November 22, 2021

Development of New Varieties of Fungicides

I. Development status of triazole fungicides

The development of triazole fungicides has been particularly notable since 1973 when Bayer introduced the first commercialized fungicide triadimefon with chiral carbon. With its rapid development, the number of fungicides is unmatched by any previous fungicides. At present, about 40 varieties of these fungicides have been commercialized, of which seven varieties have been developed in recent years.

Triazole fungicide's chemical structure on the common feature is the main chain contains a hydroxyl (ketone group), substituted phenyl, and 1, 2, 4 - triazole group compounds. These agents are active against pathogens of the subphylum Cysticercus, Streptomyces, and Hemiptera, except for oomycetes of the subphylum Flagellum, which are inactive. The mechanism of action is to affect the sterol biosynthesis so that the bacterium cell membrane function is disrupted. It has been applied for many years, but no resistance has been found in pathogenic bacteria.

In the 1970s, triazolone entered the pesticide market and showed the prospect of triazole pesticide development with its excellent efficacy, and then a series of active structures were developed successively. In addition to bacterial inhibition, triazole pesticides also have physiological regulating effects on plants, change binding groups, and obtain insecticidal and herbicidal activities. These fungicides are widely used, and their mode of action is different from that of previous fungicides, and their biological activity has great potential. In conclusion, with the progress of research work on compounds with triazole as the active structural component, more new varieties will emerge.

In recent years, triazole fungicides have started to be strongly influenced by strobilurin fungicides due to their resistance and activity problems, but these fungicides still occupy an important position in the world pesticide industry, such as tebuconazole, fluconazole, and propiconazole with sales of $200, $130 and $115 million respectively in 1999, tebuconazole and epoxiconazole with sales of $2.01 and $1.52 in 2002. The sales of tebuconazole and epoxiconazole in 2002 were $201 and $152 million, respectively.

2. A new generation of fungicides - strobilurin class fungicides

The development of fungicide markets in the world's leading countries in the last five years has been driven by the new generation of fungicides - strobilurin-based fungicides. The products based on these fungicides are azoxystrobin from Syngenta, Kresoxim-methyl from BASF, and, more recently, trifloxystrobin from Bayer. Products with these fungicides as active ingredients have been registered in all important fungicide markets in the world, including Japan and the United States. The rapid development of Strobilurin-based products in the European market has generated some controversy. This is because, in the last two years, these products have become resistant to cereal mildew in the northern German market, where they were first introduced. This has led to the creation of the Fungicide Resistance Committee (FRAC) guidelines. The guidelines guide farmers on the number of applications of these products in any given season. The Strobilurin class of fungicides has now developed into a major fungicide species in the European cereal market.

3. The development of the fungicide market

The intensification of agricultural production can increase the demand for fungicides. In low-intensity agricultural production, the biggest threat to crop yield is the weeds that compete for sunlight, nutrients, and water. However, as agricultural intensification continues, the disease will become the biggest factor negatively affecting crop yields.

In addition, the emergence of plant disease resistance to fungicides is not only a challenge but also an opportunity for fungicide manufacturers to grow. Research and development-based pesticide companies have sought to extend the life of a variety to compensate for the significant cost of developing it. However, the emergence of resistance in plant pathogens has ensured that there is a demand for new fungicides with new and outstanding mechanisms of action. The share of fungicides in total pesticide sales in different countries is governed by several factors, including climatic factors and the efficacy of the products used. The current situation shows that Japan, which is the most supportive of intensive production, and France, Germany, and the Netherlands, which are among the European countries, have the highest proportion of fungicide products. In the world's three largest fungicide markets: France, Japan, and the United States in the next five years, its fungicide growth potential is limited. This is determined by several factors affecting the entire pesticide industry in these countries, but this does not mean that the importance of these countries' fungicide market will be reduced. France is the world's largest fungicide market. The Japanese fungicide market has been declining in the last three years, but this does not represent the Japanese fungicide market demand.

The market is dominated by cereal fungicides, and in recent years by strobilurin-based fungicides. The European fungicide market is largely dependent on farm income subsidies granted under the European Union agricultural policy. Several new member states will join the European Union, so the European Union agricultural policy will be further revised before then. Over the next five years, the development of the European market will depend on the new EU agricultural policy. In Asia, China, India, and South Korea are the three fungicide markets with the greatest growth potential. Each market is ranked in the top ten fungicide markets by their fungicide sales, and their growth potential will be most favorable to the pesticide industry. The large population problems in China and India and the rapid industrialization of these three countries will contribute to the intensification of agricultural production. With the expiration of the patents of several highly effective triazole fungicides, the Chinese and Indian markets will also gain development.

4. Development suggestions

① further supports the creation of new fungicides. The implementation of the Intellectual Property Law and China's imminent entry into the WTO, and then completely relying on imitation of foreign products have been very difficult, for this reason, the state invested a lot of money to set up two pesticide creation centers in the north and south. The creation of our new fungicide varieties, which should be further fostered, so that China's pesticide business to a higher level.

②focus on the development of targeted new varieties. Compared with the other two categories of pesticides, China's fungicide varieties are relatively small, benzimidazoles, triazoles, and even some traditional products such as Dyson still occupy the main market. These products have been used for more than a decade or even decades, and many varieties have developed serious resistance. For this reason, the development of different mechanisms of action, novel structure of the fungicide should be the focus of research and development of China's fungicide industry today.

③ the development of new varieties should carry out sufficient market research, do not go up in a flurry. The development of a new species must conduct adequate market research, especially some species ready to enter the international market. Some traditional old products, should stabilize their output, pay attention to technical transformation, try to improve product quality, change its dosage form, enter the world market, to ensure the market share of the product.

④strengthen the mix of research to develop more varieties. Any fungicide product should strengthen the research of its mixed formulations. At present, China's fungicide formulations are very single, most of the processing for single agents, mixing varieties are very few. But the mix of fungicides is not simple, but also with insecticides, herbicides, as well as after full testing and research, to obtain the scientific formula. Such fungicides should be mixed with different mechanisms of pharmaceuticals to avoid cross-resistance, and fungicides mixed with insecticides should pay attention to the consistency of disease and pest time.

⑤ Expand the field of application, to develop new markets. Many fungicides are also very good industrial mildew inhibitors, such as carbendazim, chlorothalonil, etc. But many fungicides are only used in agriculture, which can be further applied research to develop its new uses and markets.

In short, in the next five years, the world's leading markets for fungicides: Europe, the United States, and Japan is unlikely to see rapid growth, but these countries will be more restrictive factors on the pesticide market than on the fungicide market restrictions. Developing markets such as China, India, and South Korea will see good growth in the fungicide market over the next decade as a result of continued agricultural intensification and the use of highly effective, low-cost fungicide products.

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