Xiaozhang Town, Zaoqiang County, Hengshui is located in the alluvial plain in the middle of the Heilonggang Basin. It has flat terrain, deep soil, and nearly 10,000 acres of sandy river land, making it the best location for growing sweet potatoes. At present, a virus-free sweet potato promotion demonstration base in Hebei Province has been built with Dongfang Village as the center and radiating to 8 surrounding villages. It has developed virus-free sweet potatoes "Beijing 553", "Taishu No. 2", "Jishu No. 4" and other planting areas of 6,000 There are more than one mu, with an average yield of 6,000 kilograms per mu. Registered trademark "Dongfang" brand.

Virus-free sweet potato is a product of the combination of biotechnology and virology technology. According to the characteristics and rules of the movement and distribution of viruses in plants, biotechnological measures are taken to remove the viruses. The detoxified sweet potato has a smooth, uniform shape and a sweet taste. Contains protein, fat, carbohydrates, crude fiber, carotene, thiamine, riboflavin, niacin, ascorbic acid, ash, calcium, phosphorus and iron. It can nourish the spleen and qi, produce body fluids and quench thirst, and widen the intestines to relieve constipation. , has the effects of anti-cancer, preventing cancer, reducing plasma cholesterol levels, preventing arteriosclerosis, anti-aging, protecting eyesight, and improving human immunity. Therefore, the medical community ranks it as the first anti-cancer fruit and vegetable, and nutritionists call it a "longevity food".