severe crop diseases worldwide that leads to poor production of Irish potatoes. The knowledge in management of the pathogen in terms of variation of nutrition and fungicide in the cultivation of potato remain limited. This study was conducted to determine the effects of nutrition and fungicide variation in relation to potato variety in management of P. infestans in potato crop. The experiment was conducted at Egerton University and Tumaini sites in a randomized complete block design - a split -split plot arrangement with Kenya sherekea and Dutch robjin potato varieties with treatments rates of N-P-K 17:17:17 fertilizer at 0, 90, 135 kg ha -1 and fungicide, Acrobat, 0, 2.5, 3.5 g/ L. There was significant (p  0.05) difference in among the varieties, sites, fertilizer and fungicide levels for disease severity and incidence in the management of late blight in potato crop thus a potential in reduced cost of production and increased yield. Keywords: Phytopthora infestans, potato, variety, fertilizer, fungicide 1. Introduction Irish potato (Solanum tuberosum L.) is globally considered as a significant non-grain crop grown for human consumption and the fourth important food crop after maize (Zea mays L.), rice (Oryza sativa L.), and wheat (Triticum aestivum L.) (Cunnington, 2008 ). Universally, the total yield is at least 300 million metric tons cultivated in over 120 countries, food securing a minimum of a billion population (Ghimire et al., 2020). In developing countries, potato is a significant crop whose production has almost doubled in the recent decades with a corresponding increase in consumption (Mengui et al., 2019). In Kenya, potato is the second after maize in terms of staple food crops and plays a key role in food security (Muthoni and Nyamongo, 2009). It is highly affected by drought stress because of its shallow root system (Ghimire et al., 2020). However, the production is influenced by biotic stresses of disease causing pathogens (Rosana et al., 2017 ). Its susceptibility to an Oomycete, P. infestans (Mont.) De Bary that causes late blight disease that attacks all vegetative and reproductive parts of plants is one of the most severe diseases of potatoes that reduces yield (Agrios, 2005; Ghorbani et al., 2004; and Lontsi et al., 2020). * Corresponding author: Alex Machio Kange, School of Pure and Applied Sciences, Bomet University College (A Constituent College of Moi University), P.O. Box 701-20400, Bomet, Kenya. E-mail: machiopj@gmail.com 2663-2187/ © 2022 Alex Machio Kange and Eric Mosota Rosana. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. African Journal of Biological Sciences Journal homepage: http:/ / www.afjbs.com Effects of fertilizer and fungicide application rates on late blight disease and growth of Irish potato ( Solanum tuberosum L.) Alex Machio Kange 1,2* and Eric Mosota Rosana 2 1 School of Pure and Applied Sciences, Bomet University College (A Constituent College of Moi University), P.O. Box 701-20400, Bomet, Kenya. E-mail: machiopj@gmail.com 2 Department of Crops, Horticulture and Soils, Faculty of Agriculture, Egerton University, P.O. Box, 536-20115, Egerton, Kenya. E-mail: ericmosota@yahoo.com Research Paper Open Access Alex Machio Kange and Eric Mosota Rosana /Afr.J.Bio.Sc. 4(2) (2022) 19-30 https://doi.org/10.33472/AFJBS.4.2.2022.19-30 ISSN: 2663-2187