Organic Tomato Production Research Articles

Greenhouse study and interviews indicate glyphosate residue via feed-feces-fertilizer route is a risk for horticultural producers using manure-based fertilizer

BackgroundThe herbicide glyphosate is the most widely used active ingredient in pesticides globally. Residues have been found in people, livestock, food and animal feed, and in the environment, but little is known about glyphosate residue in manure-based fertilizer. We describe a feed-feces-fertilizer route of glyphosate contamination with negative impacts for horticultural production. This exposure can harm sensitive plants, such as tomato, and pose a risk to effective waste disposal and nutrient cycling along principles of the circular economy.We review the use and history of glyphosate and present a mixed methods research based on a real-world case from Finland where glyphosate residue in poultry manure fertilizer was suspected of inhibiting commercial organic tomato production. To test the fertilizer, we grew 72 ‘Encore’ variety tomato plants for 14 weeks in a climate-controlled greenhouse according to the practices of the commercial grower. To ascertain awareness and potential contamination mitigation measures, we contacted five fertilizer companies with sales of biogenic fertilizer in Finland, two farming organizations, a feed company, and two government organizations working on nutrient cycling and agricultural circular economy.ResultsThe total harvest of tomatoes grown with fertilizer with the higher content of glyphosate residue was 35% smaller and the yield of first-class tomatoes 37% lower than that of the control, with lower glyphosate concentration. Two of the five fertilizer companies identified poultry manure as a source of glyphosate contamination. Companies with awareness of pesticide residues reported interest in establishing parameters for pesticide residues.ConclusionsThe extent of glyphosate contamination of recycled fertilizers is unknown, but this study shows that such contamination occurs with negative impacts on crop production. Lack of testing and regulation to ensure that recycled fertilizers are free from harmful levels of glyphosate or other pesticides creates risks for agricultural producers. The issue is particularly acute for certified organic producers dependent on these products, but also for sustainable transitions away from mineral fertilizers in conventional farming. The example from Finland shows that a model of co-production between fertilizer producers and state regulatory agencies to establish safe limits can benefit both fertilizer producers and their customers.

COMPARING THE ECONOMIC EFFECTS OF OPEN FIELD AND PROTECTED AREA ORGANIC TOMATO CULTIVATION SYSTEMS

To compare the economics of different systems of organic tomato production, two models were created, one assuming outdoor production, and the other representing production in a protected area under a greenhouse, based on the data obtained through interviews with organic tomato producers from Vojvodina. The cost and sensitivity analysis revealed that the greenhouse model yields better results overall (a financial result of €273/100 m2 compared to €58/100 m2), despite the higher costs due to amortization, interest and costs related to the higher yield obtained. The production model also showed less dependence on the change in organic tomato yield and price, as well as key cost groups and post-harvest losses, which in both cases were mediated by growing coriander as an intercrop. This research improves the knowledge of the economics of organic tomato cultivation and at the same time proposes a methodology to analyze the economic impact of other organic productions.

Development of Menthyl Esters of Valine for Pest Control in Tomato and Lettuce Crops.

Menthyl ester of valine (MV) has been developed as a plant defense potentiator to induce pest resistance in crops. In this study, we attempted to establish MV hydrochloride (MV-HCl) in lettuce and tomato crops. When MV-HCl solutions were used to treat soil or leaves of potted tomato and lettuce plants, 1 µM MV-HCl solution applied to potted plant soil was most effective in increasing the transcript level of defense genes such as pathogenesis-related 1 (PR1). As a result, leaf damage caused by Spodoptera litura and oviposition by Tetranychus urticae were significantly reduced. In addition, MV-HCl-treated plants showed an increased ability to attract Phytoseiulus persimilis, a predatory mite of T. urticae, when they were attacked by T. urticae. Overall, our findings showed that MV-HCl is likely to be effective in promoting not only direct defense by activating defense genes, but also indirect defense mediated by herbivore-induced plant volatiles. Moreover, based on the results of the sustainability of PR1 expression in tomato plants treated with MV-HCl every 3 days, field trials were conducted and showed a 70% reduction in natural leaf damage. Our results suggest a practical approach to promoting organic tomato and lettuce production using this new plant defense potentiator.

Novel Potential of Rose Essential Oil as a Powerful Plant Defense Potentiator.

Terpenoids, natural compounds released by plants, function to enhance plant defense. The aim of this study was to investigate the effects of terpenoid-enriched essential oils (EOs) on tomato plants. From the application of a highly diluted solution of 11 different EOs to potted tomato soil, our study showed that rose essential oil (REO), rich in β-citronellol, played a crucial role in activating defense genes in tomato leaves. As a result, leaf damage caused by herbivores, such as Spodoptera litura and Tetranychus urticae, was significantly reduced. In addition, our results were validated in field trials, providing evidence that REO is an effective biostimulant for enhancing plant defense against pests. Notably, the REO solution also had the added benefit of attracting herbivore predators, such as Phytoseiulus persimilis. Our findings suggest a practical approach to promote organic tomato production that encourages environmentally friendly and sustainable practices.

Plant Growth, Fruit Yield, and Tomato Leaf Curl Disease of High Tunnel Organic Tomato Affected by Shade Net and Plastic Mulch Color

There is an increasing interest in producing organic tomatoes (Solanum lycopersicum) in high tunnels (HTs) in the southeast United States. HTs are unheated, passively cooled structures that allow tomato growers to harvest high-quality fruit out of season. However, excessive temperatures inside HTs may negatively impact tomato plant growth and fruit yield. Shade nets have been reported to reduce temperatures inside the HTs. Plastic mulch color has also significantly influenced plant growth and yield under high-temperature conditions. This study aimed to determine the effects of shade net color and plastic mulch color on plant growth, fruit yield, and incidence of tomato yellow leaf curl disease (TYLC) in ‘Red Snapper’ tomato grown in HTs under elevated temperatures (summer-fall) in southern Georgia, USA. Organic ‘Red Snapper’ tomato seedlings were transplanted in HTs in 2019 (Season 1) and 2020 (Season 2). The design was a split-plot randomized block where the main plots were externally mounted shade nets (black, silver, and unshaded; 30% shade factor), and the subplots were plastic mulches (black and white). Compared with black mulch, white mulch improved plant height and stem diameter but did not influence fruit yields. Shade nets reduced HT air temperature and root zone temperature (RZT) but did not affect plant height and stem diameter. The diminished photosynthetic photon flux density (PPFD) under the shade nets reduced marketable fruit yield. Thus, shade nets are not recommended once heat challenges do not limit HT tomato production in Georgia (after about mid-October). Shade nets and plastic mulch inconsistently affected TYLC incidence, severity, and area under the disease progress curve (AUDPC). Additional fruit yield reductions occurred due to TYLC because the incidence was 100% 6 weeks after transplanting. Preliminary insect data showed that shade net treatments had similar sweetpotato whitefly (Bemisia tabaci) numbers. The high TYLC incidence indicates that ‘Red Snapper’ may not be suitable for fall HT tomato production in the southeast United States. More research on shading and heat stress management in HT organic tomato production is necessary.

Multiple eco-efficiency solutions in tomatoes simulating biostimulant effects

Global agricultural systems are increasingly moving towards organic farming to satisfy consumers’ increased environmental awareness. Yet, shortage of fertilizers and more frequent water stresses are challenging agricultural systems to minimize their environmental impact without compromising productivity and economic sustainability. This study discusses how greenhouse organic tomato production behaves when multiple eco-sustainable solutions are applied. In particular, organic tomato cultivation was supported by a specific biostimulant treatment that included a microbial solution, based on Rhizobium, which was distributed onto faba bean seeds; once a suitable fava bean biomass had been obtained, the plants were chopped and incorporated into the soil in order to release nitrogen. In the trials considered, microbial solutions reduced organic tomato production costs by 5 %. Considering that fertilization accounted for up to 7 % of total production costs, a large-scale preparation of the microbial solution could trigger significant economic savings. The Life-Cycle Assessment shows that organic tomatoes, with a lower yield, have a lower environmental impact than conventional production only for 7 of the 15 evaluated impact categories. Combined agro-technical growing solutions are economically viable in the presence of yields in organic compared to conventional, and their environmental impact is attractive in both scenarios.

Nutrients Uptake and Fruit Yield of Tomato (Lycopersicon Esculentum Mill.) Produced Using Home Sorted and Municipal Organic Materials as Nutrient Sources.

Tomato (Lycopersicon esculentum Mill.) is one of the most popular crops with a unique role in human diets especially in Nigeria. Nutritional quality of fruit is a reflection of uptake by the plant. The study investigated the uptake of Nitrogen, Phosphorus, Potassium, Calcium and Magnesium uptake by tomato with incorporation of home and municipal sorted solid waste. Screenhouse experiment was carried out at the College of Plant Science and Crop Production, while field experiment was conducted at the Directorate of University Farms, Federal University of Agriculture (Latitudes 7°13ʹN and 7°20ʹN and Longitudes 3°20ʹE and 3°28ʹE) during the early and late seasons of 2019. Roma VF and Ibadan-local varieties as test crop. The screenhouse experiment was factorial in Completely Randomized Design. The treatments were: composted municipal solid waste; composted home sorted waste; pyrolyzed municipal solid waste and pyrolyzed home sorted waste at the rate of 0, 5, 10 and 20 tha-1 each. The field experiment was set up in a randomized complete block design with incorporation of waste treatments at 10 t ha-1, all in three replicates. The treatments mentioned above for screenhouse were also used for field experiment. Data collected were subjected to Analysis of Variance and the means were separated using Duncan’s Multiple Range Test (p<0.05). The study was carried out in the wet and dry seasons. Nutrients (N, P, K, Ca and Mg) uptakes by plants were determined after laboratory analysis using nutrient concentration x dry matter (kg ha-1). Treatments had significant effects on the fruit yield of tomato. Composted home sorted waste at 5 t ha-1 resulted in highest uptake of nitrogen (5.32 mg kg-1), phosphorus (2.87 mg kg-1), potassium (26.10 mg kg-1) and magnesium (9.74 mg kg-1) in screenhouse compared with control and other treatments. Pyrolyzed wastes enhanced the fruit yield and nutrient uptake by plant relative to composted wastes in both seasons on the field. Pyrolyzed home sorted waste (PHSW) enhanced nitrogen uptake at early (186 kg ha-1) and late (108 kg ha-1) seasons. Pyrolyzed wastes (PHSW and PMSW) increased phosphorus uptake of 573 kg ha-1 and 507 kg ha-1 respectively in the early season while the highest phosphorus uptake of 339.6 kg ha-1 was observed with PHSW in the late season. Pyrolyzed municipal solid waste (PMSW) increased potassium uptake in both early (22.21 kg ha-1) and late (12.55 kg ha-1) seasons compared to control and other treatments applied. It was concluded that composted and pyrolyzed home sorted wastes improved the fruit yield and nutrient uptake in organic tomato production, and thus recommended for optimal production of tomato.

Inoculação com fungo micorrízico arbuscular Rhizophagus clarus em tomateiro proporciona aumento de produtividade em cultivo orgânico

ABSTRACT: Organic agriculture comprises farming practices that discard synthetic pesticides and fertilizers. Tomato production demands huge amounts of fertilizers and pesticides. Improving efficiency of the inputs allowed for organic tomato production is a challenge to upgrade yields. Thereby, we studied the effects of the inoculation of the arbuscular mycorrhizal fungus (AMF) Rhizophagus clarus, supplying rock thermophosphate and bioactivator, alone or associated, on tomato development and yield. The experiment was achieved in a greenhouse using undetermined tomato cv. BRS-Nagai sown in polystyrene trays and afterwards transplanted to pots. Treatments included R. clarus; thermophosphate (TH) (130 g/pot); bioactivator (PenergeticK® + Penergetic®) (BI); R. clarus + TH; R. clarus + BI; R. clarus + TH+ BI and TH + BI and control (CO). From the flowering onset, plant height, height of insertion of first truss, trusses space, length, and also the diameter and fresh weight of ripe fruits of the three first trusses were assessed. AMF colonization in the roots and macronutrients in leaves and petioles were also measured. Trusses spacing variable was affected by mycorrhiza and thermophosphate. R. clarus inoculation incremented 10 and 31.85% of fresh mass of ripe fruits and mass of ripe fruits per plant, respectively. Soluble solids contents in fruits and N, P and K in the leaves and petioles were similar among treatments. AMF colonization decreased on thermophosphate fertilized plants and increased in bioactivator treatment. Results showed that root inoculation with R. clarus promoted better plant development and yield and may be used as biological inoculant mostly on organic tomato production.

Environmental impact of Danish organic tomatoes grown in greenhouses: Quantifying the reduction potential from changes in energy supply towards 2030

The demand for organic food products, including tomatoes (Solanum lycopersicum, L. 1753), is growing. Heated greenhouse production is well described through life cycle assessment (LCA), but inventories reflecting organic production conditions are inadequate or missing. At the same time, energy systems in Europe are changing, which is expected to have a considerable impact on the emissions from the energy intensive greenhouse production. Thus, this study is assessing the current environmental impacts using LCA of an organic tomato production in a heated greenhouse, and estimate the expected changes to impacts due to changes in energy supply. The assessment is based on activity data from a commercial greenhouse production. Current organic tomato production where plants are transplanted into the greenhouse in the late winter has impacts of 1.06 kg CO2 eq., 7.22 × 10−4 N eq., 3.49 × 10−5 kg Sb eq., and result in 3.12 kg C deficit from land use while consuming 24.58 MJ of energy per kg organic tomato. The impacts from earlier started tomato cultures are higher, as increased yield does not remedy increased energy use. The result from current production shows that direct energy consumption is responsible for the main impact on climate change (78%), cumulative energy demand (75%), marine eutrophication (56%) and land use (62%). However, expected future changes in the energy system towards 2030 are likely to reduce life cycle environmental impacts considerably (reduction potential for climate change impact: 69%, cumulative energy demand: 48%, eutrophication potential: 47%, mineral, fossil and renewable resource depletion: 4%, land use: 48%) as intensity of the energy supply changes. Mitigation options such as increased energy efficiency, alternative heat sources and agronomic management decisions are further discussed.

Sustainability assessment of peri-urban organic horticulture — A case study in the United Kingdom

PurposeThere is a growing concern about the resilience and sustainability of horticultural production in the United Kingdom (UK) as a result of high energy costs and insufficient local labour, causing over-reliance on imports. In this study, we present an integrated environmental and economic assessment of organic peri-urban horticulture using primary data from a farm in Sheffield.MethodsThis study includes a farm-to-gate hybrid life cycle assessment (LCA) using the ReCIPE (H) approach for the functional unit of 1-kg tomatoes produced in an unheated polytunnel without supplementary lighting, and 1 kg of field-grown courgettes. All analyses were conducted in SimaPro software using environmental data from the ecoinvent database. Results were compared with those from a systematic literature review of similar studies.ResultsWe found that the production of organic tomatoes and courgettes resulted in a global warming potential (GWP) of 0.61 kg CO2-eq and 0.11 kg CO2-eq respectively using a process-based LCA approach. Using a hybrid LCA approach, however, yielded a GWP of 3.53 kg CO2-eq and 1.70 kg CO2-eq for the production of organic tomatoes and courgettes respectively. An additional scenario included farmgate-to-warehouse transportation for both domestic and imported produce from Spain, but found that the GWP of tomatoes in the case study was 1.87 times higher than those from Spain. Economic analysis showed that the marginal increase in the prices of tomatoes and courgettes from the case study farm was 4.6 and 5.15 times less than the market prices.ConclusionWe conclude that the studied production system is both economically and environmentally sustainable as compared to the existing scenario. Other potential benefits of peri-urban organic horticulture include employment, mental health, community cohesion, which remain to be explored in a future qualitative study. The present study is novel as it appears to be the first application of hybrid LCA to UK horticulture. The findings are highly topical given the recent horticultural supply constraints in the UK.

Unveiling the Factors Influencing Organic Tomato (Solanum lycopersicum) Production: An Empirical Evidence from the Mymensingh District of Bangladesh

Tomato is one of the most popular and widely grown vegetables, and faces a demand-supply gap, prompting the need for enhanced production. As global agriculture shifts towards organic practices, this study was undertaken to explore the socioeconomic status of organic tomato producers, assess the factors impacting organic tomato production, and identify the production related constraints. Following the simple random sampling method, a total of 60 organic tomato producers were selected from two villages in Gouripur Upazila under the Mymensingh district and they were interviewed using a structured interview schedule. The research reveals that the majority of farmers were within the productive age range of 36-50 years, with male dominance in the field. Family sizes were diverse, with medium-sized families being the most prevalent. A substantial proportion of farmers possess secondary-level education. Experience in organic tomato farming ranges from 5 to over 15 years, indicating a diverse level of expertise. The Cobb-Douglas revenue type production function was used to determine the effect of selected inputs on organic tomato production. The findings of production function analysis revealed that costs related to human labor, seed, organic fertilizer, bio-pesticides, and land use positively impact organic tomato production. The study also identified major problems faced by farmers in organic tomato production in which high disease and pest attacks were the most significant problems in the study area. Therefore this study will be helpful for farmers to increase organic tomato production and relevant policymakers to support organic tomato producers and further promote sustainable agriculture in this region.

Tomato Plant Microbiota under Conventional and Organic Fertilization Regimes in a Soilless Culture System.

Tomato is the main vegetable cultivated under soilless culture systems (SCSs); production of organic tomato under SCSs has increased due to consumer demands for healthier and environmentally friendly vegetables. However, organic tomato production under SCSs has been associated with low crop performance and fruit quality defects. These agricultural deficiencies could be linked to alterations in tomato plant microbiota; nonetheless, this issue has not been sufficiently addressed. Thus, the main goal of the present study was to characterize the rhizosphere and phyllosphere of tomato plants cultivated under conventional and organic SCSs. To accomplish this goal, tomato plants grown in commercial greenhouses under conventional or organic SCSs were tested at 8, 26, and 44 weeks after seedling transplantation. Substrate (n = 24), root (n = 24), and fruit (n = 24) composite samples were subjected to DNA extraction and high-throughput 16S rRNA gene sequencing. The present study revealed that the tomato core microbiota was predominantly constituted by Proteobacteria, Actinobacteria, and Firmicutes. Remarkably, six bacterial families, Bacillaceae, Microbacteriaceae, Nocardioidaceae, Pseudomonadaceae, Rhodobacteraceae, and Sphingomonadaceae, were shared among all substrate, rhizosphere, and fruit samples. Importantly, it was shown that plants under organic SCSs undergo a dysbiosis characterized by significant changes in the relative abundance of Bradyrhizobiaceae, Caulobacteraceae, Chitinophagaceae, Enterobacteriaceae, Erythrobacteraceae, Flavobacteriaceae, Nocardioidaceae, Rhodobacteraceae, and Streptomycetaceae. These results suggest that microbial alterations in substrates, roots, and fruits could be potential factors in contributing to the crop performance and fruit quality deficiencies observed in organic SCSs.

Grafting and Plant Density Influence Tomato Production in Organic Farming System

The tomato is a key crop cultivated worldwide for the fresh and processing markets. Only a small percentage of the tomatoes processed by industries were produced following the guidelines of the organic farming system. Potential reasons for the limited share of organic tomato production are probably related to the lower yield obtained in organic farming in comparison with conventional farming. In this study, the use of the cherry tomato genotype ‘Tomito’ as a rootstock and two different plant densities (2.5 and 1.25 plant m−2) were evaluated in order to improve the agronomic performances of the commercial processing tomato genotype ‘H3402′ cultivated in the organic farming system. Agronomic and quality parameters were assessed at harvest time. The plant density influenced the plant biometric parameters, mass and marketable yield, and fruit health and quality. The use of a rootstock improved the marketable yield per plant (more than 59%), with the quality of the fruit decreasing the number of sunburnt fruits (−27.7%). The use of the ‘Tomito’ as a rootstock and a plant density of 2.5 plant m−2 are the better choices to achieve good performances in optimal environmental conditions. However, further studies are required to validate these results both in other environments and using different scions.

Agronomic Performance and Nutraceutical Quality of a Tomato Germplasm Line Selected under Organic Production System

Organic tomato production is increasing worldwide, thus making necessary the development of varieties adapted to this farming system. It is now well known that the implementation of local tomato plant breeding programs for organic farming is required to increase the performance of varieties in this typology of cultivation regime. In this research, the agronomic performance, nutraceutical contents, and radical scavenging activity of a tomato germplasm line (OSTGL), selected under organically grown conditions, were evaluated for two consecutive years (2018 and 2019) in comparison with the variety ‘Rio Grande’, frequently grown organically in Tunisia. Carotenoids, phenolics, vitamin C, and radical scavenging capacity were assayed spectrophotometrically, while tocopherols were analyzed by HPLC. All data were not affected by year-to-year variability. The OSTGL line showed significantly higher marketable yield, total phenol, flavonoid, vitamin C, α-tocopherol and γ-tocopherol contents, along with radical scavenging activity. The OSTGL red-ripe berries also showed comparable values for average weight, soluble solids, pH, titratable acidity, firmness and coloration, as well as lycopene and β-carotene contents. This open pollinated tomato germplasm line demonstrated to be an effective sustainable variety for improving fruit yield, agronomic, and nutraceutical characteristics under an organic management system.

Farmer’s Adoption and Effectiveness of Insect Pests Management Strategies in Organic Tomato Fields

A study was conducted in organic and intensive tomato growing areas located in Manikganj and Narsingdi districts of Dhaka division. A total of 30 organic tomato growers were selected from 5 randomly selected villages of Manikganj and Narsingdi. Data were collected from September 2020 to September 2021. Most frequently used insect pest management strategies by the organic farmers under the study areas were; T0=Untreated control (Used resistant varieties only), T1=Pheromone trap (Plastic pot), T2=Sticky trap+ Neem leaf powder @ 1kg/10L of water at 7 days interval, T3=Bait trap+ Neem leaf powder @ 1kg/10L of water at 7 days interval, T4=Light trap+ Mahogany seed powder @ 20gm/L of water at 7 days interval and T5= Pheromone trap + Trichogramma evanescens (100 points ha-1 at 500 wasps per point). For the untreated control of tomato fruit borer, T1=Pheromone trap (Plastic pot) was the most frequently used (52.67%) in the study area whereas T5= Pheromone trap + Trichogramma evanescens (16.67%) was used by the least number of organic farmers besides untreated control T0 (8.67%). The highest benefit cost ratio was 1.51 recorded from the treatment T5= Pheromone trap + Trichogramma evanescens, lowest benefit cost ratio was 1.30 recorded for tomato production from the untreated control treatment T0. Due to reduced operating costs, the benefit-cost ratio for producing organic tomato was comparable to and close to that of growing high yielding tomato using inorganic methods. The difference between the BCR of organic tomato production procedures and inorganic tomato production practices was eventually eliminated by high market price and rising demand of organic produces.

Evaluation of Copper-Free Alternatives to Control Grey Mould in Organic Mediterranean Greenhouse Tomato Production

Grey mould caused by Botrytis cinerea is an endemic disease in greenhouse tomato crops in the Mediterranean Basin, where the scarcity of heating systems together with the winter weather conditions makes the use of fungicides necessary. The availability of fungicides for organic tomato production is limited, and traditionally, farmers have used copper-based formulations. In the present work, in vitro tests with twelve commercial formulations resulted in cinnamon extract and potassium hydrogen carbonate (PHC) showing high efficacy in the inhibition of B. cinerea growth. Both formulations were evaluated in on-farm greenhouse trials conducted for two seasons (2019/2020 and 2020/2021) in three greenhouses located in Almería, Spain. In terms of controlling Botrytis, PHC showed efficacy results comparable to or even better than those that have been obtained for copper oxychloride. Weather conditions outside and inside the greenhouse were conducive to the onset and development of the disease. Tomato variety selection and pruning practices (flush cuttings) were the main factors that reduced the use of copper-based formulations or any other fungicide to prevent grey mould infection. Smart and integrated management of the mentioned factors could lead to the substitution of copper to control Botrytis in the crop system studied here.

Weed Management by In Situ Cover Crops and Anaerobic Soil Disinfestation in Plasticulture

Weeds negatively affect organic vegetable crop growth and profitability. Weed management is the greatest challenge for vegetable organic growers since control options are limited for organic vegetable production. Anaerobic soil disinfestation (ASD) is a novel non-chemical pest management technique that creates anoxic conditions in the topsoil layer for a limited time. ASD is primarily based on the addition of labile carbon sources to topsoil to promote anaerobic conditions driven by microorganisms in moist soil mulched with polyethylene film (polyfim). Field studies were conducted in the summer–fall of 2020 and 2021 to determine the efficacy of warm season cover crops used as carbon sources for ASD and their role in weed management. The study used a factorial experimental design with four cover crop residue treatments (sorghum-sudangrass, sunn hemp, both, or none) in two soil aeration conditions (aerated or non-aerated). Cover crops were grown for 75 days, incorporated into the soil, and sealed with totally impermeable film (TIF) clear mulch, followed by a 4-week ASD process. All incorporated cover crop treatments in non-aerated conditions generated moderate to higher anaerobic conditions (0–150 mV) and provided significantly higher (p < 0.05) weed control than all the other treatments tested or controls. Tomato plants transplanted in non-aerated, cover crops incorporated plots were more vigorous and produced higher yields than aerated plots. No phytotoxicity was observed on tomato plants following ASD treatment in any of the treatments tested. This study demonstrated that warm season cover crops could potentially serve as a carbon source for ASD in organic tomato production.

Economic Analysis of Grafted Organic Tomato Production in High Tunnels

With the phase-out of methyl bromide because of its impact on ozone depletion and the shift to a more protected culture system in organic vegetable production, grafting practice has gained greater attention in the United States because it may be considered a viable disease control method in organic vegetable production. However, there is a lack of information on the economic feasibility of using grafting in organic tomato (Solanum lycopersicum) production in a protected culture system such as a high-tunnel system. Using 2-year on-station trial data collected in Citra, FL, we examined the effect of using grafting on the economic returns of organic tomato production in high tunnels. Our analysis suggests that grafting tends to increase the marketable yield of organic tomato production in high tunnels. However, the enhanced yield does not necessarily increase the net return, depending on market conditions and the relative performance of grafted transplants. In addition, our results indicate that the net return of grafted production is highly sensitive to the tomato selling price. Obtaining a price premium is essential for increasing the profitability of grafted organic tomato production in high tunnels.

Exploring grower strategies and needs for enhancing organic disease management of tomato late blight

AbstractLate blight, caused by the oomycete Phytophthora infestans, poses a significant challenge to organic tomato and potato production systems across the globe. To enhance education and outreach programming pertaining to tomato organic late blight management in Wisconsin, we sought to identify grower strategies and needs through an online survey conducted during spring 2018. Our findings demonstrated that organic growers emphasized crop diversity, crop rotation and soil health in their late blight management decisions. Grower concerns about biopesticides were identified and suggest that the use of input-based products within integrated management programs could be enhanced by further research on effectiveness and modes of actions. Additionally, stronger emphasis on oomycete pathogen biology and the significance of late blight as a community disease were identified as important areas of emphasis in the development of organic disease management education programming and resources that promote more effective cultural and chemical disease management strategies that adhere to the regulation and principles underlying the USDA National Organic Program. The integration of a live polling questionnaire conducted in winter 2019 allowed us to corroborate findings from the online survey and underscored the importance of two-way learning to enhance outreach efforts between Extension and organic growers in Wisconsin and the surrounding upper Midwestern states.

Effects of Faba Bean Strip Cropping in an Outdoor Organic Tomato System on Soil Nutrient Availability, Production, and N Budget under Different Fertilizations

Crop diversification has been identified as a tool to improve both productive and environmental performances of organic horticulture. We tested the introduction of faba beans in a tomato cropping system—both as preceding crop and in strip cropping (SC)—under different fertilization strategies—faba residues, animal manure, and vegetable compost. We studied: (i) the tomato nutrient uptake and yield and quality; (ii) the soil-N and P, the N-budget, and the mycorrhizal colonization. SC did not provide consistent positive effects on tomato production and quality, namely the N-uptake, N in the tomato yield, the mean fruit weight, and the sugar accumulation in berries, regardless of the type of fertilizers applied. SC improved the tomato dry yield and P-uptake, especially in years when the faba growth and the subsequent yield were problematic. Faba residues could provide sufficient N to sustain tomato production but care should be given in balancing additional N-inputs. Organic fertilization increased the soil-N concentration but did not always translate into an increased yield and a higher quality production, with the risk of escalating N-losses. SC improved the soil-P availability and mycorrhizal colonization in tomato, due to the rhizobia–mycorrhiza-mycorrhiza association, especially when coupled with organic fertilization. Finally, introducing faba as SC holds potential to improve the productive and environmental performance of organic tomato production.