Studies on dry matter distribution, harvest index and proximate composition in different accessions of hausa potato (Solenostemon rotundifolius (poir) j. K. Morton) in jos-plateau, Nigeria

The Hausa potato (Solenostemon rotundifolius (Poir) J. K. Morton) is a tropical, multipurpose, minor tuberous root crop. It is one of the best staple tuber crops in terms of its distinctive fragrance, peculiar taste, medicinal, nutritional and economic values. It is cultivated in the West African countries of Ghana and Nigeria.1 The plant is a small herbaceous, dicotyledonous annual, 15 – 30cm high, prostate or ascending, with a succulent stem and thick leaves. It has an aromatic mint-like smell. Flowers are small and may be white, blue, pink or pale-violet in colour, and are produced on an elongated terminal with distal inflorescence and slender false spikes.2 It has small darkbrown edible tubers produced at the base of the stem. Vegetatively propagated tuber crops like the Hausa potato play a fundamental role in improving food security, human nutrition as well as other uses in the agro-industrial chain. They can be used as substitute for other types of crops in times of economic needs, such as high food prices, bridging the hunger gap between planting and harvesting of the main staple crop or inadequate supply of food in times of famine.3 Currently, its genetic resources are disappearing into extinction due to unfavorable features like the small tuber size,1 branching of the tubers (which makes them less attractive to consumers), low yield occasioned, perhaps, by lack of balance between its source potential and sink capacity as well as the intense labour required in its production. Consequently, it is being gradually replaced by more popular root and tuber crops like the potato, sweet potato, cassava, cocoyam and yam, which are higher-yielding. The crop is presently classified as an endangered species. The United Nations has predicted that the global human population would rise from 7 billion in 2011 to 9 billion by 2050, and that the world food production would need to increase between 70 and 100 per cent in forty (40) years.4 Most of the increase will need to come from bridging the gap between what is currently achieved per unit land and what should be possible in the future, given the most appropriate farming methods, food storage facilities, availability of suitable cultivars and adaptation to climatic changes.4 With the ever-increasing population coupled with limited land, water and other resources, the future beckons on tuber and root crops, including the Hausa potato, in fulfilling the country’s food requirements. The Hausa potato has a very high biological efficiency with a profound production potential per unit area of land.5 Farmers growing this crop follow indigenous agronomic practices which, coupled with lack of high-yielding varieties, result in generally low yields. The yield can be increased by adopting improved production