Developing germination models from air and soil temperature

Abstract

Germination models were developed in a growth chamber study for four cool season grasses; Kentucky bluegrass, chewing fescue, tall fescue, and perennial ryegrass. These models were applied to a field study where air and soil surface temperatures were measured. Both air and soil surface temperature models better predicted growth in fast-germinating species. Perennial ryegrass, which had the fastest germination of all species, germinated on the day predicted by the air temperature model. Estimates from the air temperature models tended to be a few days earlier than those from the soil surface temperature models; however, the estimates were considered to be similar. Due to the fact, for ease of use we recommend using the air temperature models.