N, P and K fertilizers improved mulberry leaf, stem and fruit yields on peat, the optimum rates being 100 kg/ha/yr N, 25 kg P and 62·5 kg K, with further leaf responses to N and K if applied together in the ratio of 3:2. Harvesting every 2 months at 60 cm height gave better yearly leaf yields than cuttings 3–12 months apart, but annual stem yields were not affected by harvesting frequency and fruit yields were optimum when plants were cut at intervals of 5–6 months. Harvesting quarterly at 60 cm produced better leaf and stem yields than cutting lower (15 and 30 cm) or higher (100 and 180 cm). Two Thai cvs (Noi I and Mii) were female-sterile but the Local Malaysian produced fruits.