Identification and management of root knot nematodes (Meloidogyne spp.) attacking chickpea (Cicer arietinum l.) in Nakuru County, Kenya using nematicides and cultural practices

Abstract

Root knot diseases are known to attack many crops especially legumes such as chickpea. Losses due to root knot nematodes (Meloidogyne spp.) in chickpea have been approximated at 13.7% of yield loss which translates to loss of billions of shillings annually. Four main Meloidogyne species; M. hapla, M. javanica, M. arenaria and M. incognita attack chickpeas. Experiments were conducted in the greenhouse to characterise, identify and control Meloidogyne spp. causing root knot disease in chickpea in Nakuru County. Characterization and identification were done using perineal patterns procedure on female root knot nematodes. Three treatments; poultry manure, two commercial nematicides and Sudan grass (Sorghum sudanese) were used in this study. Poultry manure was used at three levels; 250 g, 500 g, 750 g and control. Marshal 250 EC nematicide was used at 10 ml/ litre of water, 25 ml/ litre and 50 ml/ litre as low, recommended, high doses respectively. Nimbecidine nematicide was used at 3.5 ml/ litre of water, 7 ml/ litre and 14 ml/ litre as low, recommended, high doses respectively and control in each treatment. Completely randomized design was used in the study as a design for treatments. Thirty samples of Meloidogyne spp. female were used during characterisation and all had uniform perineal patterns similar to that of M. javanica distinguished from other species by a distinct lateral ridge separating dorsal and ventral arch. M. javanica was the main root knot species attacking chickpeas. There was significant difference (P=0.05) in root galling and M. javanica juveniles population reduction between positive control (zero grams) and other poultry manure treatments. The nematicides significantly reduced root galling and number of juveniles at recommended and high levels. Marshal 250 EC was an effective nematicide than Nimbecidine and Marshal 250 EC which recorded the lowest root galling and number of juveniles as compared to Nimbecidine. There was no significant difference (P=0.05) in results of 250 g, 500 g and 750 g poultry treatments. There was significant difference (P=0.05) between results of Sudan grass, positive and negative control. Poultry manure and Sudan grass treatments significantly reduced root galling and nematodes juvenile population. There was a relationship between root galling and juvenile number in soil, root galling and root weight per chickpea plant. The findings of this study will benefit farmers on choice of commercial nematicide to use against root knot nematodes to maximize yield of chickpea. The findings can also be used by farmers to manage root knot disease using cover crops such as Sudan grass.