Grasses native to South Texas have an increasing demand for use on right-of-way cover, for soil stabilization, rangeland recover, and wildlife habitat improvement. Previous research identified plains bristlegrass collections, which proved to be valuable for such use. As seed demand by ranchers and public organizations raises, it is essential to develop technology to effectively produce seed. In 2005 experiments were established to document seed production response to nitrogen fertilization and humic acids levels on four plains bristlegrass accessions. Experiments were established in two locations with different annual mean temperature. The plains bristlegrass accessions 648, 677, 715 and 820 were planted at Beeville and Stephenville, Texas. Nitrogen fertilization treatments imposed consisted of 0, 50, 75, 100 and 140 kg ha^-1. At Beeville, application of humid acids was tested vs. a control. Granular humic acids were applied to the soil at 730 kg ha^-1; and 9 kg ha^-1 of humic acids suspended in water were sprayed onto the plants. Experiments at both locations were conducted under irrigation. The experimental design was a factorial 4 x 5 x 2 (four grass accessions, five nitrogen levels and two sites). Seed yield and seed germination responses to the management treatments imposed were generated.