Ecotoxicological effects of insecticides in plants assessed by germination and other phytotoxicity tools

Abstract

The management of crop-pests relies largely on conventional insecticides. Farmers around the world use pesticides as an insurance policy against the possibility of a devastating crop loss from pests and diseases. Conversely, the use of insecticides has several drawbacks for agriculture, such as decrease in pollinator population and terrestrial pollution as they are frequently detected in the environment. Several tests are used to assess phytotoxicity regarding several mechanisms affecting plants, namely, (a) inhibition of biological processes such as photosynthesis, cell division, enzyme function, and root, shoot, and leaf development; (b) interference with the synthesis of pigments, proteins, or DNA; (c) cell membrane instability; and (d) the promotion of uncontrolled growth. Germination tests are extensively used to assess the toxicity induced by pollutants. In these types of tests, the germination indexes and the seedling's growth and development are evaluated in a dose-response manner. This review evaluates the application of insecticides leading to alteration on germination, in biochemical, physiological, and different enzymatic and nonenzymatic antioxidant levels that may affect the crop yield and insecticide residues in plants. As such, this chapter represents a systematic and integrated picture of insecticide toxicological effects on plants, highlighting germination.