Complex sentence: Upon his return, he gave the trees to ex-West Indies settler and agriculturalist, John Wilkinson, to plant on the Chief's land in Oahu's Manoa Valley, but was never able to cultivate the trees for fruit production.
Split into simpler sentences: Upon his return, he gave the trees to ex-West Indies settler and agriculturalist, John Wilkinson, to plant on the Chief's land in Manoa Valley on Oahu. He was never able to cultivate the trees for fruit production.