Response of geographical strains of grasses to low temperatures

Rogler, G.A.

Response of geographical strains of grasses to low temperatures

1943

Rogler, G.A.

The purpose of this study was to obtain information on the resistance to low temperature of seedlings and mature plants of geographical strains of grasses. Agropyron cristatum, A. smithii, and Bromus inermis are classified as cool temperature species because they make their maximum vegetative growth in the cool period of the growing season. Bouteloua gracilis, B. curtipendula, Andropogon furcatus, and Panicum virgatum are classified as warm temperature species because they make their maximum vegetative growth during the warmest period of the growing season. Strains of the warm temperature species from the same general geographic origin react similarly to the winter climate at Mandan, N. Dak. The average field survival of these species decreases as their origin becomes more southerly. There has been no injury to the cool temperature species in the field regardless of origin. There is a definite tendency for seedlings of warm temperature species of northern origin to survive in greater proportion after artificial freezing than those of more southern origin. With cool temperature species the only significant differences were obtained with A. smithii. Seedlings of this species from the south were less resistant to cold temperatures than those from the north. Under all treatments the A. cristatum seedlings gave higher survival than those of A. smithii and seedlings of A. smithii gave higher survival than those of B. inermis.

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