Summer corn will soon be pollinated after it enters August. The main diseases and insect pests that occur in the middle and late stages of corn include corn top rot, brown spot, stalk rot, corn borer (borerworm), cotton bollworm, armyworm, and corn aphids. 1. Symptoms of major corn diseases 1. Corn brown spot In recent years, the disease often occurs newly. It usually starts when there are 8-10 leaves of corn. The initial stage of the disease is on the lower leaves, sheaths and stems of corn, and it gradually spreads upwards. The lesions are round or oval, brown or reddish-brown, and then enlarged and become brown or purple. The lesions are easy to be densely integrated. The epidermis of the lesions ruptures in the later stage of the disease, and brown powder is emitted. The high temperature and humidity in the middle and late stages of corn are beneficial to this Disease occurs. 2. Corn top rot Corn top rot is the general name of corn top rot disease. The symptoms are diverse. It is a new systemic infectious disease that has emerged in recent years. The main symptoms are: the core and leaves of the injured plant rot from the base of the leaf and are tightly wrapped. In severe cases, the entire heart leaf can be pulled out by hand, and the heart leaf of a mildly ill plant is twisted and cannot be expanded. Some leaves are chlorosis, transparent, brown and rotten, short and incomplete, and some leaves have nicks and yellow streaks on the edges of the leaves, and even wither and die. Pathogenic bacteria generally invade from wounds, stem nodes, heart leaves and other young tissues, especially when they are harmed by thrips, swedish flies, aphids, etc., they will aggravate the occurrence of diseases. High temperature and high humidity are conducive to disease prevalence, which usually occurs after rain or field irrigation. Low-lying or poorly drained plots are more severe. 3. Corn borer (Corn borer) Generally bite the tender leaves in the heart leaf clusters. The damaged leaves show translucent films, cavities, or rows of round holes, mixed with fine insect dung, commonly known as "flower leaves. Corn damages ears, stems, and destroys nutrients. Material transportation seriously affects corn production. 4. Three generations of armyworm Mythimna separata has the characteristics of migratory and localized outbreak hazards, and its occurrence is greatly affected by weather conditions, especially local microclimates. If the armyworm encounters a downdraft during its southward migration, it will cause a large number of adults to fall and cause localized outbreaks and damage. 5. The fourth generation of cotton bollworm The fourth generation of cotton bollworm is a serious pest that damages corn other than the corn borer. The ears of the affected corn have serious mildew (ear rot). It not only aggravates the damage, but also affects the quality. Therefore, the control of cotton bollworm in the later stage is very important. 2. Control technology As the current summer corn planting density is high and the mid- and late-stage plants are already too high, plant protection drones can be fully utilized for the mid- and late-stage corn disease and insect pest control operations to achieve the effects of disease prevention, pest control, stress resistance, and yield increase. "One spray with multiple effects" should focus on the promotion of "prevention technology", and the control time should be after August 15 (after corn pollination). Recommend "one spray with multiple effects" medicine Insecticide: 5% emamectin saline dispersible granules, 25 g/L lambda-cyhalothrin EC, 5% imidacloprid EC, 70% imidacloprid WP, ​​5% acetamiprid EC, 5% chlorantraniliprole Amide suspension agent. Bactericide: 80% tebuconazole wettable powder, 10% difenoconazole EC, 70% thiophanate methyl wettable powder, 25% azoxystrobin suspension. Foliar fertilizer: urea, nitrogen-containing foliar fertilizer, 5% amino oligosaccharide. Disclaimer: Some articles on this website are transferred from the Internet. If the legal rights of a third party are involved, please inform this website for processing. phone Flavored Tea,Lemon Tea,Peach Tea,Ginger Tea DIYAS DEVELOPMENT LIMITED , https://www.diyastea.com
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