Management of the Tobacco Black Shank-Root-Knot Complex with Combinations of Soil Fumigants and Metalaxyl. A. S. CSINOS, Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31793-0748. A. W. JOHNSON (USDA-ARS), Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton 31793-0748, and A. M. GOLDEN (USDA-ARS), Nematology Laboratory, BARC W, Beltsville, MD 20705. Plant Dis. 78:565-568. Accepted for publication 1 March 1994. This article is in the public domain and not copy-ightable. It may be freely reprinted with cus-omary crediting of the source. The American Phytopathological Society, 1994. DOI: 10.1094/PD-78-0565.

When applied preplant incorporated and at last cultivation (lay-by), 1,3-dichloropropene (1,3-D) at 56 L/ha, 1,3-D/17% chloropicrin (C-17) at 65.5 L and 93.5 L/ha, and fenamiphos at 5.7 kg a.i/ha + metalaxyl at 0.56 kg a.i./ha were equally effective in reducing tobacco black shank on cultivars K-326, Speight G-70, and Coker 371 Gold. Methyl bromide at 112 kg/ ha injected into the soil prior to transplanting was not effective in reducing black shank but reduced damage from root-knot nematodes in all cultivars. All treatments reduced final root-gall indices compared to the untreated control in 1990 and 1991. In 1991, final root-gall indices were higher for Coker 371 Gold, a cultivar with no resistance to Meloidogyne incognita, than for Speight G-70 or K-326, cultivars with resistance to M. incognita. Yields were increased over the untreated control by 1.3-D/C-J7 treatments at either rate for all cultivars in both years. Yields were higher with 1.3-D/C-I7 than with other treatments in 1990 and higher with enamiphos treatments in 1991 for K-326 and Coker 371 Gold. Yields for K-326 were usually higher than those for the other cultivars in all treatments both years.

Keyword(s): Meloidogyne javanica, Phytophthora parasitica var. nicotianae