Reactions of sorghum-sudangrass hybrids and pearl millet to three species of Meloidogyne.

Sorghum-sudangrass hybrids and pearl millet, Pennisetum americanum (L.) Leeke., are grown extensively in the southeastern United States; the former is used for forage, seed, and summer cover crop and the latter, primarily for grazing, forage, and summer cover crop. The extended period during which these crops can be planted makes them especially adapted to a doublecropping system with winter-grown small grain or vegetable crops. Sorghum and millet follow most crops in rotation without serious cultural and disease problems (3), but many plant-parasitic nematodes that parasitize other crops also attack sorghumsudangrass hybrids and pearl millet (2). McGlohon et al. (5) found that, in North Carolina, sudangrass [Sorghum sudanense (Piper) Stapf] supported reproduction of Meloidogyne javanica (Treub) Chitwood and M. incognita (Kofoid g: White) Chitwood, and that 'Starr' millet [P. americanum (L.) Leeke.] did not support growth and reproduction of Meloidogyne. Preliminary observations indicated that, under field conditions, M. incognita attacks certain varieties of pearl millet. The objective of this study was to determine the reaction of important sorghum-sudangrass hybrids and pearl millets to three species of this genus. Seeds of the selected hybrids were planted in 5-cm clay pots containing methyl bromide-treated (0.45 kg/1.4 m s) Tifton sandy loam (85% sand, 10% silt, 5% clay). Seedlings of uniform size were selected after 2 weeks and transferred singly to 15-cm clay pots containing the medium described previously. A complete nutrient solution [840 gm of a commercial fertilizer, VHPF® (Miller Chemical Com-