The Plant-growth Stimulating Properties of Ethylene-bis-nitrourethane and Related Compounds

Abstract

Ethylene-bis-nitrourethane (EBNU), NN'-dinitroethylene urea, and ethylene dinitramine were found to increase the growth of some broad-leaved plants (peas, broad beans, and tomatoes), grasses and cereals. Other plants were un affected, and furthermore experiments with peas showed pronounced differences between the responses of several varieties of one species. Treatment of dicotyle dons increased the growth of the stem by promotion of internode extension pos sibly based on enhanced cell growth. Leaf areas and dry weights were less affected. The leaf length of cereals was increased, and small improvements in the dry matter yield of grass were obtained in field experiments. Stimulated plants re mained relatively normal in appearance, and in some cases the effect of a single treatment with EBNU persisted throughout the entire vegetative development. In some respects the effects of EBNU resembled those of gibberellic acid, but important differences were found when the two chemicals were applied to a number of pea varieties, and when internode growth-rates were measured. EBNU and related chemicals stimulated the later stages of internode growth, high rates pro longing the period over which the internodes extended. It is suggested that they may antagonize processes leading to the cessation of cell growth. Pot and field trials suggest that the activity of EBNU is not sufficiently great to make it useful in agricultural practice. It is also known to be dermatitic, and its relatives are explosive.