INTRODUCTION

The problems in turfgrass management such as how to promote growth and to control disease, insects, and woods at a lower pollution level still exist. Many chemicals have been produced to deal with these problems. Some of them contain extracted cytokinin from plants which can promote growth. Some are multi—function fungicides which not only can kill fungi, but also can regulate the growth of turfgrass..

The -function of cytokinin in plants has been known well.. summarily, it can retard senescence (Richmond and Lang, 1957); can prevent the senescence—related changes in chioroplasts (Kursanov and Kulaeva, 1964; Shaw and Manocha, 1965; Dennis, et al.., 1967). Not only, do Cytokinin retard the loss of chlorophyll, but they exert a similar effect on the protein and RNA constant of detached leaves (Richmond and . Lang, 1957; Person et al -, 1957) - One of the most important physiological effects produced by cytokinin is the directed transport or mobilization of solutes toward the site of cytokinin application (Nothes, 1959).. Zinc (1961) treated a wide variety of leafy vegetables with benzyladenine and found that loss of chlorophyll was delayed and the damage by fungi and bacteria was reduced.

Cytokinin should respond to growth, development and cOlor, of grasses. - However, there are few papers which discuss the. cytokinin and the effect of cytokinin-like chemicals in turfgrass. The effect of cytokinin level in control the movement of redistribution of nutrients is not known.

Bioassay Experiment

Cotyledons of radish ( Raphanus sativus ) were used as bioassay material (~7..H. Yopp, 1986). The cotyledons were laid on the chemical treated filte papers in petri dishes, incubated in a growth chamber at 25 degrees centigrade and with 550 lux cold white fluorescent light. After three days incubation, the cotyledones wee blotted dry and weighed. Using the 6-benzylaminopurine (BA) as the standard material to make the standard curve about its concentration and growth. The biological activity of other growth regulators were compared with the standard material.

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