How to Choose Fungicides Correctly
Carbendazim pesticide is a popular systemic fungicide and can deal with dozens of fungus diseases. It has powerful potency against ascomycetes and fungi imperfecti, but not valid towards the diseases caused by oomycetes in germ and fungus. As a result, after diagnosing that the plant is infected by fungus and repetitive uses of carbendazim is futile, you should consider changing into phenyl group amides pesticide(For example, metalaxyl). This kind of pesticide is mainly used in downy mildew, phytophthora disease, and pythium disease caused by oomycetes, but does not work well to other diseases caused by fungus and germ. This is why metalaxyl is the first option in the prevention and treatment of phytophthora nicotianae other than carbendazim.
Copper adipate (DT) combines the advantages of carbendazim and metalaxyl, not only works well in preventing and dealing with fungi imperfecti, ascomycetes, and oomycetes, but also germ resistant to some degree. Copper adipate is the recommended choice when the flower growers diagnosed that the plant is infected by both fungus and germ.
Diniconazole is also named Subaoli in Chinese, and has special functions in dealing with powdery mildew, rust disease, smut disease, and scab. It proves to be effective in root diseases caused by rhizoctonia and sclerotinia sclerotiorum.
Chlorothalonil is a kind of non-systemic broad spectrum fungicide with preventing effects on several kinds of plant fungal disease. It can prevent spores of the germs from sprouting, inhibit the hypha development, and the formation of spore. It can also prevent and treat the disease that is resistant to carbendazim, but does not work well in dealing with the diseases caused by soil-borne pythium. In the prevention and treatment of soil-borne diseases, fenaminosulf is effective in dealing with diseases caused by pythium and aphanomyces germ. Therefore, mix quintozene and fenaminosulf with the ratio of 3:1, apply 4 to 8 kg every 667 square meters and mix with fine earth with the ratio of 1:200, furrow application. Seedling damping off infection caused by rhizoctonia, fusarium, and pythium can be prevented and cured.