Root-knot Nematode Populations and Carrot Yield Following Five Forage Legumes and Continuous Carrots

Abstract

Abstract Root-knot nematode (Meloidogyne hapla) juvenile population increased and carrot (Daucus carota L.) yield progressively decreased during eight continuous carrot crops grown over 37 months. When ‘Haifa’ and common white clovers (Trifolium repens L.) were cropped for 29 months and plowed down, two succeeding carrot crops suffered severe yield and quality losses and the juvenile nematode population in the soil in-creased greatly. However, there were significantly fewer juveniles in the soil and significantly higher yield and better quality of carrots when nematode-resistant ‘Nevada Synthetic XX’ and ‘Nevada Synthetic YY alfalfas (Medicago sativa L.) and continuous cultivation preceeded the carrots.