With avoiding tar spot you protect the maize harvest from burning.
Tar spot is a fungi, that causes big harvest losses of corn. You can recognize it, because of small black dots on top of the leaves. Around the black dots there are lighter spots in form off a fish eye. If the disease continues, the whole leave gets burned. The burning starts at the bottom of the plant and continues upwards. Tar spot can cause that the kernels rot and if the damage is really big, the grain germinates prematurely. The fungi attacks the plants when the ears are small until the grains are developed. This happens about 30 to 50 days after the plants were planted. The younger the plant is, the stronger it can be attacked.
Cooled and humid weather
The disease spreads in cool temperatures. The air is moist during the night and the early morning. The tar spot is causing damages from year to year, if the remains of attacked maize stay in the field.
Controlling tar spot
If you had tar spots in the previous year, it is best to burn the remains of the last crop. In some areas you can start planting maize early, to avoid tar spot. To avoid that the tar spots spread over the ground, you shouldn‘t plant the maize in the same field every year. Also plant another crop like beans or mucuna. Use local varieties or varieties which are more resistent against the fungi. If the disease appears, but the leaves are still healthy, you can spray a fungicide. Start spraying the fungicide as soon as you see the first little black dots. When the leaves are already burned, the fungicide has no effect anymore.
