Sheltered cucumber disease prevention and control

Sheltered Cucumber Disease Prevention and Control The variety of cucumber diseases in the greenhouse is large, spreads rapidly, and the damage is serious and difficult to control. However, we have obtained some practical and effective experiences through a three-year comprehensive protection experiment against cucumber diseases in greenhouses. The specific requirement is to strictly control the "five customs." The first is that seed treatment is the main source of disease infestation and must be disinfected. To prevent cucumber yellow leaf disease, use 10% sodium phosphate solution to soak in water for 20 minutes; prevent cucumber anthracnose, disease, etc., soak in seeds in 1% formalin solution for 30 minutes, and wash and dry after dipping. Or pre-soaked with cold water for 4 to 6 hours, then immersed in warm water of 49 to 50°C for 1 minute, and then placed in 55°C constant temperature water for 5 to 7 minutes. To prevent bacterial blight of cucumber, use 40% sodium chloride 20 times liquid soaking for 20-30 minutes, or use 70% calcium chloride 300-500 times liquid soaking for 30-60 minutes. After immersion, rinse with water. It should be noted that: soaking the seeds with a solution of about 5 to 10 centimeters is preferable for immersing seeds, and do not stir during soaking, so as not to affect the suffocation effect. The second is the high humidity environment in the greenhouse, which is the main factor for high incidence of cucumber downy mildew and other diseases, so reduce the humidity within the greenhouse, maintain the air humidity in the greenhouse under 83% for about 4 hours, can effectively control the downy mildew Disease occurs. There are two methods for preventing moisture: artificial ventilation and blowing “dry hot air”. The third is high temperature stuffy shed when the shed temperature is between 20 ~ 30 °C, it is easy to cause cucumber downy mildew, anthrax, sclerotinia and other pathogenic diseases, so artificially control the temperature inside the shed A certain range above 30 °C, and maintain for a period of time, can effectively inhibit the spread of the above diseases. The method is: about 40 days after transplanting, close the greenhouse door and side tuyere measures, every 1 to 3 days for a high temperature stuffy shed, the time is generally around noon, the maximum temperature within the shed is controlled at 40 ~ 47 °C, and For about 2 hours, the temperature above 42°C should be maintained for at least 1.5 hours, and the temperature above 45°C should be maintained for more than 1 hour. Fourth, the smoke prevention and control of the disease through the actual application shows that with Bacillus Qing as the main ingredient of the fumigation agent - a smoked Ling, greenhouse fungal diseases such as downy mildew, powdery mildew, anthrax, etc., control effect can be Up to 82% to 100%. Technical points: It is usually done in the evening, once every 12 to 16 days, 3 to 4 consecutive times. Each space of 30 meters in length, 6 meters in width, and 2.5 meters in height is required. In the shed, evenly suspended with 30 grams of a smoked spirit with aluminum wire, 4 or so smokers are ignited from inside to outside, and they leave the shed and immediately shut down. All doors and side vents are sealed to prevent smoke from seeping. The next day you can work in the shed. The fifth is spray disease prevention In general, cucumber wilt disease, powdery mildew, downy mildew disease, the incidence of the beginning with 3% agricultural resistance 120, Mushi 75 kg 200 times liquid, sprayed every 6 days, continuous 2 ~ 3 times, or 90% of aluminum diphosphorus 700 times, or 58% of toxic manganese zinc spray 800 to 1000 times, have a higher control effect on cucumber diseases.

Polysaccharides are polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic linkages, and on hydrolysis give the constituent monosaccharides or oligosaccharides. They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch and glycogen, and structural polysaccharides such as cellulose and chitin.

Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure, these macromolecules can have distinct properties from their monosaccharide building blocks. They may be amorphous or even insoluble in water. When all the monosaccharides in a polysaccharide are the same type, the polysaccharide is called a homopolysaccharide or homoglycan, but when more than one type of monosaccharide is present they are called heteropolysaccharides or heteroglycans.

Natural saccharides are generally of simple carbohydrates called monosaccharides with general formula (CH2O)n where n is three or more. Examples of monosaccharides are glucose, fructose, and glyceraldehyde. Polysaccharides, meanwhile, have a general formula of Cx(H2O)y where x is usually a large number between 200 and 2500. When the repeating units in the polymer backbone are six-carbon monosaccharides, as is often the case, the general formula simplifies to (C6H10O5)n, where typically 40≤n≤3000.

As a rule of thumb, polysaccharides contain more than ten monosaccharide units, whereas oligosaccharides contain three to ten monosaccharide units; but the precise cutoff varies somewhat according to convention. Polysaccharides are an important class of biological polymers. Their function in living organisms is usually either structure- or storage-related. Starch (a polymer of glucose) is used as a storage polysaccharide in plants, being found in the form of both amylose and the branched amylopectin. In animals, the structurally similar glucose polymer is the more densely branched glycogen, sometimes called "animal starch". Glycogen's properties allow it to be metabolized more quickly, which suits the active lives of moving animals.

Cellulose and chitin are examples of structural polysaccharides. Cellulose is used in the cell walls of plants and other organisms, and is said to be the most abundant organic molecule on Earth.It has many uses such as a significant role in the paper and textile industries, and is used as a feedstock for the production of rayon (via the viscose process), cellulose acetate, celluloid, and nitrocellulose. Chitin has a similar structure, but has nitrogen-containing side branches, increasing its strength. It is found in arthropod exoskeletons and in the cell walls of some fungi. It also has multiple uses, including surgical threads. Polysaccharides also include callose or laminarin, chrysolaminarin, xylan, arabinoxylan, mannan, fucoidan and galactomannan.

Polysaccharide Series

Polysaccharide Series,Cordyceps Polysaccharide,Hericium Erinaceus Polysaccharide,Goji Polysaccharide

Excellent Health Products Co.,Ltd. , http://www.sino-excellent.com