Читать книгу Plant Pathology and Plant Pathogens - John A. Lucas - Страница 13

Since it is not known whether plants feel pain or discomfort, and since, in any case, plants do not speak or otherwise communicate to us, it is difficult to pinpoint exactly when a plant is diseased.

(George N. Agrios, 1936–2010)

The significance of disease in plants varies depending upon biological, agricultural, and socioeconomic factors. At one extreme, disease may be so severe that the farmer is faced with total crop failure, and the need for control measures is immediately obvious. In other cases, it may be difficult to define disease symptoms, the cause of the problem is not initially clear, and any benefits obtained from control measures are not easy to predict. This chapter discusses the nature of disease and surveys the range of pathogens, pests, and other agents which adversely affect plants. The impact of disease, both in natural plant communities and in agriculture, forestry and horticulture, is then considered.