The Effect of Greenhouse Temperatures on the Growth of Small Grains 1

During the pa~t few years it has been a common practice at some of the experiment stations to grow small grains in greenhouses for breeding work, for pot tests of soils, and for other similar experiments. For the crossing of varieties and the rapid increase of selected seed of small grains, the greenhouse offers almost invaluable aid, as by its use two crops of most of the grains may be grown in one year. Greenhouses are also usually more conveniently located than field plots and are therefore more accessible to the workers. When the crops are grown at the proper temperatures they set seed well and hand pollination may be practiced very successfully, It is not at all difficult to get 8o percent or more" of all crosses made to set seed when the work is done carefully. For’crossing it is usually best to grow the plants in small pots, as these may be placed in any convenient position for working and may be segregated easily after the cross is made, either by placing them in another apartment or by separating them from other plants by canvas partitions. Failures to get small grains to set seed properly in greenhouses are often reported, however. The writers believe that such failures are often due to the maintenance of improper temperatures in the houses. For this reason an experiment was conducted during the winter of I9I 5 to test the effect of temperature upon the growth of winter wheat, oats, barley, and rye grown in the greenhouse. Fulcaster wheat, Culberson oats, Union Winter barley, and Abruzzes rye were used in this exPeriment.. The seeds of th se grains were