Birdsfoot Trefoil Cultivars Research Articles

EFFECT OF HARVESTING PRACTICES ON FOLIAGE AND ROOT DEVELOPMENT, DIGESTIBILITY, COLD HARDINESS AND NODULATION OF BIRDSFOOT TREFOIL

Empire, Leo, Viking and Wallace cultivars of birdsfoot trefoil were evaluated in a greenhouse experiment for total forage production, aerial and root growth, in vitro digestibility, cold hardiness, etiolated regrowth and modulation. Plants were harvested at the vegetative stage (four harvests); 10% bloom (three harvests); 50% bloom (two harvests); and maximum growth (one harvest), at two stubble heights, 2.5 and 7.5 cm. Harvesting at the maximum growth stage produced the most dry matter but the lowest digestibility, with the greatest etiolated regrowth and best nodulation. Production at the vegetative stage produced the least forage which was the most digestible. Empire was the most productive cultivar, with a hardiness rating equal to Leo. At the 10 and 50% bloom stages, Wallace equalled this cultivar in production and there was no difference between the four cultivars in forage production when harvested at the vegetative stage. Viking appeared to be the least hardy of the cultivars examined, although it produced more etiolated regrowth than Empire and Wallace but not as much as Leo. This experiment shows that criteria other than total production must be examined in evaluating birdsfoot trefoil cultivars.

EFFECT OF LOTUS RHIZOBIA STRAINS ON THE GROWTH AND NODULATION OF LOTUS CORNICULATUS UNDER FIELD CONDITIONS

The growth and nodulation of two birdsfoot trefoil (Lotus corniculatus L.) cultivars, Empire and Leo, during the year of establishment were studied in the field. Plants were inoculated with each of four Lotus rhizobia strains. Four weeks after seeding, about 92% of the plants bore nodules. After 7 weeks practically all plants were nodulated and nitrogen was being fixed. Plant dry weights and dry matter yields were greatest with Rhizobium strain 95C11 which formed large nodules on each host. With strain P, many small nodules were formed and yields were lower.

INFLUENCE OF ROOT TEMPERATURE ON THE EARLY GROWTH AND SYMBIOTIC NITROGEN FIXATION OF NODULATED LOTUS CORNICULATUS PLANTS

Three birdsfoot trefoil (Lotus corniculatus L.) cultivars, inoculated with one of six Lotus rhizobia strains or dependent on ammonium nitrate, were grown in diSPo growth pouches under controlled environmental conditions at five root temperatures (9–30 C) for 35 days after nodule formation. When the plants were dependent on symbiotic nitrogen fixation, the highest dry weights and nitrogen yields per plant were obtained at 18 or 24 C depending on symbiotic combination. At 9 and 12 C, nitrogen fixation was depressed and the growth was poor. The dry weights of plants at 9 C were 19 to 45% of those at 24 C. At 30 C the growth and nitrogen fixation were generally depressed. At all root temperatures the growth of plants dependent on symbiotic nitrogen fixation was inferior to that of plants receiving combined nitrogen (NH4NO3). Significant interactions indicate that the nitrogen fixing ability of cultivars was dependent on both root temperature and the strain of Lotus rhizobia.