Which of the following accurately describes the management strategies for protecting against corn smut?

Managing corn smut, a fungal pathogen caused by Ustilago maydis, requires strategic approaches to minimize its impact on corn production. Avoiding physical injury to crops is crucial because the fungus can enter the plant through wounds or lesions. When plants are physically damaged, whether from mechanical actions like cultivation or from pest activities, it increases the likelihood that the pathogenic spores will infect the plant. Keeping plants healthy and free from injury helps to maintain their resilience against diseases, including corn smut.

In contrast, increasing nitrogen fertilization can actually promote the growth of foliage and, ultimately, the conditions that favor the development of corn smut. Planting only susceptible cultivars would only heighten the risk of infection since these plants lack genetic resistance to the disease. Additionally, reduced crop rotation can lead to the build-up of soil-borne pathogens like corn smut, as rotating crops helps break the life cycle of such diseases. Hence, protecting crops through minimizing physical injuries aligns with effective disease management practices.