Agricultural and municipal compost residues for control of root-knot nematodes in tomato and pepper

The efficacy of olive (Olea europea) pomace (OF), chicken litter (CL), and municipal compost residues (MCR) as soil amendments for control of root-knot nematode (Meloidogyne javanica) was studied in shadehouse and field microplot experiments. Results from a shadehouse experiment with green pepper (Capsicum anuum) demonstrated that plants in soil amended with MCR, OF, and MCR+OP had lower numbers of M. javanica in the roots than those grown in unamended control soil. Ammoniated OP (treated with NH3) was not as effective as the other amendments for nematode control. Amended soils exhibited higher esterase activity than control soil and numbers of nematodes per gram of root were inversely related to soil esterase activity. In a field microplot experiment with tomato (Lycopersicon esculentum) highest yields in soil fumigated with methyl bromide and infested with the nematode after fumigation were obtained with CL+OP amendments; highest yields in nonfumigated soil also infested with the nematode corresponded to treatments with MCR+OP, CL+OP, and CL. Most amendments in the microplot experiment were suppressive of M. javanica. Numbers of M. javanica juveniles in unamended, methyl bromide-treated soil were higher than in unamended unfumigated soil at harvest. Esterase activity was higher in amended soils than those without amendments irrespective of whether the soils had been treated with methyl bromide or not. Numbers of nematodes per gram of root were inversely related to soil esterase activity in unfumigated soil but not in soil treated with methyl bromide. Juvenile population densities in soil were inversely related to esterase activity in both fumigated and unfumigated soil. However, the model describing the relationship between the two variables indicated a more rapid decline in nematode numbers with increasing enzymatic activity for unfumigated soil than in methyl bromide-treated soil.