Oviposition inhibitory activity of the Mexican sunflower Tithonia diversifolia (Asteraceae) polar extracts against the two-spotted spider mite Tetranychus urticae (Tetranychidae)

The Mexican sunflower (Tithonia diversifolia, Asteraceae) is an invasive shrub of agricultural and non-agricultural lands in tropical countries. Besides extensive utilizations in the traditional medicine, mainly to treat malaria, the plant is believed to have a great potential in agriculture of developing countries as a green biomass to produce fertilizer, fodder and biopesticides. The plant is known to produce tagitinins, which are sesquiterpene lactones with a bitter taste endowed with toxicity against several insects such as mosquitoes, aphids, and beetles. Here, we evaluated the potential of T. diversifolia against the two-spotted spider mite Tetranychus urticae (Tetranychidae), which is one of the most economically important arthropod pests worldwide. The leaf methanolic extract and its ethyl acetate fraction were tested for acute and chronic toxicity and for oviposition inhibitory effects. The chemical composition of the extracts was analyzed by HPLC-MSn and NMR. The main constituents were flavonoid derivatives, phenylpropanoids and sesquiterpene lactones. Among the latter, tagitinin C and tagitinin A were the major compounds. In acute toxicity assays, mortality did not exceed 50% even for the highest tested dose of 150 \u3bcg cm-3. However, in chronic toxicity assays, on day 5 from application, the methanolic extract LD50 was 41.3 \u3bcg cm-3 while LD90 was 98.7 \u3bcg cm-3. Furthermore, both T. diversifolia extracts inhibited oviposition in T. urticae. The ethyl acetate extract was the most active oviposition inhibitor, with an ED50 value of 44.3 \u3bcg cm-3 and an ED90 of 121.5 \u3bcg cm-3. Overall, the good yield rate of the extract and the high crop yield highlighted good prospects of using the extract from this plant for the development of oviposition inhibitors against mite

Mycorrhizas and biomass crops: opportunities for future sustainable development

Central to soil health and plant productivity in natural ecosystems are in situ soil microbial communities, of which mycorrhizal fungi are an integral component, regulating nutrient transfer between plants and the surrounding soil via extensive mycelial networks. Such networks are supported by plant-derived carbon and are likely to be enhanced under coppiced biomass plantations, a forestry practice that has been highlighted recently as a viable means of providing an alternative source of energy to fossil fuels, with potentially favourable consequences for carbon mitigation. Here, we explore ways in which biomass forestry, in conjunction with mycorrhizal fungi, can offer a more holistic approach to addressing several topical environmental issues, including ‘carbon-neutral’ energy, ecologically sustainable land management and CO2 sequestration

Agricultural Investment and Role of Commercial Farming in Benishangul-Gumuz Region: Evidence from Ethiopia

Agricultural investment remains the top strategy of the Ethiopian government to contribute to the national economy by changing the traditional farming to modern agriculture. In Benishangul-Gumuz regional state in the last two decades, a substantial amount of land has been transferred to domestic and foreign investors by both regional and federal governments. Hence, this study has aimed to generate information for better understanding of the system and the options available to promote the current agricultural investment and trend of agricultural investment to seize the challenges and harness the existing opportunities. The results revealed that found that the commercial farming is constrained by different factors; these includes lack of access to infrastructures (like electricity and irrigation facilities), unavailability of farm equipment (like combine harvester, thresher and cleaner), inadequate policy incentives, lack of access to improved crop varieties and livestock breeds, lack of access to market, low and volatile price of their produce, were mentioned among the others. On the other hand, availability of storage of grains, road, and mobile network access, ownership of tractor, fair interest rate and access to credit were mentioned as opportunities for the commercial farmers. Moreover, currently, commercial farming is contributing employment (temporary and permanent jobs) and marketing opportunities and income tax payment to the local community and the government. Therefore, we suggest that to tackle the challenges and seize the opportunities in commercial farming, quick government support in areas of infrastructure development, research and development and linking commercial farming with local and international markets is needed. Keywords: Agricultural Investment; technology; Benishangul-Gumuz DOI: 10.7176/JESD/10-3-0

Yield trends and yield gap analysis of major crops in the world

This study aims to quantify the gap between current and potential yields of major crops in the world, and the production constraints that contribute to this yield gap. Using an expert-based evaluation of yield gaps and the literature, global and regional yields and yield trends of major crops are quantified, yield gaps evaluated by crop experts, current yield progress by breeding estimated, and different yield projections compared. Results show decreasing yield growth for wheat and rice, but still high growth rates for maize. The yield gap analysis provides quantitative estimates of the production constraints for a number of crops and regions and reveals the difficulty to measure and compare yield potentials and actual yields consistently under a range of environmental conditions, and it shows the difficulty to disentangle interacting production constraints. FAO yield growth projections are generally lower than what possibly could be gained by closing current yield gaps

NIR Calibrations for Soybean Seeds and Soy Food Composition Analysis: Total Carbohydrates, Oil, Proteins and Water Contents

Conventional chemical analysis techniques are expensive, time consuming, and often destructive. The non-invasive Near Infrared (NIR) technology was introduced over the last decades for wide-scale, inexpensive chemical analysis of food and crop seed composition (see Williams and Norris, 1987; Wilcox and Cavins, 1995; Buning and Diller, 2000 for reviews of the NIR technique development stage prior to 1998, when Diode Arrays were introduced to NIR). NIR spectroscopic measurements obey Lambert and Beer’s law, and quantitative measurements can be successfully made with high speed and ease of operation. NIR has been used in a great variety of food applications. General applications of products analyzed come from all sectors of the food industry including meats, grains, and dairy products (Shadow, 1998)

Plant health sensing

If plants are to be used as a food source for long term space missions, they must be grown in a stable environment where the health of the crops is continuously monitored. The sensor(s) to be used should detect any diseases or health problems before irreversible damage occurs. The method of analysis must be nondestructive and provide instantaneous information on the condition of the crop. In addition, the sensor(s) must be able to function in microgravity. This first semester, the plant health and disease sensing group concentrated on researching and consulting experts in many fields in attempts to find reliable plant health indicators. Once several indicators were found, technologies that could detect them were investigated. Eventually the three methods chosen to be implemented next semester were stimulus response monitoring, video image processing and chlorophyll level detection. Most of the other technologies investigated this semester are discussed here. They were rejected for various reasons but are included in the report because NASA may wish to consider pursuing them in the future

NIR Calibrations for Soybean Seeds and Soy Food Composition Analysis: Total Carbohydrates, Oil, Proteins and Water Contents [v.2]

Conventional chemical analysis techniques are expensive, time consuming, and often destructive. The non-invasive Near Infrared (NIR) technology was introduced over the last decades for wide-scale, inexpensive chemical analysis of food and crop seed composition (see Williams and Norris, 1987; Wilcox and Cavins, 1995; Buning and Diller, 2000 for reviews of the NIR technique development stage prior to 1998, when Diode Arrays were introduced to NIR). NIR spectroscopic measurements obey Lambert and Beer’s law, and quantitative measurements can be successfully made with high speed and ease of operation. NIR has been used in a great variety of food applications. General applications of products analyzed come from all sectors of the food industry including meats, grains, and dairy products (Shadow, 1998).
Novel NIR calibrations for rapid, reliable and accurate composition analysis of a variety of several soy based foods and bulk soybean seeds were developed and validated in a six-year collaborative project with a large number of different samples (N >~12, 000). The availability of such calibrations is important for establishing NIR as a secondary method for composition analysis of foods and soybeans both in applications and fundamental research

Root systems of oilseed and pulse crops-morphology, distribution and growth patterns

This study determined the key characteristics of temporal patterns of root growth during the crop development period, as well as the vertical patterns of root distribution in the soil profile for important oilseed and pulse crops grown on the semiarid Canadian Prairie. Rooting characteristics greatly influence the nutrient acquisition and water-use patterns for any plants. However, crop root systems have not been studied intensively due to time, labor and costs constraints. In the literature, root studies mostly focus on cereal crops and very limited information is available for oilseeds and pulses even though these broadleaf crops are critical in the diversification of cropping systems. Thus the objectives of this study were to 1) examine the root morphological characteristics, root distribution patterns in the soil profile, and the fine root distributions of oilseeds and pulses in comparison with wheat; 2) to determine the rhizospheric properties of pulse crops. In 2006 and 2007, canola (Brassica napus L.), flax (Linum usitatissimum L.), mustard (Brassica juncea L.), chickpea (Cicer arietinum L.), field pea (Pisum sativumL., lentil (Lens culinaris), and spring wheat (Triticum aestivum L.) were grown under low- (natural rainfall) and high-water (rainfall+irrigation) conditions in southwest Saskatchewan. Roots were sampled at the seedling, early-flower, late-flower, late-pod, and physiological maturity growth stages, and root parameters determined using image analysis. The growth of roots progressed markedly from seedling to late-flowering and then declined to maturity. Root growth of pulse crops was not significantly affected by water conditions, but canola had 70% greater root length, 67% more root surface area, and 79% more root tips under high-water than under low-water conditions. At the late-flower stage, over 70% of the roots in oilseeds and pulses were distributed within the 0-60 cm soil profile and the largest proportion (around 50%) were found in the top 20-cm of the soil depth. About 85% of the roots in oilseeds and pulses were classified as “extra fine” (diamete

The Revolution of Mobile Phone-Enabled Services for Agricultural Development (m-Agri Services) in Africa: The Challenges for Sustainability

The provision of information through mobile phone-enabled agricultural information services (m-Agri services) has the potential to revolutionise agriculture and significantly improve smallholder farmers’ livelihoods in Africa. Globally, the benefits of m-Agri services include facilitating farmers’ access to financial services and sourcing agricultural information about input use, practices, and market prices. There are very few published literature sources that focus on the potential benefits of m-Agri services in Africa and none of which explore their sustainability. This study, therefore, explores the evolution, provision, and sustainability of these m-Agri services in Africa. An overview of the current landscape of m-Agri services in Africa is provided and this illustrates how varied these services are in design, content, and quality. Key findings from the exploratory literature review reveal that services are highly likely to fail to achieve their intended purpose or be abandoned when implementers ignore the literacy, skills, culture, and demands of the target users. This study recommends that, to enhance the sustainability of m-Agri services, the implementers need to design the services with the users involved, carefully analyse, and understand the target environment, and design for scale and a long-term purpose. While privacy and security of users need to be ensured, the reuse or improvement of existing initiatives should be explored, and projects need to be data-driven and maintained as open source. Thus, the study concludes that policymakers can support the long-term benefit of m-Agri services by ensuring favourable policies for both users and implementers

Biomass production, symbiotic nitrogen fixation and inorganic N use in dual and tri-component annual intercrops

The interspecific complementary and competitive interactions between pea (Pisum sativum L.), barley (Hordeum vulgare L.) and oilseed rape (Brassica napus L.), grown as dual and tri-component intercrops were assessed in a field study in Denmark. Total biomass production and N use at two levels of N fertilisation (0.5 and 4.0 g N/m2), were measured at five harvests throughout a growing season. All intercrops displayed land equivalent ratio values close to or exceeding unity, indicating complementary use of growth resources. Whereas both rape and barley responded positively to increased N fertilisation, irrespective of whether they were grown as sole- or intercrops, pea was strongly suppressed when grown in intercrop. Of the three crops barley was the strongest competitor for both soil and fertiliser N, rape intermediate and pea the weakest. Faster initial growth of barley than pea and rape gave barley an initial competitive advantage, an advantage that in the two dual intercrops was strengthened by the addition of N. Apparently the competitive superiority of barley was less strong in the tri-component intercrop, indicating that the impact of the dominantmay, through improved growth of both rape and pea, have been diminished through indirect facilitation. Interspecific competition had a promoting effect on the percent of nitrogen derived from N2 fixation of pea, and most so at the low N fertilisation level. Results indicate that the benefits achieved from the association of a legume and nonlegume, in terms of N2 fixed were greatest when pea was grown in association with rape as opposed to barley which could indicate that the benefits achieved from the association of a legume and nonlegume are partly lost if the nonlegume is too strong a competitor