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

Abstract

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.