Each Fall farmers and gardeners alike reap the fruits of their labors. It is busy time of the year and if anything goes wrong with the harvest, an entire crop can be wasted.
It is most appropriate to pray to God for a successful Fall harvest, asking him to accompany all farmers and gardeners, that they may be able to reap a bountiful reward.
Here is a prayer from the book Blessed Be God: A Complete Catholic Prayer Book by Charles J. Callan.
O Lord, graciously look down upon Thy servants and upon the work of their hands, and do Thou, Who givest food to every creature, bless and preserve the fruits of the earth, that the needy may be filled with good things and that all may praise the glory of Thy bounty. Through Christ our Lord. Amen.