A farmer; one who cultivates or tills the ground. In this verse, Jesus likens God, The Father, to a farmer or Master Gardener; Himself to the Vine; us, to the branches of the Vine; and the fruit we bear is the Fruit of the Spirit.

I am the true Vine, and my Father is the husbandman. Every branch in me that beareth not fruit He taketh away: and every branch that beareth fruit, He purgeth it, that it may bring forth more fruit. Now ye are clean through the word which I have spoken unto you.
John 15:1-3

But the Fruit of the Spirit is love, joy, peace, long-suffering, gentleness, goodness, faith, meekness, and temperance. Against such there is no law.
Galatians 5:22