They warned imports of crops not subject to similar pesticide restrictions would threaten French jobs.
Unions were expecting 500 tractors and 2,000 farmers from around Paris to join the protest. It was too early to confirm the numbers, a spokesperson for the CGB union said.
Tractors, some of which carried banners saying "Macron is liquidating agriculture" and "save your farmer", were scheduled to end their procession in front of the Invalides monument, near France's agriculture ministry.