Sylvain Quintin can be found on the path east of Rayles Farm, and it's clear that he's in some trouble: he is crouching over his dead horse. You can talk to him about this:
"There's no situation so bad that a dead horse can't make it worse."
"What happened?"
"Well, my horse died, as you might have noticed. A better question would have been, 'How can I help you, good sir?'"
"How can I help you, good sir?"
"Now that you ask, I have a sack of fertilizer here for Skulreid Foxbite of Cropsford. It's no ordinary fertilizer, however. It's so fragrant, it's like having a bag of roses on your shoulder. Would you finish the delivery for me?"
After you agree to finish it, you must travel to Cropsford, which is on the eastern end of Cyrodiil. Skulreid Foxbite can be found tending to his pumpkins. When you tell him you have the fertilizer, he exclaims, "My fertilizer! Silvain's late as usual. But maybe it'll still help my pumpkins. Though that'll just mean more fried pumpkin to eat, I suppose."
