southern corn rust dataset|玉米病害数据集|农业科学数据集

Southern rust of maize. Southern corn rust is one of the most common diseases in tropical and subtropical corn growing areas. Fast epidemic speed has a serious impact on yield. It is more dangerous than common corn rust. The pathogen of the disease overwinters in the winter corn growing areas along the southern coast. During a growing season, summer spores spread from south to north along with warm and humid air flow over a long distance. Hainan and Taiwan provinces in China are distributed, but in recent years, large-scale occurrence has occurred in some parts of the north, with a trend of spreading northward. The pathogen produces summer spores, which spread with the wind and rain, and is harmful to rolling. The pathogen can not live without the host plant for a long time. Symptoms are similar to those of common rust, but the color of summer spore heap of common rust is rust yellow, and that of summer spore heap of Southern rust is orange yellow. After the pathogen infects, the small green spots on the leaves become yellowish-brown protuberant blisters, i.e. the summer spore heap of the pathogen. Different from the common rust, the main symptoms of summer spores are that summer spores pile up on the front of leaves, which are abundant and densely distributed, and rarely on the back of leaves. Sometimes a small amount of summer spore piles appeared on the back of leaves, but only in the midrib and its vicinity. Summer spores are round and oval, smaller and lighter in color than those of common rust. The dehiscence of the epidermis covering the summer spore heap was slow but not obvious. In the late stage of onset, the winter spore heap was scattered near the summer spore heap. Winter spore heaps are dark brown to black, often with dark halos around them. The epidermis of the winter spore heap does not break. [Control methods]. [Planting disease-resistant varieties] The resistance of different maize varieties to rust is quite different, and using disease-resistant varieties is an effective way to control maize rust. [Scientific field management] timely sowing; appropriate reduction of nitrogen fertilizer, increased application of phosphorus and potassium fertilizer, timely spraying of foliar nutrients to improve disease resistance of maize plants; rational control of density, improve permeability. Early removal of plant debris in and around the field before planting, if found in the growing period should be timely pulled out and centralized destruction, maize harvest should also be timely removal of residual plants, stems and leaves, centralized burning or fertilization. Rotation and non-gramineous crop rotation can reduce the accumulation of pathogens. For sporadic maize, the diseased plants and residual disease bodies should be pulled out at any time. [Scientific field management] timely sowing; appropriate reduction of nitrogen fertilizer, increased application of phosphorus and potassium fertilizer, timely spraying of foliar nutrients to improve disease resistance of maize plants; rational control of density, improve permeability. Early removal of plant debris in and around the field before planting, if found in the growing period should be timely pulled out and centralized destruction, maize harvest should also be timely removal of residual plants, stems and leaves, centralized burning or fertilization. Rotation and non-gramineous crop rotation can reduce the accumulation of pathogens. For sporadic maize, the diseased plants and residual disease bodies should be pulled out at any time. [Pharmaceutical control, prevention mainly] Spraying agents containing difenoconazole, tebuconazole, triazolone, propiconazole, pyrimethyl ester, ethermycin ester and pyrazole ether ester can effectively alleviate the occurrence of Southern rust in late stage of maize trumpet-silking. Prevention plan: in order to prevent the occurrence of Southern rust, farmers can use 25% powder, 20%, three zolone pesticide spray control. If there is no prevention in the early stage, spraying in the early stage of rust can also control the incidence of rust and reduce the impact on production to a certain extent.