Physiological aspects of Andropogon gayanus and its compatibility with legumes

Andropogon gayanus is a C4 grass, with stomata that are insensitive to low air humidity. It is tolerant to tissue desiccation and capable of efficiently using the water in the soil profile during dry periods while maintaining its photosynthetic and metabolic activity, even under conditions of severe drought. It can regrow rapidly at the onset of rains. It is resistant to burning. When shaded, it reacts by elongating its stems and mobilizing its reserves to expand its photosynthetic surface at the expense of the development of stems and roots. It shows intermediate aggressiveness in competition with legumes in association, and is less aggressive than Brachiaria decumbens and Panicum maximum under the conditions of the Quilichao Experiment Station in Colombia. Severe defoliation and/or grazing apparently reduces its aggressiveness and favors the growth of associated legumes. Experience suggests that species of Centrosema will be more compatible with this grass than are other legumes such as species of Stylosanthes and Desmodium.