What plant disease is characterized by reddish to brown lesions often surrounded by a yellow halo?

The disease characterized by reddish to brown lesions often surrounded by a yellow halo is anthracnose. This fungal disease affects a wide variety of plants, and the symptoms typically manifest as spots or lesions that can be brown or reddish in color, with a distinct yellow halo which indicates the tissue damage caused by the infection. The appearance of the yellow halo is a crucial diagnostic feature, as it reflects the plant's response to the pathogen and helps differentiate anthracnose from similar diseases.

In contrast, brown patch disease primarily affects turfgrass and is known for causing large, circular patches of dead grass rather than distinct lesions with halos. Root-knot disease is caused by nematodes and leads to root galls or knots, impacting the overall health of the plant but not producing the lesion type described in the question. Powdery mildew is a fungal disease that typically presents as a white, powdery fungal growth on leaves, which is also quite distinct from the reddish to brown lesions highlighted in the case of anthracnose.