Natural fibres used for making twine include wool, cotton, sisal, jute, hemp, henequen, and coir. Grass, rush, hemp, and sisal are all used in making rope. The chief exports include cotton, sugar, chromite, sisal, copra, and hardwood. Scratching posts made of sisal rope or corrugated cardboard are also common. In addition to bark and sisal, hammocks were constructed from various materials, including palm fronds. Coconuts, pineapples, cashew nuts, cotton, sugarcane, sisal, and corn are grown in the lower-lying areas. The main exports are cotton, rubber, timber, coffee, and sisal. Small bundles of sisal fibres of the same length were bundled together. They are designed to penetrate dart boards made of bundled fibers (usually sisal). The fertility of some valleys allows the cultivation of sugar cane, sisal and fruits. Among its major industries were cement, sisal and cashew. Sisal producers established centralized controls for the export of their fibre. Other export crops are pimento, ginger, tobacco, sisal and other fruit are exported. In later years, a summer cloche might be made from sisal or straw. Mboya's father Leonard Ndiege was an overseer at a sisal plantation in Kilima Mbogo.