Incorporate well into the soil. Form trenches by digging about 250mm wide by 150-250mm deep and 60cm apart. Add a little old manure or ready compost on the bottom of the trenches to aid fertility. Incorporate these evenly throughout the soil. Irrigate a dry soil before planting and avoid watering until sprouts have emerged.
Seed is more prone to disease.
Irrigate when soil feels dry a few inches below the surface. Do not let plants dry out especially when tubers are forming during the second month. Once flowering begins ease back on the water but still keep plants moist. You may like to apply a fish emulsion, nitrogen source, after plant emergence and before flowering. As the plants grow they require hilling with extra soil.