Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others. The most common of these are herbicides, which account for approximately 50% of all pesticide use globally. Most pesticides are used as plant protection products, which in general protect plants from weeds, fungi, or insects. In general, a pesticide is a chemical or biological agent that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, or spread disease, or are disease vectors. Along with these benefits, pesticides also have drawbacks, such as potential toxicity to humans and other species.

कीटनाशक Archived 2023-01-06 at the वेबैक मशीन रासायनिक या जैविक पदार्थों का ऐसा मिश्रण होता है जो कीड़े मकोड़ों से होनेवाले दुष्प्रभावों को कम करने, उन्हें मारने या उनसे बचाने के लिए किया जाता है। इसका प्रयोग कृषि के क्षेत्र में पेड़ पौधों को बचाने के लिए बहुतायत से किया जाता है।