Cover crops can be an important source of nitrogen (N) for organic vegetable production, but N availability depends on the characteristics of the cover crop residues and crop management practices following termination. A 2-year field experiment in Michigan investigated (1) how the proportion of cereal rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) sown in a cover crop mixture (seven treatments ranging from 100% rye to 100% vetch plus a no-cover-crop control) influences cover crop residue quantity and quality and (2) how rye-vetch residue characteristics and the use of black polyethylene mulch (PM) interact to affect soil N dynamics, crop quality, and yield in bell pepper (Capsicum annuum L.) and slicing cucumber (Cucumis sativus L.) production. Positive correlations among pepper marketable yield, leaf chlorophyll content (SPAD), and average soil inorganic N support that N fertility was a key driver of treatment effects. Higher sown proportions of vetch and the use of PM were generally associated with higher vegetable yields and soil N. The magnitude of yield response to PM was greater in a year with higher precipitation and greater for pepper than cucumber. Percentage of nonmarketable fruit decreased (pepper) and increased (cucumber) with PM. Pore water nitrate concentration below the root zone reflected plow layer N under PM but was more responsive to precipitation under bare ground. Our results demonstrate that PM can be an important tool for preserving N fertility benefits from high N cover crop residues for vegetable production, particularly on sandy soils.

The objective of this research is to assess the effects of the use of insect nets in vegetable production. To achieve this goal, data were collected in four departments of southern Benin (Mono, Couffo, Ouémé and Plateau) using an interview guide and a structured questionnaire. A total of 223 producers chosen at random from these areas where the CRSP Horticulture Project is located were surveyed. The results of the study show that growers using insect nets have not given up using chemical pesticides. However, a significant reduction in treatment frequencies was recorded in the nursery and after transplanting for most of the pesticides identified. Similarly, a significant reduction (more than 60.0%) in pest attacks (Helicoverpa armigera, Hellula undalis, Plutella xylostella, Bemisia tabaci and cochineals) was recorded among producers using anti-insect nets at 5%. These results involve that it is necessary to sensitize farmers to the use of nets to protect plants. This will significantly reduce pest attacks and reduce the use of pesticides in production. Key words: Anti-insect nets, effects, pests, market gardening, Benin.

A new soil water retaining technology, designed to increase vegetable production and improve water use efficiency (WUE), was field tested on sand soil. Green bell pepper (Capsicum annuum) and cucumber (Cucumis sativus) were planted on previously installed U-shaped troughs of impermeable membranes designed to double soil water content in plant root zones. These soil water retention technology (SWRT) membranes significantly increased volumetric water content (VWC) in plant root zones promoting both crop production and improved water use efficiency (WUE). Greater vegetable production was attained when SWRT membranes significantly increased the low 9% to 10% water holding capacity by control sands. Membrane improved VWC to 15% and 18% increased yields of green bell pepper by 20% and cucumber by 24%. These newly optimized root zone water contents also increased WUE 19% and 41% for cucumber and bell pepper crops grown on SWRT transformed sands. SWRT membrane installations also provide an early return on investment (ROI) for the sand soils that auto control optimal soil water contents in plant root zones. This new technology offers new opportunities for establishing greater profits for the long-term vegetable production on sand soils. Anticipated positive impacts by SWRT on natural resource management and crop production offers new opportunities for enhanced profitability while protecting the environment in rural America These SWRT improvements for vegetable production including greater yields, higher WUE, and very brief ROI should encourage adoption of this technology across irrigated vegetable production located on highly permeable sand and loamy sand soils.

Fruits and vegetables are important commodities in global agriculture. However, in sub-Saharan Africa, production is sub-optimal in terms of yield, quality and environmental health practices due to several constraints such as insect pests which reduce yields through direct damage, or indirectly as disease vectors often promoting microbial diseases. Pest control still relies mainly on chemicals with their associated risks of resistance selection and toxicity to humans and environment. Several alternatives including biopesticides, semiochemical and nets are being explored in pest management. Insect nets applied on tomatoes, cabbages, beans and leafy vegetables protect them from flies, butterflies, moths, albeit to a lesser extent, whiteflies, aphids and thrips reducing their outbreaks as compared to open cultivation. As a result, pest control is limited and yield quantity and quality are improved. Insect nets are safe and cost effective for a period of 3-5 years if well maintained, and they may be re-used and recycled. Insect nets applied on cabbages in Benin yielded 3-fold more profit than current practice. However, insect nets are not effective against all pests inclusion of insect attractants or repellents may enhance efficacy of netting technology. The use of insect nets offers a cost-effective insect pest management option to among smallholder vegetable growers. The full benefit will be achieved with intensified extension efforts to make this technology better known.

Tomatoes (Lycopersicon esculentum Mill) are one of the biggest vegetable crops in the world, supplying a wide range of vitamins, minerals and fibre in human diets. In the tropics, tomatoes are predominantly grown under sub-optimal conditions by subsistence farmers, with exposure to biotic and abiotic stresses in the open field. Whitefly (Bemisia tabaci Gennadius) is one of the major pests of the tomato, potentially causing up to 100% yield loss. To control whitefly, most growers indiscriminately use synthetic insecticides which negatively impact the environment, humans, and other natural pest management systems, while also increasing cost of production. This study sought to investigate the effectiveness of agronet covers and companion planting with aromatic basil (Ocimum basilicum L.) as an alternative management strategy for whitefly in tomatoes and to evaluate the use of these treatments ontomato growth and yield. Two trials were conducted at the Horticulture Research and Training Field, Egerton University, Njoro, Kenya. Treatments comprised a combination of two factors, (1) growing environment (agronet and no agronet) and (2) companion planting with a row of basil surrounding tomato plants, a row of basil in between adjacent rows of tomato, no companion planting. Agronet covers and companion cropping with a row of basil planted between adjacent tomato rows significantly lowered B. tabaci infestation in tomatoes by 68.7%. Better tomato yields were also recorded in treatments where the two treatments were used in combination. Higher yield (13.75 t/ha) was obtained from tomatoes grown under agronet cover with a basil row planted in between adjacent rows of the tomato crop compared to 5.9 t/ha in the control. Non-marketable yield was also lowered to5.9 t/ha compared to 9.8 t/ha in the control following the use of the two treatments in combination. The results of this study demonstrate the potential viability of using companion cropping and agronet covers in integrated management of B. tabaci and improvement of tomato yield.

Dans le but de diversifier le systeme de production de la tomate et reduire l'utilisation des pesticides au Sud Benin, trois modalites d'intensification a savoir : Avec taille en plein champ , Sans taille sous AgroNet et Avec taille sous AgroNet ont ete comparees a un temoin Sans Taille en plein champ . L'effet du filet AgroNet et de la taille sur la croissance et le developpement des plants, l'efficacite du filet vis-a-vis des ravageurs et maladies, l'incidence des oiseaux, les niveaux de rendements, la modification du microclimat et la rentabilite financiere de ces systemes ont ete evalues. Les resultats indiquent que l'intensification de la production agricole sous abri AgroNet augmente certes la temperature (de 4 a 6°C) et l'humidite relative (entre 70 % et 80 %). mais n'impacte pas negativement la croissance et le developpement des plants de tomate. L'utilisation du filet a permis de reduire significativement l'incidence des oiseaux. Des rendements commercialisables de l'ordre de 50 a 57 t/ha ont ete obtenus sous filet. Les marges nettes degagees sous filet sont plus elevees sur un marche bio (407 F CFA / Kg) que sur un marche conventionnel (7 F CFA / Kg). L'etude a permis de produire des tomates saines, sans risque de residus de pesticide. (Resume d'auteur)

If agro-ecological systems are to realize their potential as sustainable alternatives to conventional agricultural systems, innovation diffusion needs to be enhanced. We conducted surveys among 214 small-scale vegetable farmers in Benin, a food-deficit country in West Africa, on how they perceived the different attributes of eco-friendly nets (EFNs). The nets act as physical barriers against insects in vegetable production and so reduce pesticide use. Understanding farmer perceptions about new technologies helps reveal farmers’ propensity to adopt them. Intensity of attitude was measured on a Likert scale, and an ordered probit model was used to determine which characteristics of nets were most influential. Eighteen percent of farmers thought that EFNs would benefit them, but almost half preferred not to adopt this technology at all. The main reason for rejecting the nets was the perceived high labor requirement, particularly on larger plots of land. This largely negative perception was strongest among farmers with large areas cultivated with vegetables, farmers who had little or no experience in a trial, and those living far from extension services. We recommend expanded trials that engage a higher proportion of farmers, strengthening of external support for those wanting to use the nets and further technological development to reduce labor costs, improved access to finance and increased education about the negative impacts of insecticides abuse.

Substrate nutrient and moisture management are two major concerns in green roof agriculture, especially when using extensive systems, but there are currently no recommendations or best management practices. The purpose of this study was to explore three mulching strategies (pine bark, living sedum, and no mulch) and three fertilization regimens (25, 50, and 100g center dot m(-2) of 14-14-14N-P-K slow release fertilizer applied twice each growing season) over two growing seasons to determine their benefits to rooftop agriculture. Tomatoes (Solanum lycopersicum), beans (Phaseolus vulgaris), cucumbers (Cucumis sativus), peppers (Capsicum annuum), basil (Ocimum basilicum), and chives (Allium schoenoprasum) were grown. The 2010 crops outperformed those grown in 2011, likely because of the more extreme temperature and precipitation variations during 2011. When there were differences among mulch treatments, pine bark usually resulted in higher productivity than live sedum mulch. The effects of live sedum mulch on crop production were mixed, consistent with previous literature on the use of live mulches in agriculture. With the exception of whole plot, tomato, and cucumber grades, there was a positive dose response to fertilizer. Further research into more types of mulch, their effects on the green roof microclimate, and fertilizer composition and release rates is required.

CSA NewsVolume 60, Issue 2 p. 24-25 News & Perspective International Organic Conference in Long Beach Increases Collaboration among EU, U.S. Scientists Lise Andreasen, Lise Andreasen International Centre for Research in Organic Food Systems (ICROFS), DenmarkSearch for more papers by this authorEllen Mallory, Ellen Mallory University of Maine and ASA Organic Management Systems Community 2014 ChairSearch for more papers by this authorNiels Halberg, Niels Halberg ICROFS, DenmarkSearch for more papers by this authorMathieu Ngouajio, Mathieu Ngouajio USDA-NIFASearch for more papers by this authorKathleen Delate, Kathleen Delate Iowa State UniversitySearch for more papers by this author Lise Andreasen, Lise Andreasen International Centre for Research in Organic Food Systems (ICROFS), DenmarkSearch for more papers by this authorEllen Mallory, Ellen Mallory University of Maine and ASA Organic Management Systems Community 2014 ChairSearch for more papers by this authorNiels Halberg, Niels Halberg ICROFS, DenmarkSearch for more papers by this authorMathieu Ngouajio, Mathieu Ngouajio USDA-NIFASearch for more papers by this authorKathleen Delate, Kathleen Delate Iowa State UniversitySearch for more papers by this author First published: 03 February 2015 https://doi.org/10.2134/csa2015-60-2-13Read the full textAboutPDF 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. Volume60, Issue2February 2015Pages 24-25 RelatedInformation

Cabbage (Brassicaceae) is one of the most frequently consumed exotic vegetables in Benin and also the most affected by insects. To meet growing food demand, farmers rely heavily on synthetic pesticides that are harmful for themselves, consumers and the environment. Integrated pest management has been proposed as the means to improve vegetable productivity and quality in many developing countries. One approach is to substitute pesticides with physical barriers to insects, like nets. Here, we assess consumers' perceptions about cabbage and their purchasing behavior towards cabbage that was produced using these nets in two major cities in Benin. Results indicate that consumers are aware of the health risks associated with intensive use of pesticides but were not able to recognize the quality difference between cabbage produced under nets from those using pesticides. All consumers were willing to pay a price premium for cabbage with minimized pesticides residues compared with conventionally produced cabbage, the average premium being 38%. Women, older, highly educated consumers and those able to distinguish cabbage qualities were willing to pay the most. We suggest that farmers will obtain higher prices if their production of cabbage with preferred characteristics is accompanied by an improved marketing strategy.

Organic agriculture is one of the best developed multifunctional production strategies in agriculture, and yet is not widely understood in terms of its full potential for contributing to food security, economic development, and environmental health. This special edition of the journal Sustainable Agriculture Research explores the knowledge, innovations, potentials, and research needs that will strengthen the links between organic food systems, sustainable production, and enhanced ecosystem services. The following articles are from an international conference titled “Innovations in Organic Food Systems for Sustainable Production and Ecosystem Services,” held on 1-2 November 2014 in Long Beach, California. The conference was co-sponsored by the Organisation for Economic Co-operation and Development (OECD) Co-operative Research Programme on Biological Resource Management for Sustainable Agricultural Systems, the International Centre for Research in Organic Food Systems (ICROFS), the United Stated Department of Agriculture, National Institute of Food and Agriculture (USDA-NIFA), and the American Society of Agronomy (ASA).

In this study, low-cost pest exclusion nets (lcPENs) were evaluated to determine their efficacy in reducing pest infestation and enhancing yields of cabbage at KALRO Kabete and PTC (Practical Training Centre) Thika, Kenya, from March to September 2011 both at nursery and field production levels. Nets of two-mesh sizes (0.9 mm and 0.4 mm) were used whereby the 0.9 mm net was either impregnated or not impregnated with alpha cypermethrin to enhance efficacy through repellency effects of the pesticides. The lcPENs efficiency was compared with no-net use and grass shading (farmer practice) in a completely randomized block design with five replications. Results showed that diamondback moth (Plutella xylostella) larval infestation was lower (P<0.05) on cabbages covered with lcPENs both at nursery and field level. At nursery, aphids were lower (P<0.05) on seedlings covered with insecticide-impregnated lcPEN but in field conditions, there was no difference among the lcPENs. Cabbage yield was higher (P<0.05) on cabbages grown under lcPENs. The findings clearly demonstrate high incomes as a result of growing cabbages under lcPENs. However, there was no evidence of an increased role for insecticide impregnation except in the nets at nursery level. Hence farmers can use ordinary (un-impregnated) lcPENs for pest management in transplanted cabbage production.

Cabbage (Brassica oleracea var. capitata L.) is one of the most important vegetables in Kenya, mainly grown by smallholder farmers for food and source of income. Its production is hampered by insect pests and diseases, leading to economic yield losses. Row cover insect proof nets have been used in the past to manage insect pests of cabbage and were recently introduced to Kenya. This study planned to document disease incidence and severity levels on cabbage grown under insecticide impregnated Agronets as a tool to manage insect pests and microclimate. The study was conducted at KALRO-Kabete and PTC (Practical Training Centre)-Thika, Kenya both at the nursery and in the field. Treatments included 1) use of insecticide (alpha cypermethrin) impregnated Agronets with (0.9 mm mesh), 2) untreated 0.4 mm mesh Agronet, 3) grass shading as a farmer practice (at nursery) and 4) control where there was no Agronet use. The treatments had five replications in a completely randomized block design. Plots measured 2 x 6 m, with a 1 m path between consecutive plots and 2 m between consecutive blocks. Three major diseases were recorded: damping off (Rhizoctonia solani), downy mildew (Peronospora parasitica) and black rot (Xanthomonas campestris pv. campestris). Treatments showed significant (P<0.05) differences on severity of damping off, which was lowest on seedlings covered with Agronets compared with the other treatments at nursery. Comparably, the downy mildew disease severity was higher on seedlings covered with Agronets than those with no cover or shading at the nursery. The findings show that frequent disease scouting is crucial when using Agronets for cabbage pests management. This would allow farmers to take action when diseases are noticed. Further supportive studies to understand threshold limits that can trigger growers to employ disease control application may be needed. (Resume d'auteur)

The Fertilizer Use Efficiency (FUE) model separates the relationships among plant growth, herbivore nematode parasitism, nutrient deficiency and toxicity (Melakeberhan, 2006), and allows cross-disciplinary and integrated decision-making when amending soil. It calculates treatment outcome as a percent of control (untreated check) and graphically expresses data in four quadrants from best (A) to worst case (D) scenarios. The FUE model was modified to include assessment of beneficial nematodes and soil physicochemical properties in four quadrants (E, F-best case, G, worst case, and H, (Melakeberhan and Anvendaño, 2008). In order to fully assess soil health, the modification needs the power of integrating nematode functions. The objective of this study was to integrate weighted nematode guilds into the FUE model and test if the outcomes overlap with Quadrant F, which corresponds with Quadrant B of the Ferris et al. (2001) soil food web model. We tested the effects of plant and animal waste compost applied at 135, 203 and 270 kg N/ha to a processing carrot (Daucus carota) cv 'Cupar' field in 2012-2014. Urea and non-amended check were included as controls. Nematodes were extracted from soil samples collected at planting and harvest, enumerated and assigned to c-p 1 to c-p 5 groups. We adopted the Ferris et al. (2001) c-p value weighting for c-p 2 to c-p 5 nematodes and added weight for c-p 1 nematodes using the same formula, 0.8*(0.5*(n+1)) 2 where n is the c-p value and '0.5' is a fraction of increase in food web complexity with each increment in c-p class. This gives c-p value weighting of 0.2, 0.8, 1.8, 3.2 and 5 for c-p 1 to c-p 5, respectively. Weighted nematode guild abundance was calculated by multiplying the number of c-p group abundances with their respective c-p group weight and combined to form one value. The results were then fitted to the FUE model relative to soil organic matter (OM) and marketable carrot yield. Data points for OM and marketable carrot yield from animal and plant compost amendments appeared in quadrant F. This shows not only an improvement of the FUE model for soil health analysis, but integrates it with the soil food web model. The implications of this modification for much broader and cross-disciplinary analyses of soil conditions will be discussed.

Continuous coverage of vegetables with nets under different climate conditions in Benin and Kenya proved effective in protecting vegetable nurseries and main fields against key lepidopteran and dipteran pests. However, netting did not effectively protect the vegetables against small insects such as aphids and whiteflies, although a visual barrier could delay outbreaks. Hence, opening the nets during the day could be an alternative option to conserve the natural enemies for small insects. Moreover, the efficacy of the visual barrier may be complemented by a repellent compound impregnated in the net. The small-holder growers adopting the nets in Benin and Kenya have reduced the number of pesticide applications required by 70-100%. They have also increased the yield in quality and quantity of production due to microclimate modification. Cost-benefit analyses of the technology showed that with insect proof nets profitability rates of up to three times could be achieved when compared to the farmers' practices observed in the real environment. Hence, this technology could be a promising way to develop an agro-ecological approach for sustainable management of key horticultural crop pests.

Mixtures of cereal rye ( Secale cereale L.) and the legume hairy vetch ( Vicia villosa Roth) are used to provide fixed N in balance with other important cover crop services, but late planting and interference from rye can limit vetch productivity. This 2‐yr study in Michigan investigated how fall planting dates influence rye–vetch cover crop biomass quantity and quality in the spring, and evaluated whether staggering (delaying) rye seeding could improve vetch performance (biomass production, N fixation, and winter survival) in mixtures. Treatments consisted of a two‐way factorial of three vetch planting dates (late August, mid‐September, and late September) and three lengths of rye seeding stagger (co‐seeded, short stagger, and long stagger). Later planting of co‐seeded mixtures generally led to reduced total shoot biomass and lower proportions of vetch, resulting in cover crop residues with less vetch N and a higher total C/N. For earlier planting dates, delaying rye seeding until vetch emergence (short stagger) increased vetch shoot biomass by 760 to 1060 kg ha −1 (30–36 kg vetch N ha −1 ) relative to co‐seeding. Staggered seeding provided no benefit to vetch biomass at later planting dates, and delaying rye seeding until the vetch three to four leaf stage (long stagger) reduced vetch winter survival by 12 to 42% compared with co‐seeding. Additional research is needed to determine whether potential on‐farm benefits of rye–vetch staggered seeding justify the additional management complexity involved and possible tradeoffs with other cover crop services.