Thidiazuron (TDZ) is a

plant growth regulator Plant hormones (or phytohormones) are signal molecules, produced within plants, that occur in extremely low concentrations. Plant hormones control all aspects of plant growth and development, including embryogenesis, the regulation of organ si ...

Applications

Plant growth regulator

The synthesis routes and their use as plant growth regulating agent were patented in the early 1980s by the German company

Schering AG Schering AG was a research-centered German multinational pharmaceutical company headquartered in Wedding, Berlin, which operated as an independent company from 1851 to 2006. In 2006, it was bought by Bayer AG and merged to form the Bayer su ...

. Thidiazuron is taken up by the leaves and has a

cytokinin Cytokinins (CK) are a class of plant hormones that promote cell division, or cytokinesis, in plant roots and shoots. They are involved primarily in Cell (biology), cell growth and cellular differentiation, differentiation, but also affect apical ...

-like behavior. It causes leaves to lose weight in a controlled manner prior to harvesting, without affecting the growth and maturation of the plant. This facilitates mechanical harvesting. It also accelerates the maturation process, because leaves do not block the sunlight. The plants later develop normal

foliage A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, f ...

. Thidiazuron can also be used as a herbicide, because an appropriate dose and timing of administration completely stops growth. The product was marketed by Aventis CropScience; later merged into

Bayer Bayer AG (English: , commonly pronounced ; ) is a German multinational pharmaceutical and biotechnology company and is one of the largest pharmaceutical companies and biomedical companies in the world. Headquartered in Leverkusen, Bayer' ...

CropScience. Brand names are Dropp (for use in the cultivation of cotton) or Revent (for use in fruit production). Dropp Ultra, Dropp UltraMax and Ginstar are products with a mixture of thidiazuron and diuron.

Preservative

Researchers found that thidiazuron is suitable for extending the life of cut flowers. The substance slows down or prevents the wilting of the leaves.

Regulatory

European Union

In 2008, the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

banned the use of thiadiazuron in agriculture. It was one of the agricultural chemicals in the framework of the European Pesticides Directive 91/414 / EEC that must have an environmental and health assessment to obtain a new authorization. An outdated substance is an active substance which was already on the market in the European Union on July 25, 1993, before the action step of the directive. Existing stocks could still be used afterwards for one year. Thidiazuron is still used in other parts of the world, including in the United States, Australia, and Mexico.

Toxicology and safety

Thidiazuron is mildly acutely toxic, irritating to skin and eyes, and may cause respiratory irritation if inhaled.

References

{{reflist Herbicides Ureas Thiadiazoles Plant growth regulators Group 14 herbicides