HORTICULTURE

Plant Disease

Any condition caused by living or non-living agents that interferes with a plant's normal growth and development.

Great Famine in Ireland

A historical event in the 1840s caused by late potato blight disease, leading to significant deaths and emigration.

Boll Weevil

Insect infestation around 1915 that devastated cotton crops, resulting in the migration of sharecroppers.

Chestnut Blight

Introduction of the nonnative fungus Cryphonectria parasitica that infected chestnut trees, almost eliminating the American chestnut.

Dutch Elm Disease

Caused by the fungus Ophiostoma ulmi, leading to the devastation of American elm trees.

Biotic Agents

Living factors causing plant diseases, including fungi, bacteria, phytoplasmas, nematodes, viruses, or viroids.

Abiotic Agents

Non-living factors causing plant diseases, including environmental and cultural factors.

Leaf Spot

Dead, discolored, or injured areas on plant tissue with distinct margins, often seen on leaves or fruit.

Blight

Rapid yellowing, browning, collapse, and death of leaves, shoots, stems, flowers, or the entire plant.

Chlorosis

Yellowing of leaves and stems that are normally green, indicating a plant disease.