Bionematicides for management of root knot nematode on tomatoes

Root-knot nematodes (Meloidogyne sp.) are widely distributed throughout California and are the most important nematode pest of tomatoes ( Solanum lycopersicon). Current control methodology relies on the use of Metam sodium, 1,3-Dichloropropene (Telone II, 1,3-D), and nematode resistant varieties. During two years of field trials on tomatoes, QL Agri, Meadowfoam, Neem Cake, DiTera, and Root Feed were tested and compared to an untreated control and a chemical standard (1,3-D) for management of root knot nematode ( Meloidogyne javanica). Each trial consisted of five replicates of 6 or 8 treatments in a randomized complete block design. At harvest, DiTera (P <= 0.05) and Neem Cake (P <= 0.05) both had a greater average size of tomatoes than 1,3-D. DiTera also had a greater average size of both red (P <= 0.10) and green tomatoes (P <= 0.05) than 1,3-D. A QL Agri + Meadowfoam treatment had a greater yield of red tomatoes than 1,3-D (P <= 0.10). Numerically, all treatments except Meadowfoam had a lower root gall rating at harvest than untreated. Numerically, root-knot juveniles in the soil at harvest were lower than the untreated for the high rate of QL Agri, QL Agri + Meadowfoam, DiTera DF and 1,3-D. Several of the products tested appear to have value in managing nematode effects on tomatoes. Some of the products tested have also been observed in various trials to possibly act as plant growth regulators stimulating growth of roots or shoots even in the presence of nematodes.