Production and Natural Regeneration of Annual Medics in West-Central Texas

Several annual Medicago species have been found to be well adapted to the soils and climates of other areas of Texas, but their adaptation to west-central Texas has not been studied. We evaluated the establishment, yield, and natural reseeding potential of Medicago truncatula, M. lupulina, M. polymorpha, M. minima, and M. orbicularis on a Rioconcho clay loam/Spur clay loam soil complex near San Angelo, Texas during 1998 – 2004. All annual medics established following seeding in mid November 1998 although sub-freezing temperatures in December 1998 caused considerable seedling mortality. With one irrigation in November 1998 and above-normal winter and spring rainfall, all species produced a good seed crop in spring 1999. The medics did not establish in autumn 1999 because of dry conditions, but good establishment occurred in autumn 2000 following 8 in. of rainfall and a single irrigation in November 2000. Frequencies of seedlings ranged from 61 % for ‘Jemalong ’ barrel medic (M. truncatula) to 90 % for ‘Devine ’ little bur medic (M. minima) in late March 2001. Forage yields in early May 2001 did not diffe