Southern Corn Rust
About the Disease: this is a fungal disease that is characterized by the formation of blights on the leaf. This is different from the leaf spot disease. There are so many types of sweet corn diseases. Some are caused by the fungi, while some are caused by the bacteria. There are even other diseases, where virus plays an important role. The main cause for the rust in corn is due to the fungus Puccinia.
Symptoms: Normally, in the common corn rust, you can find the presence of pustules and discoloration or yellowing of the leaf on both the upper surface as well as the lower surface. But in the case of Southern rust in corns, you cannot find many pustules on the lower surface of the foliage in corn. These pustules are mainly found in the upper portion of the leaf surface.
Normally the pustules will be bright red or bright brown in color in many of the plant. But if a plant gets affected by the Southern rust, then it surely shows pustules that are orange in color. This is one of the most unique features of this plant disease. When you compare the pustules formed in the diseases like common rust and the southern rust, you can find that they take more time to enter into the leaf epidermis in Southern rust disease than the common rust disease.
Pathogen Involved: In the case of Southern corn rust, it is caused by the Puccinia polysora. Many pustules will be formed in the leaves. Once it breaks, it releases the spores of fungus.
Time of Occurrence: It mainly occurs in the humid weather.
Conditions Favoring Disease: The best condition that is needed for the fungi to live and spoil the plants, is a temperature of 80 degrees in Fahrenheit. High humidity also helps in the fungal growth. Air is needed to disperse the fungal spores to different corn plants.
Disease Management: the fungicides must always be readily available in hand, if you are growing a lot of corns in your field. If you do not have the habit of practicing crop rotation, then you might have to suffer a heavy loss on your cultivation. It is wise to choose the hybrid and resistant varieties than growing the normal corn crops. It is not possible to control the climatic condition but you can surely control the variety of crops grown. Along with this corn, some non grass crops can also be grown.