Roots and tubers
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Item The Effects of Packaging Materials on Keeping Quality of Cassava Root-Leaf Flakes(East African Journal of Science, Technology and Innovation, 2021-05-25) Masha, C.K.; Okoth, M.W.; Abong', G.O.; Shibairo, S.I.; Kenya Agricultural and Livestock Research Organization (KALRO) ; University of Nairobi ; Kibabii UniversityProcessing and value addition is necessary for fresh agricultural commodities in order to reduce perishability and prolong shelf-life. Shelf life is enhanced with proper packaging because packaging materials influence storage period, preserve nutrients and sensory qualities. This paper objectively determined the effects of packaging materials on nutrients quality of cassava flakes. The methodology of the work involved the use of blends of cassava flakes packaged in Kraft, insulated polythene and plastic, and stored in an incubator at 550C and 75 % relative humidity for 5 days. Three blends of cassava flakes identified by panelists as the most preferred (20 % leaf, 100 % fresh root, 100 % fermented roots were developed and studied on accelerated shelf life trial. Storage period and packaging material were determined. The results showed moisture content to be significantly influenced by packaging material whereby it increased over the storage period, across the blends, with highest levels (10.75-%) registered in kraft material on day 3. After day 3 all nutrients showed a drastic decreasing trend with the most affected being protein that dropped from; 22.94 mg / 100g to 8 mg / 100g in the blend containing 20 % leaf in and 6.65 mg / 100g to 2. 8 in the blend of 100 % fresh root packaged in kraft materials. There was Paper insulated polythene (gunny) was shown to contain highest nutrients’ levels by day 5 with; protein at 27.68 mg /100g vitamins A (576.85 mg/100 kg), Zinc (1.17 mg /100 g), iron 3.69 mg /100g), fibre 6.12 mg /100g. Fat was highest at 9.71 mg/100g in the plastic material. The study therefore concluded that insulated polythene is the best packaging material for cassava flakes and the product’s shelf life is up to 3 months.Item Formulation of Cassava Root-Leaf Flakes, Acceptability Evaluation and Determination of Nutritional Value(East African Journal of Science, Technology and Innovation, 2021-05-25) Masha, C.K.; Okoth, M.W.; Abong, G.; Shibairo, S.; Kenya Agricultural and Livestock Research Organization (KALRO) ; University of Nairobi ; Kibabii UniversityCassava is an important food crop grown for its roots to supply daily needed calories to households in the cassava growing communities including coastal Kenya. The region contributes up to 30 % of the national cassava production though it remains food insecure with a high prevalence of malnutrition. Cassava roots are deficient in most nutrients except carbohydrates while the leaves are rich in a range of nutrients including protein but are moderately consumed as vegetables. The study sought to establish the most acceptable cassava root-leaf blend/s with improved nutrients’ content. This involved formulation of blends of cassava flakes through mixing roots and leaves in varying levels ranging from 0 % to 50 % that led to 18 different blends, with most accepted being 20%. Fermented and unfermented flakes were developed. A total of 18 formulations were developed before consumer acceptability and nutritional content were determined in the most preferred blends. The results showed cassava root-leaf flakes were best accepted when fermented root material is blended with 20% leaf component. Percent leaf content above 40% was unacceptable as such blends exuded poor smell. A calculation from the nutrients contained in blend 100 5 cassava roots against the blend that contained leaf material showed that the nutritional value showed that cassava root-leaf flakes have vitamins A and C improved by 353% and 53%, minerals- iron and zinc by 5.6% and 85% respectively and protein by 430% when compared with flakes processed from 100% cassava root. It is recommended that more studies be carried out to determine the bioavailability and nutritional effect of consumption of the flakes on children and pregnant women.Item Analysis of the Cassava Value Chain in Reference to Smallholder Farmers in Busia County, Kenya(Asian Journal of Agricultural Extension, Economics & Sociology, 2023-03-08) Emongor, E.A.; Makokha, S.; Matere, S.; Nzuve, F.M.; Githunguri, C.; Kenya Agricultural and Livestock Research Organization - Food Crops Research Institute & Biotechnology Research Institute ; University of NairobiA survey was undertaken in Busia County, Kenya to obtain data for the situational analysis of the cassava value chain. Two hundred and forty-five households were sampled and interviewed in the months of August and September 2021 in Teso South Sub-County, Busia County. Descriptive statistics methods were used to analyse data using Statistical Product Service Solutions (IBM SPSS) version 20 Software. The results showed that the average land size in the study area was 2.7 acres. The mean land allocated to cassava was 0.25 acres. Those interviewed grew cassava mainly for subsistence while the surplus is marketed. Results also showed farmers preferred to grow local varieties (68.4%), improved varieties (21.6%) and a combination of improved and local varieties (10%). The adoption of improved cassava varieties in the study sites was still low. Most of the farmers obtained their income from on-farm sources (71.8%). The major source of information was the farmer-to-farmer extension approach with approximately 66% of respondents obtaining information from other farmers. The farmers like growing local varieties as they have traits that make them preferred to the farmers. The adoption of the improved varieties was still low. More needs to be done on both production; processing and marketing if cassava is to contribute to the food security and income of the households in Busia County.Item Review of Kenyan Agricultural Research Vol. 22 Root and Tuber Crops(Kenya Agricultural Research Institute, 1997) Mailu, A.M.; Kenya Agricultural Research InstituteThese reviews have been produced as part of the Kenya Agricultural Research Database Project which was funded by the Netherlands government over the years 1992 to 1996. The aim of the project was to document all investigations and research related to agriculture in Kenya undertaken since the end of the last century, especially those items which had not been published. The computerized database now contains around 40,000 records, most containing abstracts or summaries, full bibliographic details, and information about where the documents can be found. We are conscious, however, that many items have not yet been included, especially the earlier material and many consultancy reports produced by the foreign and international donor, development, and research organisations. Specialists who read the reviews may be aware of important topics which have been omitted by the reviewer. If this is the case, we would ask that both the reviewer and KARl's Library and Information Services be informed so that the topic can be included in future revisions. Constant up-date will be required as new research information becomes available with the National Agricultural Research System in Kenya.Item Guidelines for Production of Healthy Seed Potatoes In East And Central Africa(Kenya Agricultural Research Institute, 2006) Kabira, J. N.; Wakahiu, M.; Wagoire, W.; Gildemacher, P.; Lemaga, B.; Kenya Agricultural Research InstitutePotato is an important food and cash crop in East and Central Africa. It plays an important role in national food and nutrition security, poverty alleviation, and income generation and provides employment in production to consumption continuum. Potatoes mature in 3-4 months and can yield up to 40 t ha-1 • Most farmers obtain less than 10 t ha·1, mainly because of poor growing practices, low use of inputs and poor control of insect pests and diseases. Supply of good quality planting materials of improved varieties and timely availability can boost production of potatoes. Most farmers save and-plant seed from their own fields, or buy small tubers from neighbours or local markets. These practices allow diseases to build up resulting in low yields even when following recommended fertilisers and fungicides rates. Farmers should renew their seed stocks from clean sources such as research stations at least every 2-3 years, and then manage this seed carefully to minimise build-up of diseases and pests. This manual explains how to produce disease-free seed potatoes to support over one million ware potato growers in the region whose standard of cultivation requires to be upgraded.Item Analysis of Structure Conduct and Performance of Sweet Potato Marketing the Case of Nairobi And Kisumu Kenya(Egerton University, 2010) Gichangi, A.W.Sweet potato can potentially contribute significantly to Kenya's national objective of enhancing food security. The crop withstands drought and it is easy to grow. It can also play an important role in the diets of many rural households. Despite this importance, sweet potato is not adequately market-oriented and the competitiveness of smallholder farmers is limited by low productivity and poor quality of traditional varieties. The crop is the source of raw materials for agricultural industries. The organizational structure of Kenya's sweet potato industry and its performance are poorly documented. The study aimed at assessing the structure, conduct, and performance of the sweet potato marketing system in Nairobi and Kisumu, identifying and characterizing the opportunities and constraints on market participants that influence its performance .. Data used for analysis in this work was collected using a formal survey instrument during 2009. The survey instrument was specially designed to track the alternative channels used in sweet potato transactions and to capture the associated prices, volumes, and transaction costs in the source and final markets along the value chain.Item Agri-business Development Support Project (ADSP) July-Sept 2001(Kenya Agricultural Research Institute, 2001) Kenya Agricultural Research InstituteThe degeneration trials were harvested on the 15th, 16th, and 17th of August in Ngecha, Murengeti, and Tigoni Centre respectively. The treatments consisted of dressing with a systemic insecticide, foliar spraying with insecticides, and untreated and unsprayed plots. In addition, a trial to compare the yield difference between first, second, and third-generation seed tubers was harvested at Tigoni on 24th August. Two varieties, Tigoni and Asante were used. The experimental design was an RCBD replicated three times. The yields were 31.6, 28.0, and 18.9 tlha for the first, second, and third-generation seed tubers respectively. ii) Harvesting of the trial on early and medium maturing varieties was done in Kakamega, (Kabras East Division) and Laikipia (Ngecha Division) on 4th and 6th September respectively. Results showed that the best performer in both.Item National Agricultural Research Project Quarterly Report of Activities and Progress July - September, 1995(National Potato Research Centre, 1995) National Potato Research CentrePersonnel - Dr. R. S. Malik was on home leave in the U.S. during portions of July and August. Vehicles - Transport for Technical Advisors is satisfactory. Due to reductions in staffing, two Isuzu Troopers were transferred from MIAC to KARI. Finance and Accounting - On July 20, the annual work plan and budget for the period July 1, 1995 - June 30, 1996 was approved by USAID and PIL 33 issued. The annual increment of funding to the KARI MIAC Contract for the period is $2.6 million. This is about 900,000 less than was planned for when NARP II was approved.Item Potato growing in Kenya improvement through disease control, varietal selection and provision of healthy stock(Kenya Agricultural Research Institute, 1976) Todd, J.M.; Kenya Agricultural Research InstitutePotatoes are thought to have been introduced to East Africa by the early European settlers.How this was done and with what rate of success,how varieties suited to tropical upland conditions came to be selected,and how the crops was taken up by African cultivators are all parts of a story yet to be compiled from whatever primary sources remain.Item National Agricultural Research Project Quarterly Report of Activities and Progress July - September 1994(National Potato Research Centre, 1994) National Potato Research Centrenel - Dr. and Mrs. Filmore Bender departed Kenya July 30 at the end of his two-year tour of duty as long-term Research Management Advisor and Chief of Party. The Research The management Advisor position was not filled and Dr. Robert Hudgens is serving as MIAC-MU Team Leader in addition to his duties as Systems Agronomist.Item KARI Potato Research Priorities in Kenya: KARI impact assessment series(Kenya Agricultural Research Institute, 2001) Kenya Agricultural Research InstitutePotatoes are a high priority food crop in Kenya given that they occupy the 2nd place to maize as food energy source. The national potato research programme, continues to face a serious problem of scarce resources. As a result, the programme is under pressure to demonstrate clearly the benefits the taxpayers can expect from the resources that are availed and utilised in support of agricultural research.Item Storage and Processing Characteristics of Three Kenyan Potato Varieties(Jackson Ntongai Kabira, 1983) Kabira, J.N.The studies presented here were conducted to determine the storage and processing characteristics of three established Kenyan varieties of potato (Solanum tuberosum). They included the red-skinned Kerr's Pink and Desiree, and the white-skinned Kenya Baraka varieties, and were grown under similar cultural conditions at the National Potato Research Station (NPRS), Tigoni. Tests were carried out over a period of three growing seasons, starting in 1980/81.Item Breeding Cassava for Virus Resitance(1947) Nicholas, R.F.W.; AmaniSo long as cassava (Manihot utilissima Pohl.) continues to rank as a staple food for a large proportion of the indigenous population of East Africa, the improvement of the crop must figure in the agricultural economics of the country. The comparative freedom of the crop from pests, and its drought resisting qualities, render it of particular value as an "insurance policy" against famine when it is less afflicted by drought and locusts than other crops. That it is, however, subject 'to great reduction in yield, due to infection by the mosaic virus, has been recognized for many years. In Zanzibar, Briant and Johns (1940), have shown that the loss in a non-tolerant variety, propagated from diseased cuttings, may be as high as 95 per cent. Experimental work at Amani demonstrated that this virus was transmitted by a white fly, Bemisia sp. (Storey and Nichols, 1938); field experiments showed that natural infection was mainly seasonal and in certain areas extremely high. These experiments also demonstrated that some varieties are less prone to infection than others. This disease occurs throughout East AfricaItem Environment and the Growth of the Potato (Solanum Tuberosum) in Tropical East Africa(1943) Glover, J.; East African Agricultural Research Institute AmaniThe potato S. Tuberosum, which was possibly introduced into east tropical Africa as a subsidiary food crop for Europeans, is now for many Africans an appreciated source of food and others a cash crop of importance. Though a successful introduction, the yields of tubers have generally been lower than those obtained in temperate zones. Some have suggested that this might be due to the detrimental effect of short daylength and high air and soil temperatures. Moreau [1], in a survey of the climatic background of the commercial potato-growing areas in E. Africa, mainly in the cooler zones above 4,000 ft. on the mountain, masses, concluded that 'given good husbandry, excellent crops of S. Tuberosum can be raised in parts of tropical Mrica, even though air and soil temperatures seem unfavorably high. The short days seem to be of no practical importance.' He stresses, however, that his data are scanty.Item The Yield and Maturity Period of Potatoes (Solanum Tuberosum) at Low Latitudes(1943) Moreau, R.E.; East African Agricultural Research Institute AmaniVery definite opinions have been expressed that the potatoes of commerce are long-day plants. For example, Bald [I] writes that commercial potatoes 'produce a full crop where they receive more than 13 hours of full daylight each day. Many will produce 50 to 75 percent. Yield under short-day conditions, but never their maximum crop.' Even more emphatic statements have been made by Driver [2]: 'It has always been difficult, if not impossible, to grow potatoes in tropical countries. This is because potatoes have been bred for and become adapted to the light conditions of temperate regions and form tubers only when the daylight period reaches a certain minimum. In tropical regions, the daylight period does not exceed twelve hours, and this is insufficient to initiate tuber development.' Because short day-length is one invincible circumstance of tropical agriculture, and because the question is fundamental to a policy of potato selection for the tropics, the evidence I. for such statements as the foregoing needs dose examination. It is of course obvious at the outset to anyone aware of the East African potato-growing industry that the last part of Driver's statement does not apply to that country.Item Studies of the Mosaic Diseases of Cassava(1938) Nichols, R.F.W.; Storey, H.H.; East African Agricultural Research StationThe symptoms of mosaic disease in cassava, although generally typical of the mosaic group, show wide variations, due in part to the varietal reaction of the plant, to its stage of development and to the environment. The most important cause of variations however is differences in the strains of the virus, of which we have recognized, through the study of symptoms, two groups of severe and mild strains. The viruses are transmitted across a graft, but we have failed to obtain mechanical transmission by needle or hypodermic injection. A Bemisia sp. can transmit both groups of strains. It can inoculate the plant only through immature leaves, less than about one-quarter of their full length. The virus so inoculated does not pass out of the leaf until about 8 days have elapsed. On the basis of this knowledge a convenient and reliable single-leaf cage technique has been developed. After the virus has entered the stem it passes rapidly to the base of this stem, but odp slowly into side branches from it or into other stems arising from the same original cutting. Infection of a plant with a mild strain of virus failed entirely to confer immunity from infection by severe strains introduced by grafting. If the severe strains were inoculated by insects there was an indication of some conferred resistance but insufficient to make the procedure practically useful in control.Item Derris or Tuba Root(Taylor & Francis, 1940) Worsley, R.R.; Production in East Africa; A.R.C.S., AmaniActive interest has been shown for some time past in the trials being carried out with Derris elliptica at the East African Agricultural Research Station, ,Amani, where a particularly toxic strain of this Malayan fish-poison and insecticide was introduced, via Kew, in 1928. It is now possible to give the yield and cost of production figures for the first normal crop of derris root harvested at Amani, the bulk of previous crops having been used for experimental purposes, or cut as planting material, for which there is a considerable demand in East Africa at present.Item Strong Sweet Potatoes in Zanzibar(1945) Tidbury G. E.Unlike cassava, some varieties of which can be safely left in the ground for several months after the crop is ripe, sweet potatoes must be dug when the tubers are fully grown or rotting and insect infestation will rapidly destroy the crop. A further disadvantage of this crop in Zanzibar is that during the hot season, November to February, tuber formation does not take place even if the vines survive the hot, dry weather. There is thus a great shortage of sweet potatoes during the first half of each year. Some attention has, therefore, been given in this Protectorate to finding a simple method whereby the sweet potato can be stored for several months.Item Notes on Cassava Preparation in North Kavirondo and Samia(1944/1945) Anderson, G.W.; Department of Agriculture, KenyaInnumerable types of cassava are grown in the Samia and North Kavirondo areas, but of these, six are most generally popular mainly for the reason that they are, with one exception, early to medium in maturity and at the same time" sweet". That is to say they have not the strong bitter flavour of later maturing types—a bitterness which necessitates a longer method of preparation and which prevents the roots being used until they are almost fully developed. Of these popular varieties the earliest is Mbironyango, a variety introduced to the Bantus from Jaluo country, which matures in about eight months but which can be lifted and used in four. Next in order of maturity come four varieties which mature in about a year, but they also can be lifted early—anything from six months onwards. These are, Miti juma and Dodo, two varieties believed to have come in the first instance from the Uganda side of the border; Khasimbctsio and Namugassa, two locally named types which appear to have been in cultivation for several generations. Miti juma and Khasimbasio are two of the most common. The former for the reason that, although an early cassava, the roots can remain in the ground after reaching maturity for a period of up to three or four years without deterioration—a very popular characteristic in areas where the people are not prone to overexertion. Khasimbasio is popular for the reason that it yields quite heavily and, according to general belief amongst native growers, does not suffer to the same extent as other varieties from mosaic diseases.Item Long-Term and Short-Term Cassavas(July, 1944) Jameson, J. D.; Oates, C.; Muir, J. C.; Allnutt, T. B.; Nichols, R. F. W.; Department of Agriculture Kawanda, Kampala ,Uganda, Department of Agriculture Kenya, Department of Agriculture Tanganyika Territory, Department of Agriculture Zanzibar, Cassava Investigation of AmaniIt has been suggested here that correspondents to your journal might be able to throw light on a curious disparity in the practice of cassava cultivation between the various East African territories. In those parts of Uganda where cassava is an important reserve against famine it is the custom to plant up the greater part of the acreage with so-called "long-term" varieties. This description is perhaps not sufficiently definitive, but by it is meant varieties which stay in the ground for two or more years without appreciable deterioration to the tubers. The advantages of this course are presumably
