Diversity of Plant Parasitic Nematodes of Tree Tomato (Solanum betaceum Cav.) In Kiambu and Embu Counties, Kenya

Abstract

Surveys were conducted in five areas representing different agro-ecological zones (AEZs) in Kiambu and Embu counties in Kenya during January to April 2019 cropping season to determine population density, genera diversity and distribution of plant parasitic nematodes associated with tree tomato farming systems. Nematodes were extracted from 200cc of soil or 5g of roots using modified Baermann technique. The nematode diversity and evenness in the study areas were determined using Shannon and Simpson’s indices respectively. Soil nutrients were determined using Mehlich double acid digestion. A structured questionnaire was used to get information on farming practices from sampled farmers. Meloidogyne spp. was the most dominant genera followed by Pratylenchus spp. and Helicotylenchus spp. in both soil and root samples. Githunguri recorded significantly high mean number of 15.92 and 4.29 nematodes in soil and root samples respectively. Kiambaa had the highest diversity index of 1.59 and 0.86 in soil and roots respectively while genera richness was highest in Kiambaa with 13 nematode genera in soil. Simpson’s index of evenness was highest in Kiambaa with 0.69 and 0.47 in soil and root samples respectively. Githunguri had the high egg mass index of 2.00. Soil texture and elements of C, P, K and N together with farming practices may have contributed to the nematode community structure in the study areas.