Of course I do. Farming is a huge contributor to Russia's export economy, which is what funds their invasion of Ukraine, along with other aggression from them.

It would be perfectly valid for Ukraine to attack Russian farming infrastructure and farmers themselves. The better strategy is probably to stick to attacking infrastructure only, for PR reasons, and that is exactly what Ukraine has done so far. But it is ethical to attack both in this circumstance.

In WW2 it was reasonably common for returning allied fighters with spare ammo to strafe German farmers in their fields on the way home. I've seen the gun cam footage of them doing it. That was a perfectly valid strategy, and helped end the war sooner: towards the end Germany was starving, including the soldiers.