GERMINATION OF 20 FORAGE LEGUMES AS INFLUENCED BY TEMPERATURE

Many studies have shown that water potential at planting will affect germination rate and final germination. Much less is known, however, about the effects of different temperatures at planting on seed germination. Our objectives were to compare the influence of different temperatures on the germination percentage and germination rate index of 20 forage legumes. Legume seedlings were grown for 10 d in polyethylene growth pouches placed in germination chambers and held in the dark at constant temperatures of 10, 15, 20, 25, or 30-degrees-C. There were major effects of temperature on germination rate and germination percentage for all 20 legume entries. If we define satisfactory germination as 80% germination at 10 d after planting, 18 of the 20 entries had satisfactory germination at some temperature between 10 and 30-degrees-C. There were no significant effects of temperatures between 10 and 30-degrees-C on germination percentage at 10 d for 'Arlington' red clover (Trifolium pratense L.) and 'Maxidor' alfalfa (Medicago sativa L.) entries. Since temperature had a strong influence on germination, seeding time for some legumes should be selected to match expected temperatures for particular locations.