Physiological impacts of pesticides on crop

Abstract Crops undergo many biotic stresses such as the competition with weeds or the attack by various microorganisms, insects, etc. Nowadays, the use of agrochemicals is the main strategy to limit these biotic stresses, but this can generate a dramatic alteration of plant health and a subsequent loss of yield. Pesticides are often used in agriculture to protect human being from the insect vector of disease-causing pathogen to protect crop plant from competition. This chapter intends to discuss about physiological effects of pesticides on different plant viz. legumes, cereals, vegetables, and medicinal plants. Also, uptake, metabolism, and persistence of pesticides are discussed here. It is known that agrochemicals trigger various metabolic pathways of plant defenses enabling crops to recover normal physiology and thus to counteract the effect of chemical treatments. However, the induction of plant defense mechanisms is not always sufficient to maintain an optimal plant growth. Whatever the mode of action of pesticides, their side effects cause a decrease of yield in terms of biomass, fruit/seed quantity, and/or quality.