The relationship of stem and seed yields to flowering phenology and sex expression in monoecious hemp (Cannabis sativa L.)

► Flowering phenology, sex expression and yields were determined in monoecious hemp. ► Sex expression varied significantly among cultivars. ► Stem yield varied with earliness and seed yield with sex expression and earliness. ► Both yields correlated best with duration sowing-full female or sowing-end of male flowering. ► Producing both stem and seed required early sowing and feminized (mid-) early cultivars.