Agricultural Academy

This paper seeks to promote sweetpotato (Ipomoea batatas L. (Lam) through the diversification of its use in the Nigerian food industry. Sweetpotato was cultivated in few areas by farmers in Nigeria before the recent increase and spread in the last decade, and its use is limited to boiling, roasting and frying. The processing of sweetpotato, as highlighted in this paper, has the potential of making a significant impact on the economy. This is because processing offers the possibility of better storage, added value, lower transportation cost and new markets in the food, feed, and industrial sectors. It will facilitate the marketing of this crop, increase productivity and improve the standard of living by providing income for farmers. The use of sweetpotato in livestock feed will help to improve livestock nutrition and lead to cheaper meat production. Sweetpotato therefore, can play a major role as a food reserve for many rural and urban households, due to diversified usage. Recommendations include identifying and breeding the varieties that will be suitable for different end products so as to enhance its production. There is also the need to determine how the different varieties can be made available all year round by establishing multiplication sites. Industries or entrepreneurs who will be ready to buy must also be identified, for promotion of commercial production. Technical advice must also be provided so as to improve yields

Diallel Analysis of Sweet Potato [Ipomoea batatas (L.) Lam] Genotypes for Combined Beta Carotene and Dry Matter Content in Southern Guinea Savanna, Nigeria

Roots of orange - fleshed sweet potato varieties currently available in Nigeria contain high quantities of β - carotene or pro - vitamin A but have high moisture content. These varieties have been found to be a cheap and crucially important remedy for vitamin A deficiency. The cream or white - fleshed varieties, on the other hand, have a sweet taste with high dry matter content, giving a dry texture, a quality trait preferred in Nigeria. Development of sweet potato genotypes that can combine these two important quality traits is the objective of this breeding work. A diallel experiment using six parental sweet potato genotypes crossed in all possible combinations were carried out and thir ty progenies were evaluated for beta carotene (β - carotene) and dry matter content in Landmark University, Omu Aran, Kwara State, Nigeria. The 30 F 1 progenies along with their parental lines were planted in the same field trial. The trial was laid out in 6 x 6 triple lattice in two replications. Highly significant (P ≤ 0.01) differences were observed among the genotypes for the traits. The average β - carotene content among the progenies was 2.86 (mg/100g.f.w) while the dry matter c ttg ontent had a mean value of 31.89%. The cross progenies 199024.2 x Excel had the highest beta carotene (14.37mg/100g.f.w) content with the highest dry matter content (40.10%) and are therefore recommended for further evaluatio

Artificial Pollination, Pollen Viability, and Storage in White Yam

We pollinated while yam (Dioscorea rotunda/a) by hand using three techniques: a camel-hair brush was used to pick up and transfer pollen from anthers to stigmas of open female flowers: a pointed tip of a bamboo splinter was used to excise anthers from open male flowers and to insert them into open female flowers; and pollen suspension in an aqueous culture medium was dropped through a blunt-tipped 1-2-ml syringe into open female flowers, The brush technique was most effective and yielded 147 seeds per day compared with 49 and 11 for the splinter and the dropper techniques, respectively. The potentially high seed yield per day of the brush method resulted mainly from the high percentage of fruit set (27 .8) and the large number (450) of flowers that could be pollinated in a day

Floral Biology and Pollination Efficiency in Yam (Dioscorea spp.)

Yam (Dioscorea spp.) is a monocotyledonous herbaceous vine cultivated for its starchy underground or aerial tubers in the tropics and subtropics. It is an allogamous and polyploid species that reproduces by both sexual and asexual mechanisms. However, many of the landrace cultivars, including most of the popular varieties, reproduce exclusively by vegetative propagation (planting the tubers). These varieties are either sterile or produce sparse and irregular flowering with high flower abortion rate, low fruit and seed set. Production of crossbreed seeds for genetic improvement and for maintaining genetic diversity in yams is, therefore, mainly achieved through natural or managed pollination. Flowering in yam is mostly dioecious and, in some instances, monoecious. Flowering asynchrony, sticky nature of the pollen grains, and cross incompatibility are among the challenges in making genetic progress in yam breeding. There are many limitations in basic and applied knowledge of yam flower biology and pollination. This paper, therefore, reviews the flowering biology, pollination, and methods of improving pollination efficiency in yam breeding programs

Economic analysis of seed yam production systems in Nigeria

New seed yam systems from minisetts, minitubers and vine cuttings have been developed for yam production to supplant the traditional systems, which have proven inefficient and costly. The new techniques provide producers in tropical countries with the opportunity to minimize production costs, reduce seed yam price and promote greater seed availability. A discounted cash flow budget with a whole farm perspective was used to analyse the economic performance and risk implications of a hectare investment in the new seed yam system over time for a representative farm. Data based on realistic process costs and review of past reported studies were employed to reflect the relative economic worthiness and opportunity cost of investment and operating capital of seed yam systems in Nigeria. From the net present value (NPV) and benefit:cost ratio (BCR) analyses, the new seed yam production systems were more viable than current traditional seed yam production systems through milking of live immature plants. This raises the need to identify which among the new production techniques could be the most profitable and recommendable. Therefore, understanding the economics of seed yam production systems would not only help a significant proportion of local, regional and national stakeholders but also assist the policymakers, funding agencies and other organizations involved in yam projects and programmes

Biotechnology approaches in breeding for biotic stress resistance in yam (Dioscorea spp.)

Yam (Dioscorea spp.) is a major staple and cash crop in tropical and subtropical regions. However, biotic (fungus, viruses, tuber rots, nematodes, insects, etc.) and abiotic stresses (drought, low soil fertility, etc.) substantially impact the productivity and quality of yam crop in regions where it is majorly cultivated. Developing and deploying resilient cultivars is a cost-effective and environmentally sound approach to enhance productivity in stressful environments. Breeding initiatives in yam to develop improved cultivars have long relied on conventional or classical methods, which are time-consuming and labor-intensive. However, in recent years, biotechnological approaches are being successfully introduced into yam genetic improvement to shorten the breeding cycle, optimize parent selection, predict cross and progeny performances, identify seedling sex, and break interspecific hybridization barriers among yam species. The approaches include next-generation sequencing-based genotyping, transcriptomics, metabolomics, genetic transformation, gene editing, genome-wide association studies, genomic prediction, marker-assisted selection, in vitro culture, ploidy analysis, and somatic hybridization. Although several advances have been attained in yam research to identify regions controlling key traits for biotic stresses, there is low translation to widespread applications in yam cultivar development. This chapter reviews the status and prospects of resistance breeding for yam and discusses biotechnology approaches in breeding multiple-stress-resistant cultivars. In addition, it provides insights in to the broader implementation of biotechnological tools in yam breeding and research