Recently, the Daxing District Plant Protection and Quarantine Station conducted a general survey of the incidence of vegetable pests and found that part of the land was affected by cucumber powdery mildew, and the incidence rate of diseased land was 5%-10%, and the rate of diseased plants in individual severe plots was 80%-90. %, 3-4 functional leaves per plant were susceptible to varying degrees of disease. Cucumber powdery mildew is one of the common diseases in cucumber cultivation. In recent years, because powdery mildew produces certain drug resistance, and it can be affected all year round, it is difficult to control. In general, the annual output is reduced by about 10%. In popular years, the output is reduced by about 20% to 40%. This reminds the vegetable farmer to check in time. Symptoms occur Powdery mildew, commonly known as "white hair," is a common invasive disease of cucumbers in greenhouses and cucumbers in open fields. Any part of the plant can be diseased, with the most severe leaves, followed by petiole and stem, generally not harm the fruit. At the beginning of the disease, white or nearly circular small spots appear on the front or back of the leaves, and they gradually enlarge into large white areas where the edges are not obvious, and are covered with foliage, as if a layer of white powder is scattered. Erasing the white powder shows that the leaves are chlorotic and yellow and brittle. When the disease is severe, the leaves are covered with white powder and turn grayish until the entire leaves die. After powdery mildew infected petiole and tender stems, the symptoms were similar to those on the leaves, but the lesions were smaller and the powder was less. Infestation of flower organs leads to falling flowers. When the weather conditions are poor and the plants age, scattered or piles of dark brown dots appear on the lesions. In addition, the pathogenic bacteria also infect other melon crops and the symptoms are similar to those of cucumbers. Control methods 1. Use resistant varieties. 2. Agricultural measures: Avoid excessive application of nitrogen fertilizer and increase phosphorus and potassium fertilizers. Ventilation and dehumidification in the greenhouse are timely. Implement rotations, strengthen management, and eliminate sick organizations. 3. Chemical control: Facilities disinfection. When growing indoors, use 250 grams of sulfur powder, 500 grams of sawdust, or 250 grams of 45% chlorothalonil smoke agent per 100 cubic meters of space before planting. Light up in several places, seal and fumigate for 1 night to kill the entire shed. Indoor bacteria. Before the onset of the disease, spray 800 times of green milk copper to protect the leaves. In the early stage of disease, use 50% carbendazim WP 800 times or 75% chlorothalonil wettable powder 600-800 times, or 25% triadimefon WP 2000 times, or 50% carbendazim (Cuibei) water dispersed granules 13-20 grams? Mu, or 40% Fuxing 4000-5000 times liquid, or 10% Shigao 1500-2000 times spray control. The key to prevention of powdery mildew is early prevention and reduction of disease sources. The spraying should be thorough, so as to spray the medicine evenly and make the spores of the powdery mildew splinter, but it will not cause downy mildew due to excessive increase of air humidity. The use of various agents alternately prevents the use of a single agent for a long period of time to make the bacteria resistant. Organic stevia extract is a natural sweetener extracted from the pure leaves of the stevia plant. Stevia extract is a natural sweetener and a natural substitute for artificial sweeteners such as aspartame, saccharin, and sucralose. They are all zero-calorie sweeteners, but stevia is a natural source and has no industrial residues.
The main components of stevia extract are stevioside and rebaudioside A. The sweetness is high, and the sweetness is 90-450 times of sucrose / edible sugar. It is ideal for patients with diabetes, hypertension, dental caries, and arteriosclerosis. Stevia Extract,Organic Stevia Sugar,Organic Stevia Extract,Stevia Extract Powder Organicway (xi'an) Food Ingredients Inc. , https://www.organic-powders.com