Ear Formation in Timothy Grass (Phleum pratense) following Vernalization and Short-day Treatments

Abstract

IN many perennial grasses of temperate regions, exposure to low temperature has proved to be a necessary condition for the attainment of the reproductive phase. After vernalization, flowering may occur directly in response to long-day conditions in some grasses¹, or after initial treatment with short days followed by transfer to long photoperiods in others^2,3. The precise requirements of timothy grass have so far remained unknown, except that it flowers in long days⁴ and that spring sowings may lead to ear formation in the same year². In view of the agronomic importance of the plant, some clarification appeared desirable.