Greenhouse Cucumber Production Research Articles

CPSM: A Dynamic Simulation Model for Cucumber Productivity in Solar Greenhouse Based on the Principle of Effective Accumulated Temperature

The Cucumber Productivity Simulation Model (CPSM) was developed to precisely predict the dynamic process of cucumber productivity in a solar greenhouse. This research conducted a variety of sowing experiments and collected data on cucumber productivity and meteorological conditions from 2013 to 2015 and 2018 to 2020. Employing the principles of least squares, the relationship between cucumber productivity indicators and effective accumulated temperature (EAT) was fitted, determining key crop parameters and constructing the CPSM. Validation of the model was conducted using independent experimental data, evaluating its simulation accuracy. The results indicate that (1) CPSM can dynamically and meticulously simulate the formation process of different productivity indicators in cucumber. Normalized root mean square errors (NRMSE) ranged from 0.44% to 19.64%, and mean relative errors (MRE) ranged from 0.31% to 17.23% across different productivity indicator models. The models for organ water content, maximum root length, specific leaf area, and organ fresh weight distribution index demonstrated high simulation accuracy, while others showed relatively high accuracy. (2) Simulation accuracy varied with indicators and varieties. 19 indicators (34.55%) exhibited high simulation accuracy and 30 indicators (54.55%) showed relatively high accuracy. The JY35 variety (10.44 ± 8.49%) outperformed the JS206 variety (13.44 ± 8.50%) in terms of simulation accuracy. The JY35 variety had 39 superior productivity indicators (70.91%) while the JS206 variety had sixteen (29.09%). CPSM utilizes easily accessible temperature data as its input, allowing for precise and detailed simulation of productivity indicators for cucumber production in solar greenhouses. This research lays a theoretical foundation and provides technical support for guiding intelligent production management, efficient utilization of agricultural resources, and climate change productivity assessment in solar greenhouse cucumber production.

Optimization of Low-Tech Protected Structure and Irrigation Regime for Cucumber Production under Hot Arid Regions of India.

Water scarcity and climate variability impede the realization of satisfactory vegetable yields in arid regions. It is imperative to delve into high-productivity and water-use-efficient protected cultivation systems for the sustained supply of vegetables in harsh arid climates. A strenuous effort was made to find suitable protected structures and levels of irrigation for greenhouse cucumber production in hot arid zones of India. In this endeavor, the effects of three low-tech passively ventilated protected structures, i.e., naturally ventilated polyhouse (NVP), insect-proof screenhouse (IPS) and shade screenhouse (SHS), as well as three levels of irrigation (100%, 80% and 60% of evapotranspiration, ET) were assessed for different morpho-physiological, yield and quality traits of the cucumber in a two-year study. Among the low-tech protected structures, NVP was found superior to IPS and SHS for cucumber performance, as evidenced by distinctly higher fruit yields (i.e., 31% and 121%, respectively) arising as a result of higher fruit number/plants and mean fruit weights under NVP. The fruit yield decreased in response to the degree of water shortage in deficit irrigation across all protected structures. However, the interaction effect of the protected structure and irrigation regime reveals that plants grown under moderate deficit (MD, 20% deficit) inside NVP could provide higher yields than those obtained under well-watered (WW, 100% of ET) conditions inside IPS or SHS. Plant growth indices such as vine length, node number/plant, and shoot dry mass were also measured higher under NVP. The greater performance of cucumber under NVP was attributed to a better plant physiological status (i.e., higher photosystem II efficiency, leaf relative water content and lower leaf water potential). The water deficit increased water productivity progressively with its severity; it remained higher in NVP, as reflected by 20% and 94% higher water productivity than those recorded in IPS and SHS, respectively, across different irrigation levels. With the exception of total soluble solids and fruit dry matter content (which were recorded higher), fruit quality parameters were reduced under water deficit conditions. The findings of this study emphasize the importance of considering suitable low-tech protected structures (i.e., NVP) and irrigation levels (i.e., normal rates for higher yields and moderate deficit (-20%) for satisfactory yields) for cucumber in hot arid regions. The results provide valuable insights for growers as well as researchers aiming to increase vegetable production under harsh climates and the water-limiting conditions of arid regions.

Sustainability Assessment of Greenhouse Cucumber and Tomato Production Agroecosystems Based on Emergy and Economic Analysis in Sistan Region

Sustainability Assessment of Greenhouse Cucumber and Tomato Production Agroecosystems Based on Emergy and Economic Analysis in Sistan Region

Energy Analysis for Two Production Systems of Cucumber

This research, conducted in Gotvand, southwest of Iran, compared the energy consumption of two cucumber production systems: field and greenhouse production systems. In this study, energy inputs of two production systems of cucumber (including seed, pesticide, human labor, machinery, diesel fuel, electricity, organic manure, chemical fertilizer) were determined from questionnaires completed by farmers. The results of the experiment indicated that the energy input of the two cultivation systems was not significantly different in input energies. In both cucumber production systems, the most input energy was allocated to nitrogen fertilizer (57% and 53% for field and greenhouse, respectively) followed by diesel fuel (21% in both production systems). Non-renewable energies accounted for 90 and 88% of the total energy input to the farm and greenhouse systems, respectively. Total output energy of field and greenhouse cucumber production system was 33000 and 34000 MJ, respectively. Reducing the consumption of nitrogen fertilizer through the use of appropriate crop rotation is a suitable solution to improve energy efficiency in the cucumber production system.

Evolution of Benzimidazole Resistance Caused by Multiple Double Mutations of β-Tubulin in Corynespora cassiicola.

Cucumber target leaf spot caused by Corynespora cassiicola has devastated greenhouse cucumber production. In our previous study, the resistance monitoring of C. cassiicola to carbendazim was carried out, and a large number of resistant populations carrying various mutations (M163I&E198A, F167Y&E198A, F200S&E198A, or E198A) in β-tubulin were detected. However, the single-point mutations M163I, F167Y, and F200S have remained undetected. To investigate the evolutionary mechanism of double mutations in β-tubulin of C. cassiicola resistance to benzimidazoles, site-directed mutagenesis was used to construct alleles with corresponding mutation genotypes in β-tubulin. Through PEG-mediated protoplast transformation, all the mutants except for the M163I mutation were obtained and conferred resistance to benzimidazoles. It was found that the mutants conferring the E198A or double-point mutations showed high resistance to carbendazim and benomyl, but the mutants conferring the F167Y or F200S mutations showed moderate resistance. Except, the F200S mutants showed low resistance, the resistance level of the other mutants to thiabendazole seemed no difference. In addition, compared to the other mutants, the F167Y and F200S mutants suffered a more severe fitness penalty in mycelial growth, sporulation, and virulence. Thus, combined with the resistance level, fitness, and molecular docking results, we concluded that the field double mutations (F167Y&E198A and F200S&E198A) evolved from the single mutations F167Y and F200S, respectively.

Comparison of rockwool and coir for greenhouse cucumber production: chemical element, plant growth, and fruit quality

Replacing rockwool with more sustainable materials, such as coir, is an effective measure to improve the sustainability of soilless cultivation in the greenhouse. To comprehensively assess the feasibility of coir before using it widely, coir was compared to rockwool as a cucumber cultivation substrate to evaluate its performance on mineral elements in the substrates, drainage, and in the plants. Plant growth, amino acids, and flavor substances of cucumber fruits were also compared between the two substrates. Compared to rockwool, coir significantly increased the LAI and yield of cucumber crops as well as contents of Ca, Mg, S, Cl and Zn in leaves and fruits. Contents of P, K, Ca, Mg, Cl, Zn, and B in the substrate were higher for coir while those of Fe, Cu, and Mn in the drainage lower. Moreover, coir also significantly increased contents of amino acids (His, Leu, Ile, Phe, Lys, Asp, Glu and Pro) and flavor substance (TC, PS, TP, CLL, CuB, and LA) in cucumber fruits. Our results demonstrated the potential of coir as a replacement of rockwool to improve sustainability of soilless cultivation in the greenhouse.

The Effect of LED and HPS Assimilation Lighting on Leaf Anatomy, Chlorophyll and Carotenoid Autofluorescence Signals, and Some Physiological and Chemical Leaf Traits Related to the Productivity of Cucumber (Cucumis sativus L.) in High-Wire Cultivation

Supplemental lighting with light-emitting diode (LED) lamps and/or high-pressure sodium (HPS) lamps was applied to increase the activity of the photosynthetic apparatus and thus productivity of greenhouse cucumber (Cucumis sativus L.) in a high-wire growing system. The colocalisation of the chlorophyll of PSII (located mainly in grana) and carotenoid fluorescence signals in chloroplasts of cucumber leaves was studied under confocal microscopy. Leaf anatomy and some chemical quality traits (dry matter, chlorophyll, carotenoids, total soluble solids, total sugars and nitrate reductase activity) as well as selected chlorophyll fluorescence parameters were also investigated and subjected to the multidimensional principal component analysis together with the data on fruit yield. Under LED lighting, a lower correlation between the occurrence of chlorophyll and carotenoid fluorescence signals was observed, especially in older (lower-located) leaves, which may have resulted from changes in the distribution of carotenoids within chloroplasts and/or relative concentrations of chlorophyll and carotenoids. Compared to toplighting with HPS lamps, most commonly used in commercial greenhouse cucumber production, the application of LED interlighting, especially in combination with LED toplighting, led to the increase in chlorophyll and carotenoid content and photosynthetic performance index in older leaves, which was related to the increased cucumber productivity.

Influence of Biochar, Rock Phosphate, and Urea Nitrogen Fertilizer on Growth and Yield of Cucumber (Cucumis sativus) Grown in Standoff, Southern Alberta Greenhouse

Two trials were performed in greenhouse Standoff, Southern Alberta to investigate urea, rock phosphate, and biochar soil amendment on cucumber crops. The objective of the study was to confirm the effectiveness of rock phosphate and biochar with urea on greenhouse cucumber production. Two experiments were conducted in the Summer of 2020 and 2021 cropping seasons. The treatments applied in 2020 were the varying application of rock phosphate at 0 for control, 50 kg P ha-1 and 100 kg P ha-1 for phosphorus, and urea at 60 kg N ha-1 and 90 kg N ha-1 for nitrogen with their combinations N60 + P50, N90 + P100. In the 2021 cropping season, treatments applied were varying levels of Biochar (C) applied at a rate of 25 kg ha-1 (LC), 50 kg ha-1 (MC), and 100 kg ha-1 HC for Low, Medium, and High level, respectively, Urea (N) was applied at 30 kg N ha-1 and 60 kg N ha-1 (Low N and High N level, respectively) while rock phosphate (P) was applied at 25 kg P ha-1 and 50 kg P ha-1 (Low P and High P level, respectively) with their combinations. The seven treatments for each cropping season were replicated three times resulting in twenty-one experimental pots. The agronomical parameters data collected were subjected to one-way univariate analysis of variance using Duncan’s Multiple Range Test at 5% to separate the treatment means. The results of the experiment showed that High P and Low N treated pots influenced the growth of cucumber crop at 122 days after sowing (DAS) while High N, Low N, and Low N + Low P jointly favored the highest number of cucumbers on the vines than other treated pots at 82 DAS during the 2020 cropping season. However, all the treatments supported cucumber vine length except control and High P at 96 DAS while Low P + MC, High P, and High N+ P produced more fruits than control, High N and Low N + P + HC treatments at 96 DAS during the 2021 cropping season. It was observed that the addition of biochar in the 2021 cropping season influenced the growth and yield of cucumber when compared performance of cucumber crops in two growing seasons. This experiment advocates the use of biochar soil amendment in cucumber production.

Energy-economic-environmental cycle evaluation comparing two polyethylene and polycarbonate plastic greenhouses in cucumber production (from production to packaging and distribution)

Excessive consumption and improper management of inputs would lead to environmental damages, as well as decreased economic benefits. Thus, a thorough examination of the entire production process from the viewpoint of energy flow, economic profit, and environmental effects can identify hotspots and facilitate input management. Accordingly, in the current investigation, energy, economic and environmental aspects of greenhouse cucumber production systems were measured by life cycle assessment (LCA) technique and cumulative exergy demand (CExD) analysis by considering different greenhouse structures. Furthermore, the data envelopment analysis (DEA) approach was used to determine the efficiency of manufacturing units and optimal consumption pattern. The information required was acquired through interviews and questionnaires with 35 greenhouse owners, and consultation with greenhouse enterprises in the Khuzestan province of Iran. Based on the findings, energy consumed was 6626.45 MJton−1 in Sc1, and 6410.32 MJton−1 in Sc 3. The findings of benchmarking revealed that boosting the efficiency of the crop production process can lower input energy by 14.80%. The energy consumption for the construction of the first and second type of greenhouses was calculated to be 14,811.13 and 17,541.73 MJ (1000 m2)−1, respectively. With regard to the production variable costs, chemical fertilizers and labor had the largest contributions to the total expenses, at 7.6 (15.41%) and 7.87 $tonne−1(15.94%), respectively. In the evaluation of the energy and economic indicators, the combined indicator of Energy Intensiveness for the first and second types of greenhouse systems was found to be 80.26 and 77.07 MJ$−1, respectively, indicating higher energy-economic productivity of the first type of system. Based on LCA results, direct emissions due to input consumption (air: carbon dioxide (CO2), and nitrogen oxides (NOx); soil: mercury (Hg), copper (Cu), and lead (Pb)), and indirect emissions induced by chemical fertilizers, greenhouse structures, and chemical pesticides production are the environmental hotspots.

Assessment of Non-Conventional Irrigation Water in Greenhouse Cucumber (Cucumis sativus) Production

Climate change, urbanization and subsequent environmental changes are depleting freshwater resources around the globe. The reuse of domestic, industrial and agricultural wastewater is an alternative approach to freshwater that can be used for irrigation purposes. However, these wastewaters may contain hazardous and toxic elements, such as heavy metals that are hazardous for human health and the environment. Therefore, an experiment was conducted to evaluate the concentration of macro, micro and heavy metals in cucumber irrigated with different resources (tap water, greywater, dairy water and wastewater). The results showed that the use of different irrigation resources has increased the level of macro (sodium (Na), potassium (K), calcium (Ca), magnesium (Mg)), microelements (zinc (Zn), iron (Fe), manganese (Mn)), and heavy metals (copper (Cu), barium (Ba), lead (Pb) and cadmium (Cd)) in cucumber leaves and fruits. However, their levels were in the range that is safe for human health and the environment was as recommended by FAO maximum values of trace elements (Zn, 2.0; Fe 1.0; Mn, 0.2; Cu, 0.2; Pb, 5.0, and Cd, 0.01 mgL−1). Based on observations, it was also revealed that among different irrigation resources, the use of dairy water in cucumber improved its agronomic attributes and maximum plant yield (1191.02 g), while the different irrigation resources showed a non-significant impact on fruit diameter. However, total soluble solid contents (TSS) were more significant in cucumber fruits treated with wastewater (2.26 °brix) followed by dairy water (2.06 °brix), while the least TSS contents (1.57 °brix) were observed in cucumber plants treated with tap water. The significance of non-conventional irrigation water use in agriculture, particularly greenhouse cucumber (Cucumis sativus) production, is discussed.

Reducing the environmental risks related to phosphorus surplus resulting from greenhouse cucumber production in China

Excessive phosphorus (P) inputs from manure and synthetic fertilizers leads to high environmental risk in greenhouse vegetable production systems. In the current study, we determined whether a system of P fertilization that attempts to achieve a zero-P surplus balances agronomic, economic, and environmental concerns. A field experiment was conducted to evaluate the potential of integrated inorganic and organic nutrient management to provide both high yield and minimal environmental risk in a typical region of greenhouse vegetable production in China. Three treatments were compared: farmers’ practice (FP), current recommended nutrient management (CRNM), and designed balanced nutrient management (DBNM, with P input optimized based on crop demand). The results indicated that in the greenhouse cucumber production system, the seasonal P surplus of FP was as high as 410 kg P ha−1; this increased the movement of P to the subsoil, causing a high risk of P loss, i.e., a P index >9, and a high eutrophication potential (87.4 kg PO4-eq ha−1). Compared with FP, CRNM (which had a 76% lower P fertilizer input) significantly reduced the P surplus, the risk of P loss, and the eutrophication potential, and increased yield incomes and net ecosystem economic benefits by 18.0% and 31.8%, respectively. Compared with CRNM, DBNM significantly reduced the P surplus by 84.5% and the environmental damage cost by 19.0%, while increased the input cost by 23.0%. Therefore, the DBNM strategy is recommended in greenhouse vegetable production to reduce the P surplus and environmental costs, and to obtain high yield and economic benefits.

Efficacy of Phytoseiulus persimilis and Amblyseius swirskii for integrated pest management for greenhouse cucumbers under Mediterranean environmental conditions

AbstractThe greenhouse cucumber pests, Bemisia tabaci (Hemiptera: Aleyrodidae), Frankliniella occidentalis (Thysanoptera: Thripidae), and Tetranychus urticae (Acari: Tetranychidae), are major threats to the production of greenhouse cucumbers (Cucurbitaceae) in Lebanon. The development of insecticide resistance by these pests has prompted the use of alternative and sustainable pest management strategies. In this study, we used integrated pest management strategies, including the release of the biological control agents, Amblyseius swirskii Athias-Henriot (Mesostigmata: Phytoseiidae) and Phytoseiulus persimilis Athias-Henriot (Mesostigmata: Phytoseiidae), to control whitefly, thrips, and two-spotted spider mite populations on greenhouse cucumber plants in two commercial production sites (sites A and B). We also compared the efficacy of pest population suppression using the integrated pest management strategy with that of chemical pest control. Our results show that biological control effectively maintains the cucumber pest populations below the economic threshold when coupled with additional integrated pest management measures. In addition, we show that biological control agents were equally or more effective in pest population suppression compared to eight and 12 insecticidal and acaricidal sprays performed in the control greenhouses at sites A and B, respectively. Altogether, our results show the efficacy of adopting integrated pest management and biological control for pest population suppression in greenhouse cucumber production under Mediterranean environmental conditions.

Dynamics of chitosan based NPK-nanofertilizers in greenhouse cucumber production system

Aim: To study the effect of NPK-nonofertilizers on growth, reproductive and yield parameters as well as nutrient recovery efficiency in greenhouse cucumber. Methodology: The performance of greenhouse cucumber cultivar KPCH-1 was studied using six treatments namely 100% RDF(90:75:75 kg ha-1) through water soluble fertilizer (WSF), 60% RDF as nanofertilizer, 50% RDF as nanofertilizer, 40% RDF as nanofertilizer, 30% RDF as nanofertilizer and absolute control. Growth, reproductive and yield parameters of greenhouse cucumber as well as nutrient use efficiency were assessed during cropping period. Results: The plants administered with 60% RDF through nano-fertilizer showed12.07%, 11.85% and 15.72% higher increase in leaf area at 30 and 60 DAS as well as at final harvest, respectively, over 100% RDF through WSF. The greenhouse cucumber fertigated with 40% RDF as nanofertilizer recorded maximum number of pickings and number of fruits per vine accounting for maximum increase in marketable yield compared to WSF. The cucumber plants administered with 40% RDF as nano-fertilizers also recorded maximum apparent N, P and K recovery efficiency. Interpretation: Nano-fertilizers have ability of controlled release of desired nutrients at their site of action. Despite of lower concentration, higher yield obtained at 40% nano-NPK fertilizer was associated with high nutrient recovery by nanofertilizers. Key words: Chitosan, Greenhouse cucumber, Nano-fertilizers, Horticultural traits

Preliminary Study on the Control of Cucumber Green Mottle Mosaic Virus in Commercial Greenhouses Using Agricultural Disinfectants and Resistant Cucumber Varieties

Cucumber green mottle mosaic virus (CGMMV) is a re-emerging threat to greenhouse cucumber and other Cucurbitaceae crop production worldwide. This seed-borne virus can easily spread from a contaminated seeds to seedlings and to adjacent plants through mechanical contact of the foliage of diseased and healthy plants causing extensive yield losses. Additionally, infection may not be limited to the current crop but may also affect subsequent crops due to the long-term persistence of the virus on contaminated crop residues, greenhouse hard surfaces and soil or soil-less greenhouse substrates. In the present work, three greenhouse experiments were conducted to develop an integrated pest management strategy towards controlling CGMMV in commercial cucumber greenhouses, by implementing an effective sanitization program and using resistant and grafted cucumber varieties. Results of sanitization highlighted that pressure washing and cleansing with an alkaline foam cleanser eliminated CGMMV on some of the most heavily infested areas. However, three successive applications of cleanser and disinfectants were essential to completely eliminate CGMMV on porous and uneven surfaces, such as cement alleyway, tray gutters and floor mats. The screening of 15 cucumber varieties revealed that one Mini (‘Khassib’) and three Long English (‘Sepire’, ‘Bomber’ and ‘LC13900′) had reduced or delayed CGMMV infection spread in the greenhouse but were intermediate in yield. The most resistant Mini variety was ‘Katrina’. This variety showed low CGMMV infection level and high fruit yield. The varieties ‘Jawell’, ‘RZ 22-551′, ‘Sunniwell’, ‘Bonbon’ and ‘Dee Lite’ were the most tolerant to CGMMV. They showed a high CGMMV infection level without compromising yield. These results proved the need for new productive cucumber varieties with CGMMV resistance. Grafting experiments showed a yield increase only in the case of grafted ‘Picowell’ over ‘Bonbon’ but no CGMMV resistance, which is a much more desirable result of grafting experiments in order to have economic potential. In all, the current study revealed unique methods of CGMMV management in commercial greenhouses that are recommended to growers for reducing crop losses and improving economic returns.

Remote control of greenhouse cucumber production with artificial intelligence – results from the first international autonomous greenhouse challenge

The world population is increasing rapidly together with the demand for healthy fresh food. Greenhouse industry can play an important role, but encounters difficulties finding skilled staff to manage crop production. Artificial intelligence (AI) reaches breakthroughs in several areas, however, not yet in horticulture. An international competition on “autonomous greenhouses” aims in combining horticultural expertise with AI to make breakthroughs in fresh food production with fewer resources. Five international teams with different background in horticulture and AI participated in a growing experiment. Each team had a 96-m2 modern greenhouse compartment at WUR to grow remotely a cucumber crop ('Hi-Power') during a 4-months period. Each compartment was equipped with standard actuators and sensors, heating, ventilation, screening, artificial lighting, fogging, CO2 supply and irrigation. Climate control set points were remotely determined by teams using own AI algorithms, actuators were operated by a climate and irrigation process computer. Additionally, teams sent instructions for the crop pruning strategy. Measurements and set points were exchanged via a digital interface. Achievements in AI-controlled compartments were compared with a reference compartment, operated manually by three commercial growers. Teams used additional individually chosen sensors such as RGB or thermal cameras, temperature-humidity-light-sensor-networks, root-zone sensors, sap-flow meters or crop-weighing sensors. Teams' strategies for remote control ranged from supervised, unsupervised and reinforcement machine learning. Teams were judged and received points on several aspects: 50% for net profit, 20% for sustainability indicators, energy- and water-use-efficiency and CO2 consumption, 30% for their artificial intelligence algorithms, novelty, level of autonomous control, robustness and scalability. The results obtained by different teams in terms of climate and growing strategies, different resource use efficiency and net profit are presented in this paper. One of the AI-controlled compartments achieved overall better results than the manual grown reference compartment.

Impact of energy flow optimization on the mitigation of environmental consequences and costs in greenhouse cucumber production

Cucumber, as a major cultivated plant in Iran, takes up more than 80% of greenhouse production. So, improving the production efficiency can save energy, reduce the environmental consequences and production costs, and also create a lot of job opportunities. The present study aimed to investigate the impact of energy flow optimization on the environmental impacts and costs in greenhouse cucumber production by data envelopment analysis (DEA) and life cycle assessment (LCA) methods. For environmental assessment, human health damage, ecosystem damage, and resource scarcity were considered and analyzed in the form of 8, 12, and 2 impact categories, respectively, using the ReCiPe2016 (H) method on endpoint level. Required data were collected through questionnaire from 30 cucumber growers. The results of the current status of environmental impacts showed the major contribution of fuels (natural gas and diesel) in all three main impact categories. Based on DEA analysis, 19 greenhouses (63%) were identified as inefficient units with a mean efficiency score of 0.70 (TE = 0.7). The highest inefficiency was related to the manure (72%), electricity (71.7%), and fuel (59%), respectively. Electricity and manure showed the highest saving potential, while the highest contribution to total energy saving was related to fuel (87%). Environmental analysis of optimized greenhouses showed that efficient use of inputs can reduce all environmental impacts between 7 and 80%, which highlights the importance of efficient resource management in this study. Also, production costs were decreased by about 67 $ tonne-1 (196 to 129 $) after the optimization of the units.

Remote control of greenhouse cucumber production with artificial intelligence – results from the first international autonomous challenge

The world population is increasing rapidly together with the demand for healthy fresh food. Greenhouse industry can play an important role, but encounters difficulties finding skilled staff to manage crop production. Artificial intelligence (AI) reaches breakthroughs in several areas, however, not yet in horticulture. An international competition on “autonomous greenhouses” aims in combining horticultural expertise with AI to make breakthroughs in fresh food production with fewer resources. Five international teams with different background in horticulture and AI participated in a growing experiment. Each team had a 96-m2 modern greenhouse compartment at WUR to grow remotely a cucumber crop ('Hi-Power') during a 4-months period. Each compartment was equipped with standard actuators and sensors, heating, ventilation, screening, artificial lighting, fogging, CO2 supply and irrigation. Climate control set points were remotely determined by teams using own AI algorithms, actuators were operated by a climate and irrigation process computer. Additionally, teams sent instructions for the crop pruning strategy. Measurements and set points were exchanged via a digital interface. Achievements in AI-controlled compartments were compared with a reference compartment, operated manually by three commercial growers. Teams used additional individually chosen sensors such as RGB or thermal cameras, temperature-humidity-light-sensor-networks, root-zone sensors, sap-flow meters or crop-weighing sensors. Teams' strategies for remote control ranged from supervised, unsupervised and reinforcement machine learning. Teams were judged and received points on several aspects: 50% for net profit, 20% for sustainability indicators, energy- and water-use-efficiency and CO2 consumption, 30% for their artificial intelligence algorithms, novelty, level of autonomous control, robustness and scalability. The results obtained by different teams in terms of climate and growing strategies, different resource use efficiency and net profit are presented in this paper. One of the AI-controlled compartments achieved overall better results than the manual grown reference compartment.

Comparison of Selected Costs in Greenhouse Cucumber Production with LED and HPS Supplemental Assimilation Lighting

The amount of energy used in agricultural production, processing and distribution is constantly increasing. During the winter months in the greenhouse production industry, the supplemental lighting required to keep up production levels results in high expenditure. Current technology uses broadband high-pressure sodium (HPS) lamps, which is not the most efficient light source for crop production. Recent breakthroughs in the development of light source technologies have led to new opportunities for the use of sustainable and highly efficient light sources in the form of LEDs (light-emitting diodes) for greenhouse lighting. The aim of the study was to evaluate the efficiency of using photosynthetically active radiation (PAR) light for cucumber yielding, production processes and its influence on the variable costs in the cultivation of cucumbers using three different types of lighting. The research was carried out using three individual greenhouse growing area compartments, whereby the plants contained within were lit using three combinations: 1. HPS standard illumination from top HPS sodium lamps—control, 2. HPS-LED—HPS toplighting and LED interlighting, and 3. LED-LED—100% LED lighting, both toplighting and interlighting with LED. The research was conducted in two independent winter crop cycles. The results of the research conducted indicate that the efficiency of light use was the highest in the LED-LED combination and the lowest in HPS, and the use of supplemental lamp lighting in the LED-LED combination (interlighting and toplighting) gives the most favorable surplus of all the variable costs over the value of production to be obtained. Despite the highest absolute level of variable costs in this type of supplemental lighting, the production value was higher by as much as 32.55% in relation to the HPS combination, which also translated into a gross margin that was higher by about ¾. However, it is worth pointing out that, in the HPS-LED combination, the share of lighting and heating costs in the total value of production was the lowest. It is also a combination currently recommended in the literature as being the most beneficial in greenhouse production.

Life cycle assessment of cucumber irrigation: unplanned water reuse versus groundwater resources in Tipaza (Algeria)

Abstract Effective quantitative and qualitative management of water for irrigation is crucial in many regions and the use of reclaimed water is a possible solution. Quantifying the impact of the use of such water is thus important. Using life cycle assessment methodology, this study analyzes the impact of water reuse irrigation and farmers’ practices in greenhouse cucumber production. Three scenarios concerned sources of water for irrigation and agricultural practices: the first scenario used surface water including reclaimed water, the second used groundwater. The third scenario resembled the first but also accounted for fertilizer application based on theoretical cucumber requirements. The third scenario showed 35% less fertilizer is required than the quantities farmers actually use. Our results show that the higher environmental impact of irrigation using reclaimed water than using groundwater is mainly due to over-fertilization. Comparison of the first and third scenarios also showed that the reduction in the environmental impact under the third scenario was significant. We conclude that LCA is a useful tool to compare the impacts of different water sources and farmers’ irrigation/fertilization management practices, and in particular, that the quantity of nutrients in reclaimed water should be deducted from the actual amount applied by the farmers.

Factors Affecting on Energy Efficiency of Greenhouse Cucumber Production in Central Region of Isfahan Province, Iran

Factors Affecting on Energy Efficiency of Greenhouse Cucumber Production in Central Region of Isfahan Province, Iran