Management of Meloidogyne incognita in cotton with nematicides.

Four field trials were conducted in Georgia, U.S.A. over two years to compare rates of 1,3-dichloroproprene (1,3-D), aldicarb and their combinations on the growth of cotton in producer fields infested with Meloidogyne incognita. 1,3-D was injected 30-cm-deep with a single in-row chisel two weeks prior to planting. Three rates of aldicarb were applied in-furrow during the planting operation. In three of the tests, an additional sidedressing application of aldicarb was placed into the soil at 2.5-cm-deep and 15 cm on either side of the cotton plants at 24 to 28 days after planting. Cotton lint yields varied by location and year but were improved with 1,3-D (32 kg a.i./ha) + aldicarb (0.59 kg a.i./ha), aldicarb (1.17 kg a.i./ha), and aldicarb (0.87 kg a.i./ha) + aldicarb sidedress (1.17 kg a.i./ha). The 1,3-D (32 kg a.i./ha) + aldicarb (0.59 kg a.i./ha) treatment provided the most consistent and greatest yield improvement over controls, while relative cotton yield in specific aldicarb treatments varied among tests. Plant stands, plant height, and root knot nematode numbers generally did not differ among treatments. Based on data from these tests, 1,3-D and aldicarb, alone or in combination, can be recommended for management of M. incognita in Georgia cotton production systems.