FORAGE YIELD AND DIGESTIBILITY OF AFRICAN PEARL-MILLET LANDRACES IN DIALLEL WITH MISSING CROSS

Shortage of nutritious forage is limiting animal production in the sem iarid regions of Africa, This study was conducted to evaluate the magn itude of heterosis for forage production and dry matter digestibility in African landraces of pearl millet [Pennisetum glaucum (L.) R. Br,]. Five landrace populations, 9 of 10 interpopulation crosses, and two h ybrids were evaluated in a randomized complete-block design with five replications for dry matter forage yield and in vitro dry matter diges tibility (IVDMD) in 1989 and 1990 in Tifton, GA, Entries in only two r eplications were evaluated for digestibility. The missing cross was es timated, and both the traditional and Gardner-Eberhart analyses were p erformed, Highly significant difference between crosses (9.94 t ha(-1) ) and parents (8.50 t ha(-1)), or average heterosis, as well as genera l combining ability was observed in the combined analyses for dry weig ht forage yield. No other partitions of entries for either trait were significant. Year x entries was significant for forage yield but not f or IVDMD. All midparent and high-parent heterosis values were positive for forage yield but were nonsignificant. High-parent heterosis value s ranged from 3.3 ('Iniari' x 'Mansori') to 22.9% (Iniari x 'P(3)Kolo' ) for dry matter forage yield. No heterosis was observed for IVDMD. He terosis for forage yield did not affect IVDMD. These results suggest t hat use of pearl millet hybrids can contribute to increased forage pro duction in semiarid Africa.