VEGETATIVE PROPAGATION OF WILD OATS, AVENA FATUA, AND OTHER ECONOMICALLY IMPORTANT SPECIES OF AVENEAE AND HORDEAE

Abstract

Following the discovery that small sections of wild oats seedlings could become rerooted and develop into normal plants, a study was undertaken to determine from what part or parts of the seedlings new growth can originate, and whether cultivated oats, wheat, barley and spring rye, would behave in a similar manner. Special attention was given to the problem of vegetative propagation in wild oats as a factor in the control of this weed.Small sections of wild oats seedlings, one inch in length and containing the coleoptile node, became rerooted under favorable conditions and produced fully developed plants. Cultivated oats behaved in a similar manner to wild oats in this respect, but the latter produced the more vigorous growth.When land is infested with wild oats and is plowed shallow, or cultivated shortly after the seedlings have emerged from the soil, a considerable proportion of them, under certain conditions, may produce new plants by vegetative regrowth. The extent to which this may occur in the field depends largely on the soil moisture as well as on other conditions which facilitate rerooting, such as shallow plowing, and packing when conditions for plant growth are favorable.With young seedlings of wild oats at time of emergence, regrowth occurred mostly from a small area located between ground level and one inch below the surface. The same was found to be true of cultivated oats. With seedlings of wheat, barley and spring rye, at time of emergence, regrowth originated only from nodal tissue close to the seed. The difference in this respect, between oats, Aveneae, on the one hand, and wheat, barley and rye, Hordeae, on the other, is due to the fact that the area of elongation in oats is the mesocotyl, whereas in other cereals it is the first internode.At later stages in seedling development of both oats and the other cereals, nodes which were capable of regrowth developed immediately below and above the ground level. With older seedlings in the first-, second-, and third-leaf stage, the youngest node above ground, which is the one nearest the soil, had the greatest power of regrowth.