East African Agricultural and Forestry Journal最新文献

{"title":"Recovery of Ethylene Forming Enzyme from Green Pea Pods","authors":"C. Njoroge, E. Kerbel","doi":"10.1080/00128325.2004.11663412","DOIUrl":"https://doi.org/10.1080/00128325.2004.11663412","url":null,"abstract":"Ethylene Forming Enzyme (EFE) is the enzyme that catalyses the final step in the biosynthesis of ethylene (Kende, 1990; Yang etal., 1990; Yang and Hoffinan, 1984). The site of location of this enzyme in the plant cell is still unknown with certainty.' Mattoo and Lieberman (1977) suggested that it is localised in a cell wall-cell membrane complex. Bouzayen et al., 1990) suggested that there are two sites for EFE location in a plant cell. One of the sites is located on the plasmalemma and is very sensitive to plasmolysis of the cell, and the other site is in the tonoplast and its ethylene-forming ability is not affected by plasmolysis. These authors excluded the cell wall as a possible site for EFE location. Ververidis and John (1990) confirmed the findings of Bouzayens etal.; and also suggested that the actual EFE location depends on the stage of plant growth. Irrespective of the site of EFE location, it had been felt that it could only oxidise 1aminocyclopropane-carboxylic acid (ACC) to ethylene effectively if bound to the membrane, as its activity had not been recovered in vitro (John et al., 1985; Venis, 1984; Porter et al., 1986; Mayne and Kende, 1986). However, Ververidis and John (1991), fully recovered EFE activity in a cell free system from melon (Cucurnis melo) fruits. Other cell free systems have been reported to oxidise ACC to ethylene, but all the systems have a very high K,„ for ACC in the plant and this rules out the possibility of such systems being operative in the plant systems in-vivo because of their high Kin values for ACC. (McKeon and Yang, 1984; Stegink et al., 1986; Nielsen et al., 1984; Venis, 1984; Mayak etal., 1981).","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"5 1","pages":"1 - 6"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87895507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence of Bovine Abortion in Selected Areas of Central Uganda","authors":"A. Sekitoleko, F. Kasirye, R. Muwazi, O. D. Owiny","doi":"10.4314/eaafj.v68i3.1788","DOIUrl":"https://doi.org/10.4314/eaafj.v68i3.1788","url":null,"abstract":"Copyright © East African Agricultural and Forestry Journal, 2003. All rights reserved. This publication is accessible from http://www.eaafj.or.ke/","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"85 4 1","pages":"143 - 146"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84046010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Yield and Storage Quality of Improved Sweetpotato (Ipomoea Batatas [L.] Lam.) Cultivars in the Lake Victoria Basin, Kenya","authors":"B. A. Were, A. Onkware, S. Gudu","doi":"10.4314/eaafj.v68i4.1797","DOIUrl":"https://doi.org/10.4314/eaafj.v68i4.1797","url":null,"abstract":"Sweetpotato (Ipomoea batatas [L.] Lam.) is an important food crop in the tropics. In Kenya, it is mainly grown by small-scale fanners for food security during months of food scarcity. Nyanza Province produces 53% of the total national output (Irungu and Kidane-Mariam, 1992). Sweetpotato cultivation is common in the Nyatike and Mbita Divisions in the dry lowlands of Lake Victoria basin. The yield is low because of prevalent drought, weevil infestation and viral attack (Gudu and Were, 1996). The farmers in the two Divisions still grow land races in soils that are low in fertility, which further reduces the crop yield. Introduction of the high yielding, drought-tolerant cultivars that have been selected by the Kenya Agricultural Research Institute (KARI) and the International Potato Center (CIP) could improve yield. Apart from high yield potential, some of the cultivars are resistant to viral and pest attack (Mutuura et al., 1992).","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"11 4","pages":"197 - 204"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91462814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating Farmers' and Scientists' Knowledge in Participatory Soil Mapping and Management: A Case Study from Semi-Arid Eastern Kenya","authors":"P. Macharia","doi":"10.4314/eaafj.v69i1.1804","DOIUrl":"https://doi.org/10.4314/eaafj.v69i1.1804","url":null,"abstract":"ABSTRACT Sustainable natural resources management, particularly soil management, requires integration of farmers', researchers' and other stakeholders' knowledge for enhanced rural development. A field study was conducted by an interdisciplinary team of scientists in Kasikeu Sub-Location of Makueni District, Kenya, to assist in integrating farmers' and scientists' knowledge on soils in a participatory soil mapping. Gender-sensitive farmer group meetings, on-site discussions, transect walks, soil profile descriptions, and laboratory soil analyses were used for the study. The results of the study showed that farmers in Kasikeu mainly used soil surface characteristics such as colour, texture and coarseness to classify soils. Scientists on the other hand used the FAO/UNESCO Legend for the Soil Map of the World which lays emphasis on the characteristics of the subsoil. Further, at farm level, fanners know in detail the soil types, uses, and management of their soil after living and working on the soils for a long time. Scientists, on the other hand, acquire the knowledge on the soils in a relatively short time through soil survey, testing and classification. The analytical and other scientific data complements the farmers', knowledge on aspects that they cannot interpret. The women farmers have more detailed information on soils than men farmers, since the women are more involved in farming activities. Finally, the study showed that integration of indigenous knowledge provided by farmers and the scientific knowhow and facilities provided by the scientists underscored the fact that farmers and scientists need each other. In this way, scientists will be in a better position to identify the most appropriate agricultural interventions for improving soil productivity.","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"25 1","pages":"39 - 47"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89180767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparative Study of the Soils of the Upper Coalmeasure Residua Under Cropped-Grass-Forest Landcontinuum in Eastern Nigeria","authors":"C. Asadu, C.S. Bosah","doi":"10.4314/eaafj.v68i4.1798","DOIUrl":"https://doi.org/10.4314/eaafj.v68i4.1798","url":null,"abstract":"The soils of Nsukka in eastern Nigeria have generally been derived from the residua (disintegrated rock materials) of either Falsebedded Sandstone or Upper Coal Measure Formations (Asadu, 1990). These geological formations usually give rise to sandy and clayey soils (Akamigbo and Asadu, 1983). The Upper Coal Measures occupy the upper slopes and tops of residual hills in the area but residua from them are transported by colluviation or erosion processes to the lower plains to form soils of similar characteristics with those of the upper slopes. This study was carried out on soils derived from such colluvial materials. The selected sites were contiguous, hence land use was the only differentiating factor among the locations.","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"5 1","pages":"205 - 212"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75863230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Rates of Inorganic and Organic Fertilisers on Desmodium uncinatum Nodulation, Dry Matter and Seed Yields on Phosphorus and Nitrogen Deficient Soils","authors":"F. Muyekho, J. Mureithi, J. Ngeny","doi":"10.4314/eaafj.v69i2.1816","DOIUrl":"https://doi.org/10.4314/eaafj.v69i2.1816","url":null,"abstract":"ABSTRACT Forage legumes are important in the smallholder farming system since they increase the quality of livestock feeds and soil fertility through quality manure. The legumes can also concurrently enhance soil fertility through nitrogen fixation for companion grasses and subsequent cereal crops. Farmers in Kenya are aware of the importance of forage legumes but stunted/slow growth during the establishment year and non availability of low cost seed has limited adoption of this technology. Two experiments were carried out on nitrogen and phosphorus-deficient soils at the National Agricultural Research Centre Kitale. In experiment 1 the effects of nitrogen applied at the rates of 0, 10, 20, 40, 60, 80 and 100 kg N/ha were evaluated for nodulation and dry matter accumulation of Desmodium uncinatum. Experiment 2 evaluated the effects of 0, 23, 46, 69, 92, 115 kg P2O5/ha in the form of single superphosphate fertiliser and 10, 20, 30 and 40 t/ha of farm yard manure on nodulation, herbage dry matter and seed yields of Desmodium uncinatum. A randomized complete block design with 3 replicates was used in each experiment. Nitrogen fertilisers did not increase nodulation and dry matter yields significantly. Increasing nitrogen fertiliser rates beyond 20 kg N/ha resulted in a significant (P<0.01) decline in the total and number of effective nodules produced per plant. Herbage dry matter yields also significantly (P<0.01) declined with application of more than 40 kg N/ha. Application of 23 and 46 kg P2O5/ha significantly (P<0.05) increased nodulation (total and effective number of nodules) and herbage dry matter yields. However, for 2 years there was no advantage in applying rates exceeding 46 P2O5/ha. Farm yard manure also significantly (P<0.5) increased nodulation but there were no significant differences between application of 10 t/ha and higher rates of 20, 30 or 40 t/ha. Herbage dry matter yields were increased by application of farm yard manure though the results were not significant at P>0.05. Seed yields were not significantly increased by phosphate or farmyard manure application.","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"2 1","pages":"149 - 156"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90562497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the Interaction in Maize Cropping Density, Nitrogen and Soil Moisture with a Systems Simulator in Semi-Arid Machakos District, Kenya","authors":"G. Okwach, M. Siambi, C. Simiyu","doi":"10.4314/eaafj.v69i2.1817","DOIUrl":"https://doi.org/10.4314/eaafj.v69i2.1817","url":null,"abstract":"ABSTRACT The APSIM model was used to evaluate a range of maize densities on a sandy-clay loam at Kenya Agricultural Research Institute (KARJ)-Katumani Research Centre in Machakos and 2 contrasting farmers' fields situated on sandy and clay soil types. Each simulation was initialised with actual soil parameters measured at the time of commencing the run. Simulations on the Katumani soil were done under 5 contrasting Short Rainy i SR.) seasons of different rainfall regimes, namely SR1996 (185 mm), SR1995 (270 mm), SR1991 (328 mm), SR1992 (720 mm), and the El Nino season of SR1997 (958 mm). Maize densities used were 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 plants/m2. The model showed that maize grain yield declined as density increased under the poor 1996 season. Optimum crop density increased with seasonal rainfall, to reach 5.0 plants/m2 in the 1992 and 1997 heavy rainfall seasons. On the farmers' fields, APSIM showed that the clay soil out-yielded the sandy soil in high rainfall, while the reverse was true on poorer seasons. Simulations were done to determine the effects of varying nitrogen at constant crop density of 5.3 plants/m2. Nitrogen rates used were 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, and 120 kg/ha. The response of maize to N fertiliser varied with seasonal rainfall. Grain yields were depressed when N was added to maize during the poorer SR1996 and SR1995 seasons. With higher seasonal rainfall, APSIM predicted a sharp increase in grain yield at low rates of N. Simulations of the effects of N on maize yield on the 3 farmers' fields (clay and sandy soils) were done for SR1997 (1310 mm) and SR1998 (122 mm) seasons, using N rates of 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 kg ha. The model predicted crop failure for the SR1998 season on the clay soil throughout all levels of N rates. In the wet SR1997, grain yield was low at 0 to 30 kg N/ha, and then increased sharply at levels greater than 30 kg N/ha. The response to N was, therefore, highest in the clay soil under wet conditions. Grain yield responded well in the sandy soil during SR1997, though the rate of response was lower than in the clay soil. However, the sandy soil proved superior to clay in the poor season (SR1998). A gradual response to N was predicted in the sanity soil, up to 30 kg N/ha. Sowing date was more important for sandy than clay soil type. Delayed sowing on the clay soil type did not adversely affect yield, whereas a week's delay on the sandy soils led to a yield decline even in a favourable season.","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"87 1","pages":"157 - 171"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73489570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Manures Composted with High Quality Organic Residues on Dry Matter Accumulation, Nitrogen Uptake and Maize Grain Yield","authors":"F. Kihanda","doi":"10.4314/eaafj.v69i1.1806","DOIUrl":"https://doi.org/10.4314/eaafj.v69i1.1806","url":null,"abstract":"ABSTRACT Nitrogen is a major limiting nutrient in the maize-growing areas of central Kenya highlands. Due to the high cost of inorganic fertilisers, the majority of the farmers use farmyard manure (FYM) to improve crop productivity. However, FYM produced in the area is often of low quality particularly in terms of N concentration. Studies previously carried out in the region showed that composting FYM with different proportions of Tithonia diversifolia (tithonia) or Lantana camara (lantana) improved the N content of the manure considerably. This study was conducted to test whether composted manure would improve growth and yield of maize. A field trial consisting of seven treatments: FYM composted with tithonia (1:1 and 3:1 ratios), or lantana (1:1 and 3:1 ratios), FYM composted alone, inorganic N fertiliser and an absolute control was laid out in low N site. Maize (Zea mays cv. Hybrid 513) was the test crop. The treatments were arranged in a RCBD replicated 3 times. The various compost types and the inorganic fertiliser were applied at an equivalent rate of 100 kg N/ha. Above ground maize biomass was taken at 2, 6, 10, 14 and 18 weeks after crop emergence, dried to a constant weight and the N content determined. The plant N uptake for each period was calculated as a product of dry matter and N content in the maize tissue. Grain yield was adjusted to 13% moisture content. It was observed that dry matter yield, N uptake and final grain yield of maize were significantly higher in FYM composted with tithonia or lantana than the control or FYM composted alone treatments. Amongst the composts, the highest dry matter accumulation and N uptake was observed in FYM composted with tithonia at 1:1 ratio. Inorganic fertiliser treatments gave the highest dry matter and N uptake. Based on the growth and N uptake in the fertiliser treatment it was concluded that the N release in all the compost was lower than the crop demand.","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"33 1","pages":"63 - 68"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79840792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Organic Matter and Nitrogen Status of Manure on Smallholder Farms in Central Kenya","authors":"J. Wamuongo, A. Esilaba, J. Miriti, J. N. Mwangi, S. Kimani","doi":"10.4314/eaafj.v68i3.1787","DOIUrl":"https://doi.org/10.4314/eaafj.v68i3.1787","url":null,"abstract":"Mixed arable-livestock farming systems are common in central Kenya and manure from livestock is used as fertiliser in arable fields. However, increasing demographic pressure and intensification of agriculture has resulted in more continuous cultivation of arable lands without concomitant application of fertilisers. Continuous cultivation of land has resulted in accelerated soil nutrient depletion, decline in soil organic matter content, loss of physical structure and reduced crop productivity (Ikombo et al., 1994; Kilewe and Thomas, 1992).","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"42 1","pages":"135 - 142"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89817928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of High Energy Sorghums by Combining Ability Studies","authors":"S. Ganesh, A. Khan, N. Senthil","doi":"10.4314/EAAFJ.V68I4.1793","DOIUrl":"https://doi.org/10.4314/EAAFJ.V68I4.1793","url":null,"abstract":"High energy sorghums produce high alcohol content harvest with a considerable level of grain yield. Identification of superior hybrids with high alcohol content and grain yield is important (Selvi and Palnaisamy, 1987) for high-energy sorghum improvement. Ramalingam (1983) made genetic analysis of high energy sorghum for juice content and grain yield components. Selvi (1984) detected some of the superior cross combinations based on heterosis and combining ability studies. Assessment of combining ability for these traits will provide useful information for the selection of parents and hybrids based on general combining ability (gca) and specific combining ability (sca) effects. It also gives information on the nature of gene action governing the particular trait. The present study was conducted on 7 x 7 diallel cross for combining ability analysis to identify good combiners and superior for high energy.","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"15 1","pages":"169 - 172"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72796037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}