XII Sweetpotatoes Around the World
1. World sweetpotato production and
consumption
(1) In 1998, total worldwide plantings of sweetpotatoes came to 8.87 million ha, with production per ha of 14.6 tons and overall production of 130 million tons, about half that of potatoes. Asia accounted for 90% of the world's production of sweetpotatoes, with China alone accounting for a massive 86% of world output. The second largest producer of sweetpotatoes was Indonesia (1.9 million tons), followed by Uganda (1.89 million tons), Vietnam (1.5 million tons), India (1.2 million tons), Japan 1.13 million tons, and Rwanda (1 million tons).
(2) FAO statistics (1996-98 average) show that the countries with the highest annual per capita sweetpotato consumption are the Solomon Islands (173.8 kg), Rwanda (117.4 kg), Burundi (96.7 kg), Papua New Guinea (86.3 kg), Uganda (79.4 kg), and China (41.1 kg). Continuing, Kenya, Madagascar, Comoro Islands, Vietnam, and so on, each have an annual per capita sweetpotato consumption of about 20 kg. In terms of annual per capita consumption of fresh and other forms of sweetpotato, Japan leads among developed countries, at 4.9 kg, with New Zealand (2.7 kg) and the US (1.4 kg) trailing behind. In USA households, commonly consumed processed forms of sweetpotato include canned, and so on.
China has the largest share of world sweetpotato production. Major areas of production include Sichuan, Shandong, and Henan. Although total plantings rose as high as 9 million ha in the 1960s, they dropped to 7 million ha in 1975-79, and have since declined to the 5 million ha range. This is probably because sweetpotatoes have been replaced by soybeans and corn as the Chinese diet has improved. Meanwhile, yields rose over the same period from 10 tons/ha to 15 tons/ha, then to 17-19 tons/ha.
Before 1960, 50% of sweetpotatoes were used as a staple food for farmers, and 30% for feed. At present, however, 60% of sweetpotatoes are used for feed (for pigs) and 30% for processed food (starch, noodles), with household use and planting use accounting for 5% each.
Well-supported breeding-research programs are underway at agricultural science institutions in all provinces and at the Xuzhou Sweetpotato Research Center. Chinese scientists have made repeated improvements based on the "Shori No. 100" (Okinawa No. 100) introduced from Japan. A hundred different varieties of sweetpotato, including the "Josho No. 18," are now being cultivated in China, and cultivation technology has been improved.
China currently exports dried sweetpotatoes, baked sweetpotatoes, fried sweetpotatoes, paste, and other frozen prepared sweetpotato products to Japan. At 15-18 locations, there are factories producing about 12,000 tons of products for export to Japan. Such processing was previously concentrated in the Shanghai area, but production has now moved inland, with Anhwei Province alone producing about 10,000 tons. Takao Komatsu provides details of these matters at his website in Japanese "Akai yuuhito daigakuimo" (A Red Sunset and Deep-Fat Fried, Candied Sweetpotato Chunks) [http://www.oct.zaq.ne.jp/afabw102/].
In Korea, sweetpotatoes are cultivated in southern areas such as Chollanam-do and Kyongsangbuk-do. Especially in the former area, sweetpotatoes for starch-related products are produced mainly on Chejudo and for table use in the Kainangun. Larger-scale farming operations having about 30 ha of farmland are common. As in China, sweetpotato production has declined in recent years: down from more than 150,000 ha of plantings to 100,000 ha in 1970, then to less than 50,000 ha in the 1980s. Today, plantings are no more than 14,000 ha. And while 70% of production went for household consumption in the 1960s, consumption has declined sharply as living standards in Korea have risen. At present, consumption for household use accounts for 40% of production, with starch-related products at 25%, and alcohol at 20%. Once processed , this starch is used mostly for harusame noodles. Plant foliage is generally utilized as a vegetable, a practice characteristic of Korea. Widely cultivated varieties include "Shinyulmi" and "Yulmi," bred in Korea, and (for processed food) "Hongmi" and "Eunmi." "Kokei No. 14" introduced from Japan is also cultivated.
Korean farmers use four different cultivation schedules: a very early crop (planting in February - harvesting in late June to early July) using mulch in greenhouses; an early crop (planting in April - harvest in the July-early August) using mulch; a standard crop on open farmland (planting in early May - harvest in early September); and a late crop (planting in mid-June - harvest in mid-October). Use of early and very early cultivation is increasing.