In an experimental trial in northern Nigeria, intercrops of okra ( Abelmoschus esculentus ) and pepper ( Capsicum annuum ) gave better yields and economic returns with application of 400 kg ha − 1 of inorganic fertiliser, 5 t ha − 1 of manure and 10-day irrigation intervals. Copyright © 2007 John Wiley & Sons, Ltd
The growth and yield parameters of 14 groundnut varieties were evaluated at three locations in Ghana, and key physical and nutritional characteristics of the grains were measured and compared. Kernel yields ranged from 940 kg ha −1 to 1463 kg ha −1 . Grain length and 100-grain mass were not consistently and strongly correlated, and the inconsistency may be partly due to differences in oil content, which has implications for processing of the different varieties. The protein content of the varieties ranged from 25.6% to 29.6% and many of the varieties would be suitable for dietary protein supplementation. No variety scored consistently highly for all characteristics, but varieties CSTV404MB and CS-49 grew very well, and had high protein contents and moderately high oil contents, so they can be recommended for oil extraction and protein supplementation of local diets low in protein. Copyright © 2008 John Wiley & Sons, Ltd
Methods for sweet potato storage, previously developed at a research station, were tested on-farm by subsistence farmers in Lake Zone, Tanzania. On-farm testing confirmed that the methods were suitable but indicated that practical and simple improvements were necessary, without which losses in the proportion of market-quality roots from the store could be as high as 79%. These practical improvements were mainly concerned with the position of stores on the farms. The addition of a new step, dehaulming, improved the recovery of market-quality roots by 48%. However, although the storage methods were developed in order to improve farmer income, most farmers said they would use the stored roots as a subsistence staple for household food security. Variations among the farmers in their attitudes to storing sweet potato suggest that, when transferring methods from the research station to the farm, it is necessary to target those most able to adopt the approach. Additionally, the farmers considered that local market traders may not be keen to sell stored roots. Therefore, other actors in the value chain, such as market traders and consumers, ought to be included in the process of transferring methods from the research station to the farm. Copyright © 2008 John Wiley & Sons, Ltd
Tapioca is a traditional product with great acceptability, especially in Brazil. As a starch-based food, its nutritional quality is limited to carbohydrates. The aim of this work was to evaluate the contribution of tropical fruit pulps and soy extract to tapioca's nutritional and sensory characteristics. The products were formulated with dried tapioca starch (63%) supplemented by acerola or mango fruit pulps or by soy extract in selected combinations (37%). The mixtures were homogenised and roasted for starch gelatinisation. The final product was submitted to vitamin C and protein determinations and sensory analysis (appearance, flavour, texture and overall acceptance). Vitamin C content of the acerola tapioca products was significantly increased. Protein content was increased by supplementation with soy but the absolute levels were still quite low. Acceptability by sensory attributes of formulated tapiocas was similar to, or in some cases higher than, the traditional product. Copyright © 2007 John Wiley & Sons, Ltd.
The changes that occurred in the reproductive system during the breeding season of the land snail Archachatina marginata ovum (Pfeiffer) were investigated from April to July 2005 in collections obtained from snail hunters. These changes were divided into four stages (juvenile stage, mating readiness, egg production and post reproductive), which are described. The observations on the changes in the reproductive organs of A. marginata ovum suggest that the adult population is vulnerable during the breeding season. Management guidelines that will enhance commercial production of the snails are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
A study was conducted in the semi-arid Mbeere district, Eastern Kenya, to determine spatial and temporal variability of crop yields and climatic factors and their impacts on sustainability of semi-arid agriculture. Spatial aspects were assessed by conducting a survey of on-farm crop yields and using a computer model (QUEFTS) to predict maize yields from soil chemical indices. Temporal aspects were studied using time-series data (rainfall, temperature and crop yields). The study did not find a significant correlation between farmers' actual yields and QUEFTS predictions, and soil nutrients were thus not the only factors influencing maize yields in the study area. Other yield-reducing factors (climate and management) not accounted for in the QUEFTS model played a role. Grain yields of staple food crops were highly variable, fluctuating in time and space, and suboptimal. Particular aspects of rainfall (e.g. the short rains, for cowpeas and beans) were more important than mean annual rainfall in determining crop yields, and factors other than rainfall and soil fertility apparently played a role. The observed low grain yields, large yield gaps and high rainfall variability challenge the sustainability of these farming systems. Copyright © 2008 John Wiley & Sons, Ltd
This study explored how sensory attributes and consumer acceptability of peanut butters varied with differing roasting times (40 to 55 min) and storage times (up to 48 weeks) for shelf-life testing. Quantitative descriptive analysis generated sensory terms that were appropriate to the local situation. Increased roasting time was associated with the sensory attributes brown colour, roasted taste and burnt taste. Consumer acceptance varied among consumers with two preferred roasting times of either 40 min (67% of consumers) or 50 min (23% of consumers). This was related to distinct peanut flavour profiles. During the storage study of five selected butters consumer acceptability did not alter with storage period. Sensory testing, however, was more sensitive to product changes: sensory attributes that varied with storage were sticky texture, stale odour and sweetness. Copyright © 2008 John Wiley & Sons, Ltd
Studies have shown that the fatty acid composition of oils consumed can affect the risk of cardiovascular heart disease, and many consumers are therefore looking for sources of ω-3 fatty acids. Three herbs of the family Lamiaceae, chia (Salvia hispanica L.), golden chia (Salvia columbariae Benth.) and winter savory (Satureja montana L.), all of which produce seeds rich in ω-3 fatty acid, were planted in northwestern Argentina to determine their production potential in terms of seed yield, oil content and fatty acid composition. Chia seed had the highest oil content (29.9%), followed by golden chia (21.0%) and winter savory (8.0%). All three crops exhibited similar fatty acid profiles, with α-linolenic ω-3 fatty acid being the largest component. Golden chia had the highest α-linolenic fatty acid content: 17% and 11% more than chia and winter savory, respectively. Golden chia's shattering, however, is a major disadvantage for commercial production, making this the least attractive crop of the three. Copyright © 2008 John Wiley & Sons, Ltd
Supplementing the tef (Eragrostis tef) straw feed of Arsi oxen (Bos indicus) with 1, 2 or 4 kg per animal per day of noug (Guizotia abyssinica) meal for 90 days improved growth parameters. Supplementation significantly increased feed intake, average daily gain, and the weight of dressed carcass and lean meat. Supplementation with 1 kg of noug meal was the most profitable, giving a net return per animal of US$17.10, whereas a sole diet of tef straw gave a loss of US$18.66 per animal. Copyright © 2007 John Wiley & Sons, Ltd
Inheritance of resistance in cowpea to Clavigralla tomentosicollis Stål was studied on F 1 , F 2 and F 3 generations produced from crosses made between Ife Brown, a susceptible cultivar (P S ), and TVu 3354, a resistant variety (P R ), on the pods of which freshly emerged nymphs of C. tomentosicollis were caged. Nymphal weight gain was significantly higher ( p < 0.05) on P S . There were no significant differences between the weight gains of nymphs that fed on F 1 , F 2 and F 3 pods. Insect mortality was significantly higher on P R (86.7%) and the F 2 (70.0%) generation. Total nymphal development period was significantly longer on P R (15.0 days) while that on F 1 and F 2 generations was significantly longer than on the F 3 generation. Nymphal survival and adult emergence were observed on eight plants out of 60 and 19 plants out of 80 from the F 2 and F 3 generations, respectively. Broad-sense heritability estimates were 90.3% and 94.3% for the F 2 and F 3 generations, respectively. The results clearly indicated that TVu 3354 has highly heritable resistance to C. tomentosicollis . Copyright © 2008 John Wiley & Sons, Ltd
White cassava roots (bitter variety), plantain stems (‘Afoto’ variety) and yam tubers ( Dioscorea alata ‘Florido’) were stored for 28 days after harvest in the laboratory in ambient conditions (28°C). The changes in their nutritional properties (moisture, acidity, protein, lipid, carbohydrate, total sugar, ash and calorific value) were studied after different periods of storage. The nutritional changes of the three commodities were described and compared. Cassava and green plantain could be kept for a week without significant deterioration but showed progressive deterioration thereafter, while yam tubers underwent only slight changes over the total 4-week storage period. Copyright © 2007 John Wiley & Sons, Ltd
This study examined: the marketing costs, margins and returns of retailed beef meat in southeast Nigeria; factors influencing the traders' net returns; problems associated with marketing of beef; and the socio-economic characteristics of respondent traders. Sixty respondents were selected at random, with 20 respondents from each of three purposively selected markets in the study area. A structured interview schedule and personal observations were sources of primary data. The field data were analysed using cost-return principles, multiple regression analysis and descriptive statistics. The gross margin for trading was
We assessed substrate-induced respiration and soil chemical properties in order to study the influence of charcoal, nitrogen and phosphorus fertilisation on two different perennial crops in a confounded factorial design on a highly weathered Amazonian upland soil. Each plantation tested three different factors in three different levels making up 27 (3 3 ) treatment combinations. Whereas the banana plantation received mineral fertilisation in addition to charcoal applications (3 rd factor), the guarana (Paullinia cupana) plantation was fertilised organically using chicken manure and bone meal as the corresponding factors. Charcoal increased pH, total nitrogen, availability of sodium, zinc, manganese, copper and soil humidity, and decreased aluminium availability and acidity in the mineral-fertilised plantation only. This caused a significant increase in basal respiration and microbial efficiency in terms of carbon dioxide release per microbial carbon in the soil. The microbial biomass, efficiency and population growth after substrate addition was significantly increased with increasing levels of organic fertiliser amendments. We conclude that charcoal is a valuable component especially in inorganic-fertilised agricultural systems. Copyright © 2008 John Wiley & Sons, Ltd
Tropical ScienceVolume 47, Issue 1 p. 1-2 EditorialFree Access Preserving the best, reviewing the rest Chris Haines, Chris Haines EditorSearch for more papers by this author Chris Haines, Chris Haines EditorSearch for more papers by this author First published: 12 March 2007 https://doi.org/10.1002/ts.193AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume47, Issue1March 2007Pages 1-2 RelatedInformation
The aim of this study was to evaluate milk production and reproductive performance of Sahiwal cattle in semi-arid Kenya. Milk production traits considered were lactation milk yield, lactation length and test-day milk yield, while reproductive traits included age at first calving, calving interval and number of services per conception. Various fixed effects affected performance of milk production and reproductive traits to varying significance levels. The mean estimates for milk production traits were 1368 kg, 282 days and 4.9 kg for lactation milk yield, lactation length and test-day milk yield, respectively. For reproductive traits, mean estimates were 468 days, 2.2 and 1345 days for calving interval, number of services per conception and age at first calving, respectively. There was a decline in lactation milk yield and lactation length, and an increase in calving interval and age at first calving over the years. Satisfactory management and appropriate genetic improvement strategies would result in improved performance. Implications of the results for genetic improvement of the breed in Kenya are discussed. Copyright © 2007 John Wiley & Sons, Ltd
Surveys were made of major seed-borne fungi associated with seeds of common bean (Phaseolus vulgaris L) in different bean-growing areas of Ethiopia. Field and laboratory experiments were also carried out during the 2003 and 2004 crop seasons to study the survival and transmission of bean anthracnose pathogen Colletotrichum lindemuthianum to the seedlings. The major seed-borne fungi associated with common bean seeds were Colletotrichum lindemuthianum, Phaeoisariopsis griseola and Ascochyta phaseolorum. Bean anthracnose survived in infected seeds but not in the soil, and the primary source of bean anthracnose infection in the field was from infected seeds. Seed infection of common beans by bean anthracnose resulted in both pre-emergence and post-emergence mortality of bean seedlings. A significant positive relationship was found between the levels of primary seed infection and seedling infection in the field. Further development of bean anthracnose in the field was influenced by weather variables (rainfall, number of rainy days, humidity and temperature). Copyright © 2007 John Wiley & Sons, Ltd
Based on household-level data gathered from 115 randomly selected rural locations in Dire Dawa, the extent of food security and livelihoods strategies was scrutinised. Food insecurity was found to be a severe problem in the area with 76% of the households being food insecure, and with a food-insecurity gap and severity of food insecurity of 31% and 15%, respectively. The study also identified various livelihood strategies of the rural households, which were found to be a composite of different activities to enable them to make a living. These activities included mixed crop-livestock farming, diversification of crop production, diversification of livestock production, and supplementation of crop and livestock production with off-farm activities. Copyright © 2007 John Wiley & Sons, Ltd
Rice samples mildly parboiled at various combinations of soaking temperatures and steaming times were analysed for their thiamine and riboflavin contents. The relative parboiling index was calculated and this provided a reliable measure of the overall effects of different conditions on the degree of parboiling. The thiamine content of parboiled rice samples increased gradually as parboiling intensity was increased from initial soaking temperature at 30°C and steaming for 4 min to soaking at 70°C and steaming for 12 min. There was a sharper rise in thiamine when the soaking temperature was increased to 90°C, and the sample that was steamed for 12 min after soaking at 90°C had a thiamine content of 0.612 µg g −1 . The level of riboflavin also initially increased with parboiling, but it peaked at 0.278 µg g −1 in the sample that was soaked at 70°C and steamed for 12 min, and then decreased as parboiling intensity was increased further. The commercially parboiled rice sample had a riboflavin content of 0.206 µg g −1 . This pattern of change in riboflavin levels with parboiling was probably due to thermal breakdown of the vitamin at higher soaking temperature. Copyright © 2008 John Wiley & Sons, Ltd
Two sets (white- and yellow-kernelled) of six cultivars of field-maize, each comprising three hybrids and three open-pollinated (OP) varieties, were evaluated for green-maize productivity under three levels of nitrogen fertilisation (0, 60 and 120 kg ha−1) at two locations in southwestern Nigeria. The relationship between green-maize and grain yield was also investigated. Numbers of marketable ears and marketable-ear yield were significantly correlated. Green-maize traits and grain yields showed different responses to increased nitrogen fertiliser application: grain yield was significantly greater at 120 kg ha−1 than at 60 kg ha−1 whereas marketable-ear yield was not significantly changed by the higher rate. The hybrids showed higher green-maize and grain yield responses than the OPs to fertiliser application. At 60 kg ha−1 nitrogen application, marketable-ear yield averaged 0.620 kg m−2 and 0.567 kg m−2 for white hybrids and OPs, respectively, and 0.576 kg m−2 and 0.439 kg m−2 for yellow hybrids and OPs. Marketable-ear yield was significantly correlated with grain yield for both the white and yellow cultivars. Regressions of grain yield on marketable-ear yield were significant and such regression equations can thus be used to estimate marketable-ear yield potential from grain yield data. Copyright © 2008 John Wiley & Sons, Ltd
A virus, 750 × 18 nm, was isolated from Centrosema pubescens from Nigeria, causing leaf malformation, mosaic and mottling on the plant. When inoculated on to various test plants, it failed to produce necrotic or chlorotic lesions on Chenopodium amaranticolor , but symptoms of mottling were observed. The virus did not infect cowpea ( Vigna unguiculata varieties IT82E-10, IT84S-2114, Ife brown, TVU 76 or TVU 2657), but produced chlorotic spots, vein clearing and mottling on soybean ( Glycine max cultivars Malayan and Samsoy-2). Protein-A sandwich enzyme-linked immunosorbent assay (ELISA) shows that the virus is serologically closely related to Sweet potato feathery mottle virus (SPFMV) genus Potyvirus , Bean yellow mosaic virus (BYMV) genus Potyvirus and Tobacco etch virus (TEV) genus Potyvirus . Comparison of amino acid sequences of the coat protein of the virus with several potyvirus coat protein sequences, using BLAST (Basic Local Alignment Search Tool) analysis, confirmed the relationships. The antiserum raised against the virus had a titre value greater than 1 : 16,000, using antigen-coated plate ELISA. The name Centrosema mosaic virus (CenMoV) for this apparently new Potyvirus is suggested. The consequences of infection of forage legumes with this virus are discussed. Copyright © 2007 John Wiley & Sons, Ltd
