Establishment of Subclover in Relation to Nodulation, Time of Seeding, and Climatic Variations

Abstract

Pellet inoculated subclover (Trifolium subterraneum) seed planted at various autumn dates on a site where effective nodulation was known to be a problem, produced healthy plants when mean ambient air temperature in the 6 weeks following germination was between 49 and 62 F. When mean temperature for the 6-week period was about 45 F, very poor clover stands developed. Seed planted September 10, about one month before a rain, produced a good stand of vigorous clover. This indicated that sufficient viable inoculum had survived in dry soil on the pelleted seed until the rains came. It is recommended that where subclover is adapted, plantings be made in October rather than waiting until after the soil is wet. More vigorous clover grew from seed which was in the ground at the time of the first rain than from seed drilled soon after the rain.