Prevalence, Severity, and Distribution of Potato Cyst Nematode in Nyandarua and Nyeri Counties, Kenya

Purpose: Potato cyst nematode (PCN) Globodera rostochiensis W. is a major soil borne pest of potato globally. In Kenya, it was reported for the first time in Nyandarua County in 2015. There exists a knowledge gap in understanding the population dynamics of PCN under different farming systems and environmental conditions, which shows that it is essential for developing sustainable management strategies.Research Method: A base line survey was conducted to identify and map out PCN incidence and infestation in Nyeri and Nyandarua Counties. Soil samples were collected from 75 farms from a population of 500 farmers registered in farmers’ groups and community-based organizations following purposive, stratified and simple random sampling methods. PCN incidence, infestation, infectivity, yield loss estimation and soil chemical characteristics were determined. Analysis of variance (ANOVA), Chi-Squared test and correlation tests were applied in analysis using R version 4.4.0.Findings and Values: There was a significant difference in mean number of PCN cysts between the two counties; (Wilcoxon rank sum test, P