2. LITERATURE REVIEW
2.1 Origin and Distribution
Tannia was originated in tropical America, but currently grown widely as a subsistence food crop in Asia, Africa and Polynesia (Bown, 2000). From five crops which are under sub family aroid the only tannia originated from Central & South America others originated from South-east Asia (Lebot, 2009).
When the Europeans arrived, it was further known to have been grown from Southern Mexico to Bolivia in the Latin America. Only during the 19th century, it spread widely throughout the tropical world. Currently, it is cultivated in tropical and subtropical zones, between latitudes 30⁰ North and 15⁰ South. The main areas of distribution of the crop include the Caribbean (Cuba, Dominican Republic, Puerto Rico, West Indies), Central and South America; USA (Florida, Hawaii), West Africa (Cameroon, Ghana, Nigeria, Togo), and tropical Asia ( Indonesia, Malaysia, the South Pacific Islands) (Perez, 2010).
Tannia was introduced between the 16th and 17th centuries to Central and West Africa, where it was given the common name of cocoyam because of its resemblance to Colocasia. It was brought by Portuguese slavers into SaoTomé and Principe, where they had important trading bases and was spread further by traders, missionaries and other travelers (Bown, 2000; George, 2011). It was introduced to Ethiopia in 1978 (Amsalu et al., 2008).
2.2 Botany
Tannia is a herbaceous, monocotyledonous, perennial plant, but for practical purposes, it is harvested after 6 -12 months of growth (Castro, 2006; Ramesh et al., 2007; Lebot, 2009). Photo synthetically it follow C-3 pathway (kay, 1987). It can reach up to a height of about 2 m and have a short erect stem, having a corm or main underground stem in the for...
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...l differences on tannia accessions on the length of petiole, leaf blade length and width, and size cormel.
According to Lebot (2009), about 1000 accessions of X. sagittifolium, X. violaceum, X. nigrum, X. brasiliense and X. yucca were collected from different part of the world. The majority was collected from Cameroon, Equatorial Guinea, Gabon, Ghana and Togo. Ethiopia with its diverse agro-ecologies and suitable environments, allows the growth of numerous root and tuber crops; mostly in the South and Western parts of the country by smallholder farmers (Asfaw, 2005). Both taro and tannia are grown mostly throughout the hot and humid areas of southwestern Ethiopia. In the area there is a large genetic pool of tannia in farmers’ field and homesteads (Amsalu and Tesfaye, 2006), and more than 80 accessions of tannia were collected from the area (Amsalu et al., 2008).
Old World crops such as wheat, barley, rice, and turnips had not traveled west across the Atlantic. Some of the New World crops that hav...
Volpato, G., Godinez, D., Beyra, A., & Barreto, A. (2009). Uses of Medicinal Plants by Haitian Immigrants and Their Descendants in the Province of Camagüey, Cuba. Journal of Ethnobiology and Ethnomedicine, 1-9.
McIlroy, R.J. 1963. An introduction to tropical cash crops. Ibadan University Press, Nigeria. 163 pp.
As a result of these factors, the flora has adapted to these conditions in a variety of ways including their shape, leaf type, root system, and color. One of the most prominent adapt...
...South America and became important export crops in West Africa in the 20th century. While little information was provided on our specific topic, this source was useful for the information of the Columbian Exchange.
Two members of the group were instructed to visit the laboratory each day of the experiment to water and measure the plants (Handout 1). The measurements that were preformed were to be precise and accurate by the group by organizing a standardized way to measure the plants. The plants were measured from the level of the soil, which was flat throughout all the cups, to the tip of the apical meristems. The leaves were not considered. The watering of the plants took place nearly everyday, except for the times the lab was closed. Respective of cup label, the appropriate drop of solution was added to the plant, at the very tip of the apical meristems.
Janick. J. (2011). Center for New Crops & Plant Products - Department of Horticulture and
Taigas have some small-leaved deciduous trees like birch, alder, and willow. Mostly in areas escaping the winter cold. There are two major types of taiga. The one in the south is the closed canopy forest, it has ma...
It is reported that the C. Arabica shrubs in Ethiopia rainforest have more genetic materials than the commercial cultivars used to produce most coffee around the world. The C.arabica shrubs occur naturally in moist evergreen undergrowth of the Ethiopian Afromonate rain forest between 1000 and 2000 meters above sea level. This made Ethiopia the third largest C.arabica coffee producer next to Brazile and
Since the plant’s domestication the sunflower has been one of the most important crops in production that is native to North America, comparable to maize and wheat. The sunflower, what was once a plant utilized only in the Americas is now one of the most widely and diversely recognized used plant species in the world.
There is limited information in the literature on propagation of A. spicata. Dirr and Heuser (2006) found that warm and cold stratification of seeds promoted germination, although associated durations are not available. Softwood stem cuttings of A. spicata have also been successful when rooted in sandy soil, but the types of growth hormones and/or concentrations were not included (Dirr and Heuser,
The condensed tannins are even further categorized into many different sub-types pertaining to the compounds structure and linkages of their flavonoid groups (Barbehenn and Constabel 2011). Plant species with secondary or woody growth have been found to contain generous amounts of condensed tannins (Hattenschwiler and Vitousek 2000). Conversely, these condensed tannins are generally absent within the herbaceous plants (Hattenschwiler and Vitousek 2000).
This investigation will focus on finding the differences in the number, position and sizes of stomata and the effects on the rate of transpiration. More specifically it will compare the stomata of Geranium and Ixora and their ability to transpire. How do the stomata of Geranium and Ixora differ and what effect does this have of their rate of transpiration?
Fossil records are unable to provide information of on the center of origins of the cacao tree. The cacao tree is in the Sterculiaceae family. The first growers of the cacao pods were probably the people who entered the lowland rain forests of the Amazon Basin between 10,000 and 200 B.P. The full name of the cacao tree is Theobroma cacao. Most of the information of the cacao have been derived from the cultivated crop. The life and reproduction life cycle of Theobroma cacao is identical to a tropical rain forest tree species. Cacao grows optimally in minimal moisture and shade. Cacao is dispersed in small, medium and large areas. This is probably the result of animal dropping the seeds after eating the tasty inside of the pods. Cacao pods are very diverse in morphology. These morphological difference suggests genetic differentiation.