Is it permissible to pick grapes in France in September?

If a Muslim is certain or strongly presumes that the person harvesting or selling grapes to him will use them to make wine, then it is not permissible for him to do so, as this constitutes cooperation in sin and aggression, which Allah has forbidden, saying: "And cooperate not in sin and aggression. And fear Allah; indeed, Allah is severe in penalty." The sale of anything is prohibited if it is known that the buyer intends to use it for an impermissible purpose, such as selling grapes to someone who will press them into wine.