by Sam Delphin
Critical Review
“Human genetically-modified organism(s),” abbreviated as, “GMOs,” or, as labeled in this article, “transgenic agricultural crops,” first became technologically and commercially available some twenty years ago and have become the dominant varieties of many staple crops in the U.S., especially, corn, soybeans, and cotton. In 2014 the United States Department of Agriculture (USDA) published a thorough consideration of transgenic crops including detailed surveys and summarized field research. The experiences from the last twenty years are more ambivalent about the value of transgenic crops than when the transgenic concept was originally devised. Within the present context of cloned, transgenic crops, disestablished federal crop reserves, cursory inspections of imported foreign crops, and the reality of past U.S. homogenous-crop devastations from unanticipated vectors, U.S. agriculture appears highly vulnerable.
World Journal of Agricultural Research. 2017, 5(4), 240-243. DOI: 10.12691/wjar-5-4-6
Pub. Date: August 10, 2017
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by David Munyua Mutegi, Dora Kilalo, John Wangai Kimenju and Charles Waturu
Original Research
Tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has been an important pest in Kenya since it was reported in 2014. It is adversely affecting tomato production in the country. The objective of this study was to evaluate the pathogenicity of Kenyan EPNs namely;Heterorhabdities sp. andSteinernema karii againstTuta absoluta larvae under laboratory conditions in petri dish bioassays. Entomopathogenic nematodes were obtained from Kenya Agricultural and Livestock Research Organization EPNs laboratories and Tuta absoluta larvae were obtained from a colony reared and maintained in a greenhouse at Kabete Campus Field Station, Nairobi. The effect of EPNs concentrations onTuta absoluta larvae mortality exposed for 24-72 hours was evaluated. An experiment laid out in a complete randomized design with four replicates was conducted. The results showed that the evaluated concentration rates ofHeterorhabditis sp. andSteinernema karii at 100, 300 and 500 Ijs/ml significantly (p < 0.05) caused mortality on Tuta absoluta larvae compared to control and that the highest mortality was recorded at 500 Ijs/ml having been exposed for 72 hours. Steinernema kariiwas more pathogenic compared toHeterorhabditis sp.throughout the exposure period of 24-72 hours, having achieved 100% and 91.5% larval mortality, respectively. This study demonstrates that native EPNs have a potential for management of the tomato leaf miner (Tuta absoluta)which can be exploited.
World Journal of Agricultural Research. 2017, 5(4), 233-239. DOI: 10.12691/wjar-5-4-5
Pub. Date: August 09, 2017
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by Mireille Feudjio T, Peter Minang, Zapfack Louis, Serge Ngendakumana, Dieudonne Alemagi and Laliza Duguma
Original Research
Good understand of changes in shifting cultivation and factors involved is a way forward in finding appropriate respond to preserve forested landscapes. A study was conducted with the aim of analyzing different pathways that could be taken in shifting cultivation trajectories. A total of 470 households were randomly sampled in the three study sites of the southern part in Cameroon. Data were collected using household survey, focus group discussion, interview of key informants and remote sensing based analysis of land cover. We found that shifting cultivation could migrate from traditional to a relatively modern form. Modern form is characterized by the evolution of objective from consumption to commercialization, a very short fallow, improvement of technique, and introduction of new market crops and diversification of crops produced. It is affected by population density, availability of forest land and accessibly (road and transport). In the site where traditional form is observed, 88 % of respondents revealed that there is still forest land belonging to nobody where they can create new farm. Therefore, a good management of land will constraint shifting cultivators to shift to modern agricultural technique. Moreover, it is advisable to develop policy measures to promote the progressive change of this old practice towards the adoption of appropriate agricultural techniques in the context of preservation of forested landscape.
World Journal of Agricultural Research. 2017, 5(4), 221-232. DOI: 10.12691/wjar-5-4-4
Pub. Date: July 24, 2017
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by Jehad Abbadi
Original Research
The use of nutrient efficient alternative crops is a possible strategy of sustainable land use. Plant species vary in their phosphorous (P) use efficiency under suboptimal P supplies in different soils by using different strategies. Cultivating P efficient species to improve yields may be possible if P efficiency mechanisms are elucidated. Therefore P use efficiency of the alternative oil crops safflower and sunflower was studied under semi-controlled conditions in sandy and loamy soils using three P supplies. Both species responded strongly to increasing P supplies in both soils and performed better in loamy soil. In both soils, both species contained similar P concentrations in shoots at low P supplies, but safflower accumulated less P amounts in shoots than sunflower at all P levels. Sunflower had less external P requirements than safflower in both soils. Safflower had higher efficiency ratio than sunflower at low P supply in sandy soil, and less values in loamy soils. Safflower had lower utilization index than sunflower in both soils at all P levels. Safflower recovered less external P (added P, extractable-P, soil solution-P) than sunflower in both soils. The P use efficiency of crops is based on different competitive components. Neither safflower nor sunflower showed a combination of high values of all P use efficiency components in both soils at all P levels, but safflower was inferior to sunflower in most studied traits. Therefore safflower cannot be considered a low input species as compared to sunflower in terms of P uptake and utilization efficiency.
World Journal of Agricultural Research. 2017, 5(4), 212-220. DOI: 10.12691/wjar-5-4-3
Pub. Date: July 18, 2017
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by Elisabeth Simelton, Tham Thi Dao, An The Ngo and Tam Thi Le
Original Research
While the demand for climate-smart agriculture practices is rapidly growing in the 2010s, it remains vague in practice how to evaluate integrated farming systems, in particular. The study draws lessons learned from the My Loi climate-smart village, Ky Son commune, Ky Anh district, Ha Tinh province to explore the scalability potential to Ky Trung commune in the same district, and in the province. Specifically, we use mixed participatory field-based approaches to categorise current farming practices for the purpose of proposing context-specific climate-smart interventions, in addition to biophysical feasibility, policy support and expert consultations. Originating from local knowledge, five climate-smart agriculture models were derived with incremental implementation steps developed with technical expertise. While the specific components of the models are context-specific, the technologies and this improved approach for identifying CSA practices can be generically applied.
World Journal of Agricultural Research. 2017, 5(4), 200-211. DOI: 10.12691/wjar-5-4-2
Pub. Date: July 12, 2017
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by Mildred Millidee Morris, James W. Muthomi and John M. Wagacha
Original Research
High occurrence of root rots is attributed to continuous and inappropriate cropping systems, low soil fertility levels, low moisture in soil, use of farm saved seeds and use of root rot susceptible bean (Phaseolus vulgaris L.) varieties. This study evaluated the effect of soil fertility and intercropping on the incidence and severity of root rot diseases of common bean. Soil samples were collected at the start of the 2016 short rain cropping season to determine the soil nutrients status, and the incidence and population of soil borne fungal pathogens. The soil samples were analyzed for total nutrient status and pH levels. Soil borne fungal pathogens were isolated from the soil and stem bases by pour plate technique. Farm saved seeds of bean varieties KK8 and GLP2 were planted in field experiments at three sites in pure stand, intercropped with maize, applied with and without fertilizer. Data collected included seedling emergence, stand count, bean fly incidence, root rot distribution, incidence and severity, and yield. The pathogens isolated from soil and stem bases included F. oxysporum, F. solani, Pythium spp, Macrophomina and Rhizoctoniaspp, with Fusarium spp. being the most predominant at 40% incidence and mean population of 3000 CFU/g of soil. Bean intercropped with maize had 22% lower intensity of root rot compared to the sole crop. The findings of this study demonstrate that low soil fertility, use of farm saved seeds and high inoculum levels of soil borne pathogens in the soil contributed to the high incidence of root rots in the study sites. In addition bean varieties intercropped with maize had a 17% lower incidence of root rot pathogens compared to bean varieties from sole crop. It was observed that intercropping system reduces pests and diseases. However, root rot pathogens isolated from bean intercropped with maize had a significantly lower incidence than the sole crops.
World Journal of Agricultural Research. 2017, 5(4), 189-199. DOI: 10.12691/wjar-5-4-1
Pub. Date: June 08, 2017
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