Introduction to famous and superior sweet potato varieties: these high-quality varieties are worth knowing about

Which sweet potato varieties to choose depends on market demand, what they will be used for, and also the local cultivation ecological conditions, especially soil-borne diseases. According to trials, virus-free cultivation generally increases yield by 20%-30%, and also improves their appearance and marketability. Therefore, choosing virus-free sweet potato elite varieties is the prerequisite for achieving high sweet potato yields. The overall goal is to select virus-free sweet potato varieties that are resistant to disasters and diseases, high-quality, high-yielding and efficient. Based on the national sweet potato regional trials and many years of production practice, the excellent varieties of various types of sweet potato are introduced below for reference in selection.

I. Sweet potatoes for starch processing (or sliced and sun-dried as industrial raw material)

For starch-processing varieties, choose those suited to local conditions with high starch content and starch yield higher than Xushu 18. In disease-free and heavily diseased areas (root rot, stem nematode), choose the nationally approved high-yield, multi-disease-resistant varieties Shangshu 19, Yushu No. 12 and No. 13, and Jishu No. 15 (short vine, drought-resistant, highly resistant to root rot and black spot, relatively resistant to stem nematode); in spring sweet potato areas without root rot, choose high-starch, saccharification-resistant varieties Shang 0110-3, Pingshu No. 3, and high-starch Yushu No. 7, Luo 96-6, Meiying No. 1, etc.; in areas with severe root rot, choose starch-processing varieties such as virus-free Xushu 18 and Jishu 98 (high-yield, high-starch, good overall quality traits).

1. Shangshu 19 (nationally approved high-yield, multi-resistant starch variety)

Advantages: high yield, highly resistant to root rot. Starch content slightly higher than Xu 18, reaching 20-22%. In national northern regional trials, dry tuber and starch yields both exceeded Xushu 18 and selection line 77-6 by more than 10%, ranking first. High-yield spring sweet potato fields yield more than 3,500 kg of fresh tubers per mu, with starch yield reaching about 700 kg per mu. Advantages: high yield, highly resistant to root rot, resistant to stem nematode, drought-resistant, waterlogging-tolerant, excellent overall traits, shorter vines, good sprouting ability.

2. Yushu No. 12 (nationally approved high-yield, multi-resistant starch variety)

Advantages: high yield, waterlogging-tolerant, resistant to root rot, relatively resistant to stem nematode, high starch viscosity, and the vermicelli made from it has strong chewiness. Fresh tuber and starch yields are high, about 20% higher than Xushu 18, with a starch rate of about 20%, equivalent to Xushu 18. National trial results: average fresh tuber yield was 18.6% higher than Xushu 18, average yield increased by 17.1%, and it passed national approval in 2002.

3. Yushu No. 13 (nationally approved multi-resistant, high-yield starch variety)

Advantages: highly resistant to root rot, resistant to stem nematode, drought-resistant, short vines, starch rate 21.9%, close to Xushu 18. National trial results: average fresh tuber yield 13.9% higher than Xushu 18, average dry tuber yield 12.2% higher, and it passed national approval in 2002. Spring sweet potato yield can reach more than 3,500 kg per mu.

4. Pingshu No. 3 (saccharification-resistant, high-yield starch-specific variety)

Advantages: high yield, high starch, saccharification-resistant. In provincial regional trials, dry tuber and starch yields increased by 16.2% and 18.1% respectively compared with Xushu 18 selection 77-6, with an average drying rate of 31.8%, 2.5 percentage points higher than Xushu 18, and a crude starch rate of 22.66%. Characteristics: top leaves green, leaves heart-shaped, veins purple, tuber skin yellow-white, tuber flesh white; when eaten cooked, the taste is mild before and after storage, with little change in dryness and mealiness, showing a very slow saccharification speed. This trait makes it particularly suitable for long-term starch processing, and its yellow-white tuber skin makes it easy to distinguish from other varieties when purchasing fresh tubers for processing. Disadvantages: not disease-resistant. Suitable for planting in disease-free starch-processing areas.

5. Xushu 18 (national trial standard variety)

Bred by the Xuzhou Prefecture Agricultural Science Institute in Jiangsu through sexual hybridization. Advantages: good overall traits, stable yield, highly resistant to root rot, drought-resistant, tolerant of poor soil. Stems and leaves green, leaves heart-shaped with teeth or shallow notches. Veins purple, stems green with purple, medium vines, tuber skin purplish-red, flesh white, cutting-dry rate about 30%, starch rate about 20%, good eating quality, 20-30% higher yield than ordinary Xushu 18, suitable for planting in areas with severe root rot and starch processing. Disadvantages: not resistant to stem nematode or black spot; in stem nematode areas, pay attention to using healthy tubers for seedling raising and drenching roots with 50% phoxim at 1000-1500 times dilution.

6. Yushu No. 7 (nationally approved starch-specific variety)

Advantages: high starch rate, average starch rate as high as 22.61%, spring sweet potato starch rate as high as about 24%, three percentage points higher than Xushu 18; good sprouting ability, good storage tolerance, strong growth vigor, tolerant of poor soil, drought-resistant, and relatively wide adaptability. Dry tuber and starch yields increased by 17.8% and 22.8% respectively compared with Xushu 18. Moderately resistant to stem nematode and black spot. Spring sweet potato yield more than 3,000 kg per mu, summer sweet potato more than 2,000 kg. Disadvantages: not resistant to root rot.

7. Meiying No. 1 (high-starch variety)

Advantages: high starch rate (measured by the Provincial Academy of Agricultural Sciences over two years as 26.07% and 24.8% respectively), drought-resistant, moderately resistant to stem nematode, not resistant to root rot, high spring sweet potato yield. Spring sweet potato starch yield about 20% higher than Xushu 18, and high-yield spring sweet potato fields produce about 3,000 kg of fresh tubers per mu. According to trial plantings in Hubei, Hunan, Shaanxi, Sichuan, Yunnan and other provinces, it shows high starch and high yield. When eaten cooked, the taste is mealy and sweet. After provincial regional trials, this variety is considered suitable for planting in spring sweet potato starch-processing areas without root rot.

II. Sweet potatoes for eating, food processing, or commercial use

For edible varieties, choose those with tuber flesh ranging from yellow to orange-red, smooth skin, good color, early tuber formation, the ability to reach the market early, and both a high commercial tuber rate and high fresh tuber yield, as well as high contents of soluble sugar, carotene, vitamin C and protein. (1) For baking and eating, choose high-quality commercial sweet potatoes: Xu 34, Shang 019-3 (high sugar, high carotene, excellent taste), Lushu No. 8 (light red skin, apricot-yellow flesh, better eating quality than Beijing 553, high yield, drying rate 5 percentage points higher, resistant to root rot and black spot), Beijing 553, Yizi 138, Jishu No. 4, etc. (2) For early market entry as commercial sweet potatoes, choose early-maturing high-yield varieties Xushu 23 (nationally approved variety, relatively high yield, red skin, orange-yellow flesh, high dry matter), Shangshu 85 (Shang 958-5, nationally approved variety, high yield, early-maturing and early to market, red skin red flesh, disease-resistant), Sushu No. 8 and Anping No. 1, also called yellow-skin Su 8. (3) For high-yield, high-quality special-use edible purple sweet potatoes, choose Jishu 18, Guangzi No. 1 (Guang 104, purple skin, mottled purple flesh, excellent taste) and "Qunzi No. 1."

1. High-quality red-flesh variety: Xu 34. Advantages: top-grade eating quality, fine, smooth and sweet; fresh tubers contain 3.09% soluble sugar, 19.39 mg/100 g vitamin C, and 3.93 mg/100 g carotene. Excellent quality for baking and processing into sweet potato preserves. Characteristics: aboveground parts all green, leaves heart-shaped, leaf surface wrinkled, stems and leaves crisp and tender; tubers spindle-shaped, smooth with good appearance; tuber skin ochre-red, tuber flesh orange-red. Tubers form in a concentrated manner and are large and concentrated; summer sweet potato yield about 2,000 kg per mu; resistant to root rot and stem nematode.

2. Virus-free variety: Beijing 553. After virus removal, yield increased by more than 40%. Sprouting ability and growth vigor are both significantly improved; tuber skin yellow, tuber flesh apricot-yellow. Advantages: soft and sweet eating quality, resistant to stem nematode. Relatively high yield; high-yield spring sweet potato fields produce about 4,000 kg per mu, summer sweet potato more than 3,000 kg. Disadvantages: not resistant to root rot.

3. High-yield, early-maturing: Anping No. 1 (yellow-skin Su 8). Advantages: high yield, early-maturing, red flesh, smooth yellow skin, good marketability. Fresh tuber yield slightly higher than Sushu No. 8, more than 35% higher than Xushu 18, average dry rate 23.3%. Spring sweet potatoes reach more than 2,500 kg/mu after 3 months of growth, reaching the market in mid-August at a high price with good returns, generating 1,500-2,000 yuan per mu. Disadvantages: not resistant to root rot, average eating quality.

4. Sushu No. 8. Advantages: early-maturing, high-yield, ranked first in fresh tuber yield in provincial regional trials, more than 30% higher than Xushu 18, spring sweet potato yield more than 4,000 kg per mu; summer sweet potato more than 3,000 kg, good early maturity, resistant to stem nematode and black spot. Characteristics: short vines, semi-upright type, top leaves green, veins green, leaf shape compound-notched, stems green, many branches. Tuber skin red, tuber flesh orange-red. Average dry rate 21.8%, average eating quality. Disadvantages: average eating quality, not resistant to root rot.

5. Purple sweet potato variety: Jishu No. 18. Advantages: high yield, high quality, disease-resistant, short vines. High fresh tuber yield, tubers form neatly. Spring sweet potatoes generally yield 2,500-3,000 kg per mu, more than double that of Shanchuanzi. About 10% higher yield than Xushu 18. (3) Excellent quality. Tuber skin purple, summer tuber flesh purple (spring tuber flesh light purple), tuber shape long spindle, smooth, commercial rate as high as 90%, spring sweet potato drying rate about 33%, summer sweet potato about 28%, flesh relatively sweet and glutinous. Good for fresh eating and health benefits, and can also be processed for natural anthocyanins. Resistant to root rot, relatively resistant to stem nematode. Disadvantages: poor resistance to black spot; pay attention to using carbendazim for disease prevention.

6. Purple sweet potato variety: Qunzi No. 1. Advantages: high yield, high quality, good appearance, disease-resistant; tuber skin black-purple, tuber flesh purple, taste relatively sweet, mealy and fine. Fresh tuber yield close to Xushu 18, 1.57 times higher yield than Japanese Shanchuanzi, dry rate 30.0% close to Xushu 18 (29.9%), and its shade tolerance and fertilizer tolerance are clearly superior to Shanchuanzi. Characteristics: top leaf color and leaf color both green with brown, leaves palm-shaped, vein color and stem color both purple, vines relatively short. Initial appraisal: resistant to stem nematode, moderately resistant to black spot; root rot resistance not yet appraised.