Studies on the factors influencing inhibition of lateral buds and branches

Abstract

The roles of light, nitrogen and I.A.A. in particular, have been investigated and evaluated in terms of their relative importance in the outgrowth of lateral buds.

Both nitrogen and light are shown to be major factors in tillering of ryegrass and in addition that high nitrogen levels alone induce tillering in an apparently specific manner. This is in contrast to corresponding light treatments where such specific effects did not occur. The dynamics of the protein and non protein nitrogen fractions are discussed relative to the effects of the above two factors on tillering.

The inhibitory effects of I.A.A. are demonstrated though the magnitude of these is very small compared with the effects of nitrogen. Results indicate that the I.A.A. inhibition acts through a nutrient diversion mechanism and that purines or purine derivatives particularly, are concerned in the overcoming of such inhibition.