Effects of sowing dates, population, fertilizer, weeding and variety inputs on yield were measured, as well as labour required to apply the inputs. Sowing date was the most important, response to others being dependent upon this factor. Population was least important, but increased in value as fertilizer level was raised. Labour requirements were so increased by applying the ‘package’ that subsistence farmers, whose families are fully occupied as the sole source of labour, would be unable to cope without reducing the area under cultivation. Thus yield response to a package must be higher than hitherto considered acceptable, and the risk of not obtaining this increase probably contributes to the rejection of such recommendations by subsistence farmers.