Better Farming Series 44 - Processing of Cassava and Sweet Potatoes for Animal Feeding (FAO, 1995, 49 p.) About the sweet potato plant (introduction...) Time of tuber harvest What tuber yields can you get?

Better Farming Series 44 - Processing of Cassava and Sweet Potatoes for Animal Feeding (FAO, 1995, 49 p.)

About the sweet potato plant

181. Up to now in this booklet, we have learned about cassava. Let us now study sweet potatoes. We will learn about the feed value of sweet potato tubers and how to process them.

182. Sweet potato tubers are starchy like cassava roots.

183. Sweet potatoes are an important source of food in Asia and the Pacific. They are a major crop in China, the Philippines, Papua New Guinea and Pacific Islands.

184. More than 90 percent of world sweet potato production comes from Asia. China is the world's largest producer. It produces over 80 percent of world production.

185. Sweet potato is a creeping plant. It is a perennial and can grow for several years.

186. But it is cultivated now mainly as an annual crop.

187. The herbaceous stem of the sweet potato plant is called the vine. The vines are thin and trailing.

188. Some sweet potato cultivars grow like a bush. Some cultivars have vines of medium length. Others have long vines.

189. The size and shape of the leaves also vary widely among different cultivars. At least 15 different leaf types are known.

Leaves

190. Sweet potato tubers differ greatly in shape, colour of skin and colour of flesh.

191. Tubers may be round or elongated. The colour of the skin can be white, yellow, orange, red, purple or brown. The colour of the flesh can be white, yellow, orange, reddish or purple.

Time of tuber harvest

192. You have learned in Booklet No. 16 how to grow sweet potatoes.

193. In the humid tropics, sweet potatoes can be grown throughout most of the year. You can plant and grow them at any time of the year.

194. The age at which sweet potatoes should be harvested is determined by the type of cultivar. Some cultivars can be harvested 90 days after planting. Other cultivars may require as long as 350 days.

195. In many countries, tubers are usually harvested progressively as they develop and as they are needed.

196. As with cassava, ground storage can be used for sweet potatoes. For example, 90- day cultivars can be left underground for another 45 days after maturing.

197. The time for harvesting is also determined by the weather and pest problems in the area.

198. If heavy rains are expected, you must uproot the tubers early. Otherwise they will rot. If insect pests are a problem, you must harvest the tubers before damage becomes severe.

What tuber yields can you get?

199. Sweet potato plants yield more food than cassava plants do.

The average yield of cassava roots worldwide is 9 600 kg to the hectare, whereas the average yield of sweet potato tubers worldwide is 13 900 kg to the hectare.

200. In average farms, tuber yields vary from 5 000 to 11 000 kg to the hectare.

201. In some parts of China, the average yield of tubers is 17 000 kg to the hectare.