Corn diseasescan cause discoloration and deformation of leaves, drying out of whole plants, and damage the cobs, which significantly reduces the quality and quantity of the harvested crop. The most frequently observed disease symptoms arecorn stains and curlingSee how to recognize individual corn diseases and how to prevent them.
Corn diseases: (1) corn rust, (2) yellow leaf spot
Corn rust
Ifcorn leaves are curled and blotchyit may be a sign of a fungal disease such as corn rust. This disease is caused by the fungus Puccinia sorghi. The development of the disease is favored by warm weather, little rainfall, dew and high air humidity. Corn rust also promotes the weakening of the plant by feeding aphids. The firstsymptoms of maize rustare visible on the lower leaves at the end of June, July and August.
The source of infection are spores that hibernate on crop debris. They thrive on sorrel, which is the spring intermediate host. From it, the wind transfers the spores to the corn. Maize rust can also thrive without an intermediate host, and spores from crop residues can be transferred to other maize plants.
Pillows about 1 mm in diameter appear on the leaves , which burst and release spores in the form of gray-brown powder.The spores are then carried by wind and rain and infect he althy plants.Corn leaves curl and dry from the edgesUnder favorable conditions, the symptoms of this maize disease spread to all above-ground, green plant organs, which may cause the maize to mature prematurely and our yield will be lower.
Corn leaf spot
Corn fine leaf spot is also calledcorn anthracnoseSymptoms of this corn disease can be seen on the leaves. The Kabatiella zeae pathogen affects the leaves as well as the vaginas and cobs. The first symptoms are visible in the form of small bright, translucent points. Later,oily spots appear on the corn leavesThen the cream-colored center of the spot dries out and the light brown ring turns reddish brown. If there are many spots, they merge with each other and can cover a significant part of the surface of the leaf blade, vagina and cobs.
PrimaryCorn leaves may be infected in June or JulyThis disease of maize is favored by weather conditions (wet and cool summer) and leaf damage caused by aphid feeding. If the disease occurs early and with high intensity, unfortunately, we can expect a much lower yield.
Corn Leaf Yellow Spot
Another disease of corn is yellow leaf spot. The source of the infection is the fungus Exserohilum turcicum hibernating on crop residues and on seed in the form of mycelium and spores. The disease is favored by wind, rainy weather and aphid feeding. The firstsymptoms of corn leaf spot yelloware visible on the lower leaves, then the middle leaves, and then the cobs cover leaves.Corn leaf spots are watery, gray-green, later gray-brown with a dark borderCorn leaves may curl when the disease is heavily overgrown with the plant, causing the leaf blades to crack and dry.
Fighting corn diseases
Checking the list of current plant protection products that can be used in the cultivation of maize, unfortunately, we will not find fungicides intended for use in amateur cultivation in gardens. Therefore, the only thing left for us is prophylaxis.
Prevention of corn disease :
- Remember tochoose corn varieties resistant to diseasesand pests, e.g. 'Gucio F1'.
- It is good totreat corn seedsbefore sowing. The T75 DS / WS seed dressing is recommended.
- Useoptimal fertilization . Too high doses of nitrogen fertilizer increase the likelihood of maize diseases.
- In the cultivation of maize,should include alternation , cultivate maize in the same field at intervals of several years.
- It is also importantregular weeding of maizeas fungi can develop on many weed species.
- After the maize harvest is finished, the straw should be cut low and cut into small pieces.Crop remains should be dug deep .
MSc Eng. Joanna Białowąs
