... irreplaceable in the cropping systems. • Sweet potato is planted in as a spring crop in Quangtri, mainly as a winter crop in Thanhhoa and as a winter and spring crop in Bacgiang. • Farmers in all investigated ... wanted to get help in cultivation technique training, food processing, storage, the maintenance of planting material training. In Bacgiang province, 67-100% of farmers needed to get help in these ... irreplaceable in the crop systems. • Sweet potato was planted in 3 growth seasons, winter, winter - spring and spring crops. In Quangtri province, sweet potato was mainly cultivated as the winter-spring...