Diversified agriculture is a growing sector of the economy. Major crops include macadamia nuts, papaya, flowers, tropical and temperate vegetables, and coffee beans. Only coffee grown in the Kona District of this island may be branded Kona coffee. The island's orchid agriculture is the largest in the state, and resulted in the unofficial nickname The Orchid Isle. The island is home to one of the United States' largest cattle ranches: Parker Ranch, on in Waimea. The island is also known for astronomy, with numerous telescopes operated on the summit of Mauna Kea, where atmospheric clarity is excellent and there is little light pollution.