What term describes chemical burns that can occur to the leaves, flowers, or stems of plants?

The term that describes chemical burns occurring on the leaves, flowers, or stems of plants is phytotoxicity or phytotoxic. Phytotoxicity refers to the harmful effects that certain chemicals, particularly pesticides or herbicides, can have on plants. When a plant is exposed to a substance that it cannot tolerate, the resulting damage can manifest as symptoms such as browning, wilting, or leaf drop, which are characteristic of chemical burns.

Phytotoxicity can occur due to various factors, including incorrect application rates, environmental conditions, or the sensitivity of specific plant species to certain chemicals. Understanding phytotoxicity is essential for ensuring that the application of pesticides does not inadvertently harm desired plants while targeting pests or weeds.

Other terms described in the question, such as pathogenicity, refer to the ability of a pathogen to cause disease in a plant rather than chemical damage. Herbicidal effects would generally refer to the intended outcome of herbicides in controlling unwanted plants, but it does not specifically denote the injurious impact on the treated plants themselves. Foliar burn is a related term but is more descriptive of the visible symptoms rather than the overarching concept of toxicity from chemicals. Hence, phytotoxicity is the most comprehensive term that accurately describes the phenomenon in question