With the continuous expansion of the planting area of ​​the leeks, during the cultivation process, it is often subjected to serious damage to the disease, which not only results in a serious reduction in production, but also affects the quality and causes great economic losses to the farmers.
Symptoms: After the leaves become infected, they appear as dark green water. The sick department is obviously contracted after dehydration. The leaves are rotted and rotted. When the humidity is high, the diseased part produces sparse white mold; the pseudo-stem suffers from flooding and light brown rot. The leaf sheath is easy to fall off, and when the humidity is high, white sparse mold layer grows on it. The bulbs were damaged, the root disk was water-soaked, brownish to dark brown rot, and the light bulbs inside the longitudinal bulbs were light brown, affecting the nutrient storage of the plants, the growth was inhibited, the new leaves were delicate, the roots were damaged, browning was rotted, and the root hairs were reduced. Very few new roots were issued and the growth was significantly weakened.
The pathogen is Phytophthora nicotianae, a pathogenic fungus of the flagellin subdivision Oomycetes. The bacteria produce tiny sporangia, oospores, chlamydospore, and other propagules that are invisible to the naked eye, but most sporangia accumulate together to form a macroscopic gray mold layer, which is an important diagnostic feature. In addition to leeks and other allium vegetables, it can also harm tobacco, solanaceous vegetables and a variety of fruit trees.
The characteristics of the disease: pathogenic bacteria in the overwintering disease strains or overwintering with the diseased body in the soil. The germs are re-infected by means of irrigation water, rainwater, airflow, and agricultural operations. The optimum temperature for disease occurrence is 26 to 32 degrees, and high humidity is conducive to disease. The soil moisture content is large and the air humidity is heavy. Especially in greenhouses and other protective cultivation environment, if you do not pay attention to ventilation and dehydration, often more exposed to more easily induced damage and more serious damage, greenhouse leakage is often easy to form the center of the disease. Poor management of fertilizers and water, especially the application of nitrogenous fertilizers or planted land, etc. will aggravate the disease.
Control methods:
1. Change crops to avoid planting for consecutive years.
2. Field management: Small water ground irrigation is used to spread water through the water, so if the water is flooded, the water absorption capacity of the roots is weak, and the indoor humidity is too high and the disease occurs. Rational fertilization based on the application of basic fertilizer (organic fertilizer), pay attention to nitrogen, phosphorus and potassium combined application. Disposal of sick and sick bodies is the main cause of the spread of leek disease. Therefore, when the leaves are sick and dry, they should be removed in time and brought out of the house to reduce the source of bacteria. Strengthen the management of leeks in the growth process, such as indoor humidity is too high, the temperature is too high, the choice of sunny and windless, set off at noon plastic film leeward about 3 hours to reduce the indoor temperature and humidity. Note that if transplanting is used, 5000–7500 kg of farmyard manure will be applied before transplanting, and watering and topdressing shall be timely after planting, and top dressing shall be applied 1~2 times after each harvest. Plants more than 3 years old need to be well-rooted and cultivated to prevent leggy and lodging.
3, the drug prevention and treatment of early onset of spraying. If the disease is severe, spray once every 10 to 15 days and spray 2 to 3 times. 72.2% Prokaryl 600 times liquid, 72% DuPont Kelu wettable powder 700 times, 50% dilute morpholine wettable powder 1500 times, 72% metalaxyl manganese zinc 500 times, etc. can be used for spraying. Once every 7 days or so, spraying 2 or 3 times can effectively control the spread of the disease.
Plant extracts refers to substances extracted or processed from plants (all or part of plants) with appropriate solvents or methods. They can be used in pharmaceutical industry, food industry, daily chemical industry and other industries.
There is a conceptual intersection between plant extracts and Chinese herbal extracts. The raw materials of plant extracts in China mainly come from Chinese herbal medicine. Therefore, domestic plant extracts can also be called traditional Chinese medicine extracts to some extent. They are generally included in the category of traditional Chinese medicine products in China's export trade statistics.
Development History
China's plant extracts come from the traditional Chinese medicine industry, and the overall development time is relatively late. In the 1970s, some Chinese herbal medicine factories began to use mechanical equipment to extract active ingredients, but only as part of production, plant extracts have not been produced on a large scale. Until the 1990s, the international trend of returning to nature rose, and people began to tend to use natural plant products. During this period, China's foreign trade rose, and China's Plant Extract industry was getting better and better. In the 21st century, with the application of more advanced extraction methods such as enzymatic extraction, ultrasound, supercritical extraction, membrane separation technology and microwave extraction technology, the yield of extract has been greatly improved, and China's plant extract industry has entered a golden period of development. From 2010 to 2015, the production capacity and export volume of plant extracts increased steadily and rapidly every year, and the proportion of plant extracts in the export of traditional Chinese medicine also increased a lot. Since 2016, the market situation of plant extracts has changed.
Classification
1. According to the content of active ingredients, it can be divided into three categories: effective monomer extract, standard extract and ratio extract;
2. It is divided into glycosides, acids, polyphenols, polysaccharides, terpenes, flavonoids, alkaloids, etc;
3. According to the product form, it can be divided into vegetable oil, extract, powder, lens, etc.
4. According to the purpose, plant extracts can be divided into natural pigment products, traditional Chinese medicine extract products, extract products and concentrated products.
Application
The application scope of plant extracts has been very wide nowadays. In addition to traditional Chinese medicine products, with the gradual increase of people's trust and dependence on natural products, a large part of plant extracts have been used in health products and food ingredients. In addition, plant extracts have been used in cosmetics and feed in recent years.
Some of the best-selling plant extracts in the world have several classifications. For example, Rhodiola, ginkgo, ginseng extract, etc. are used in the fields of brain strengthening, intelligence, prevention and treatment of Alzheimer's disease; Green tea, Fructus aurantii Immaturus, apple and bitter melon polypeptide extract are applied to reduce weight, reduce blood sugar and prevent diabetes. Paclitaxel, tea polyphenols, theanine, bioflavonoids such as lycopene and Anthocyanin are used in the field of natural anti-cancer; Licorice, garlic, Astragalus membranaceus and soybean extracts are used in the field of human immune system.
Ashwaganda Root Extract, ,Sophora Japonica Extract, Hypericum Perforatum Extract, Salvia Miltiorrhiza Extract
Xi'an Tian Guangyuan Biotech Co., Ltd. , https://www.tgybiotech.com