The synthetic auxins are not treated as phytohormones, but they are considered 'plant growth regulators. Many synthetic auxins, such as 2,4−D(2,4− dichlorophenoxy acetic acid), 2,4,5−T(2,4,5 -trichlorophenoxyacetic acid), MCPA (2-methyl-4-chlorophenoxyacetic acid), etc. are used as selective herbicides (i.e. eradicants of weeds). They are widely used as potent defoliants due to their destructive properties.