[
  {
    "effect_size": 21.98,
    "effect_unit": "%",
    "ci_lower": 16.6,
    "ci_upper": 27.36,
    "conditions": "Meta-analysis of 73 cucumber studies. eCO2 also increased net photosynthesis +56.31% (95% CI 50.31–62.32), WUE +121.11%, and biomass +27.75%. Synergy with high light, suitable temperature, humidity, and fertilizer.",
    "study_count": 73,
    "comparison_count": null,
    "source_url": "https://doi.org/10.3389/fpls.2026.1826536",
    "potential_yield_effect": 21.98,
    "geography": "Global cucumber experiments",
    "intervention": "Elevated CO2, typically 800–1200 ppm",
    "comparator": "Ambient CO2",
    "dose": "",
    "dose_unit": "",
    "limitations": "Includes growth-chamber and greenhouse work. Venting, light, and N supply strongly moderate the yield response.",
    "source_year": 2026,
    "doi": "10.3389/fpls.2026.1826536",
    "baseline": "",
    "factor_id": "cucumber-co2-meta",
    "crop_id": "cucumber",
    "factor": "Elevated CO2 enrichment (800–1200 ppm optimum)",
    "factor_category": "CO2 / carbon availability",
    "direction": "positive",
    "effect_type": "yield_gain",
    "evidence_type": "meta_analysis",
    "evidence_strength": "High",
    "prairie_relevance": "high",
    "source_title": "Optimizing carbon dioxide enrichment with environmental management to improve photosynthesis, water use efficiency and yield in cucumbers: a meta-analysis study (2026)",
    "notes": "Cucumber-specific yield mean is lower than the all-vegetable fresh-yield mean of +32.9% (Dong et al. 2020). Closed Alberta winter houses are the practical window for enrichment."
  },
  {
    "effect_size": 35.0,
    "effect_unit": "%",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "43-day plastic-greenhouse trial. SL+CO2 increased yield 35% versus unlit ambient-CO2 control. Economic analysis: income rate 106% (SL) and 111% (SL+CO2) of control.",
    "study_count": 1,
    "comparison_count": null,
    "source_url": "https://doi.org/10.1007/s13580-024-00638-y",
    "potential_yield_effect": 35.0,
    "geography": "Plastic greenhouse; short cycle",
    "intervention": "Supplemental lighting with CO2 enrichment",
    "comparator": "Ambient light and CO2",
    "dose": "",
    "dose_unit": "",
    "limitations": "Short (43 d) cycle, not a full high-wire Canadian crop. Electricity and CO2 prices will change the income ratio.",
    "source_year": 2024,
    "doi": "10.1007/s13580-024-00638-y",
    "baseline": "",
    "factor_id": "cucumber-led-co2-combo",
    "crop_id": "cucumber",
    "factor": "Supplemental lighting plus CO2 enrichment",
    "factor_category": "Light",
    "direction": "positive",
    "effect_type": "yield_gain",
    "evidence_type": "greenhouse_trial",
    "evidence_strength": "Moderate",
    "prairie_relevance": "moderate",
    "source_title": "Supplemental lighting and CO2 enrichment on the growth, fruit quality, and yield of cucumber (Horticulture, Environment, and Biotechnology 2025)",
    "notes": "One of the few cucumber papers that reports both yield and a simple income ratio. 111% income is not 11% net margin after capital recovery."
  },
  {
    "effect_size": 19.0,
    "effect_unit": "%",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "Two adjacent greenhouses. Enrichment to ~700 µmol mol⁻¹ when closed and 350 when vented. Fresh and dry fruit production +19%; radiation-use efficiency +14%. Most extra biomass went to fruit, not LAI.",
    "study_count": 1,
    "comparison_count": null,
    "source_url": "https://www.sciencedirect.com/science/article/abs/pii/S0308521X0400164X",
    "potential_yield_effect": 19.0,
    "geography": "Mild-winter greenhouse cucumber",
    "intervention": "Variable CO2 enrichment",
    "comparator": "Unenriched greenhouse",
    "dose": "",
    "dose_unit": "",
    "limitations": "Mild-winter climate; Alberta winter closed-house efficiency should be higher, summer venting similar or worse.",
    "source_year": 2005,
    "doi": "",
    "baseline": "",
    "factor_id": "cucumber-moderate-co2-19",
    "crop_id": "cucumber",
    "factor": "Moderate CO2 enrichment (~700 ppm closed / 350 ppm vented)",
    "factor_category": "CO2 / carbon availability",
    "direction": "positive",
    "effect_type": "yield_gain",
    "evidence_type": "greenhouse_trial",
    "evidence_strength": "Moderate",
    "prairie_relevance": "moderate",
    "source_title": "Effect of variable CO2 enrichment on greenhouse production in mild winter climates (Sánchez-Guerrero et al.)",
    "notes": "Agrees with the cucumber meta-analysis mean (~22%). CO2 use efficiency was low (~6% of injected CO2 recovered in fruit), so leaky houses waste gas."
  },
  {
    "effect_size": 22.8,
    "effect_unit": "%",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "Open-field meta-analysis, 180 studies, >1000 paired observations. All biostimulant categories averaged +17.9% yield; vegetables were the most responsive crop group (+22.8%). Highest under arid climates and poor soils. Soil application outperformed foliar on average.",
    "study_count": 180,
    "comparison_count": null,
    "source_url": "https://doi.org/10.3389/fpls.2022.836702",
    "potential_yield_effect": 22.8,
    "geography": "Global open-field trials",
    "intervention": "Non-microbial plant biostimulants",
    "comparator": "Untreated field crop",
    "dose": "",
    "dose_unit": "",
    "limitations": "Open field only. Do not transfer +22.8% to soilless high-wire cucumber without a greenhouse trial.",
    "source_year": 2022,
    "doi": "10.3389/fpls.2022.836702",
    "baseline": "",
    "factor_id": "cucumber-vegetable-biostimulant-meta",
    "crop_id": "cucumber",
    "factor": "Non-microbial biostimulants (vegetable-crop mean; open field)",
    "factor_category": "Biostimulants",
    "direction": "positive",
    "effect_type": "yield_gain",
    "evidence_type": "meta_analysis",
    "evidence_strength": "Moderate",
    "prairie_relevance": "low",
    "source_title": "A Meta-Analysis of Biostimulant Yield Effectiveness in Field Trials (Li et al. 2022)",
    "notes": "Not a greenhouse cucumber trial. Use as a prior for soil/organic cucumber, not as a hydroponic slab expectation. Effects are highly product- and environment-specific."
  },
  {
    "effect_size": null,
    "effect_unit": "",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "2023 Alberta greenhouse survey. Cucumbers occupy the largest vegetable area in the province (76 of 135 vegetable acres in an earlier industry profile). In 2023, cucumber was among the crops with positive gross margin, return to unpaid labour, and return to investment. Labour, natural gas, and packaging were major cost items.",
    "study_count": 1,
    "comparison_count": null,
    "source_url": "https://open.alberta.ca/dataset/fbb2b0b5-53b9-4dbd-92b7-f37ec8ed9369/resource/f4313ce0-1ea0-45e0-bc34-18306b1d2128/download/agi-economics-production-marketing-greenhouse-crops-2023.pdf",
    "potential_yield_effect": null,
    "geography": "Alberta",
    "intervention": "Observed cucumber enterprise",
    "comparator": "Other Alberta greenhouse crops in the same survey",
    "dose": "",
    "dose_unit": "",
    "limitations": "Blended survey, not a treatment trial. Area and price vary by year.",
    "source_year": 2025,
    "doi": "",
    "baseline": "",
    "factor_id": "cucumber-agriprofits-returns",
    "crop_id": "cucumber",
    "factor": "Alberta AgriProfit$ 2023 cucumber cost and returns",
    "factor_category": "Economics & Certification",
    "direction": "positive",
    "effect_type": "other",
    "evidence_type": "economic_benchmark",
    "evidence_strength": "High",
    "prairie_relevance": "high",
    "source_title": "Economics of Production and Marketing of Greenhouse Crops in Alberta 2023 (Laate)",
    "notes": "Cucumber is Alberta's dominant greenhouse vegetable. Yield-boosting CO2/light investments should be scored against this COP, not against an Ontario 60–70 kg/m² tomato house."
  },
  {
    "effect_size": 11.0,
    "effect_unit": "% (upper of 5–11% tomato/cucumber WUR range)",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "Wageningen comparative studies: cucumber under diffuse glass produced heavier fruit (+10–15 g) and more fruits; tomato and cucumber production +5–11%. Commercial paired houses (cucumber, tomato, cherry tomato) had ~8% higher radiation-use efficiency under diffuse roofs and no extra energy use.",
    "study_count": 5,
    "comparison_count": null,
    "source_url": "https://www.hortidaily.com/article/6001456/diffuse-glass-not-a-myth-but-clear-as-glass/",
    "potential_yield_effect": 11.0,
    "geography": "Netherlands high-latitude glasshouses",
    "intervention": "Diffuse covering",
    "comparator": "Clear glass",
    "dose": "",
    "dose_unit": "",
    "limitations": "Primary WUR reports are institutional; commercial RUE paper is WUR 2021 (10.18174/556873). The +11% is the top of the reported range, not a cucumber-only mean.",
    "source_year": 2012,
    "doi": "",
    "baseline": "",
    "applicability": "near-direct",
    "evidence_tier": "B",
    "factor_id": "cucumber-diffuse-glass",
    "crop_id": "cucumber",
    "factor": "Diffuse greenhouse glass",
    "factor_category": "Climate",
    "direction": "positive",
    "effect_type": "yield_gain",
    "evidence_type": "greenhouse_trial",
    "evidence_strength": "High",
    "prairie_relevance": "high",
    "source_title": "Diffuse glass production effects on tomato and cucumber (Dueck, Hemming, Janse; WUR Greenhouse Horticulture)",
    "notes": "Cucumber responded with both heavier fruit and more fruit. High-latitude light distribution is the mechanism — relevant to Alberta winter/spring."
  },
  {
    "effect_size": 16.8,
    "effect_unit": "%",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "Greenhouse cucumber fertigation × grafting factorial. Grafting onto C. moschata × C. moschata (G1) +16.8% yield vs non-grafted; Lagenaria siceraria (G2) +9.2%. Best fertigation × G1 combination +45.3% vs control. Separate soilless trial: Nagene on Shintoza plus AMF 2116 g/plant vs 1570 g ungrafted non-mycorrhizal (+35%).",
    "study_count": 2,
    "comparison_count": null,
    "source_url": "https://doi.org/10.3390/horticulturae10101135",
    "potential_yield_effect": 16.8,
    "geography": "Greenhouse soilless cucumber",
    "intervention": "Grafting onto C. moschata hybrid rootstock",
    "comparator": "Non-grafted cucumber",
    "dose": "",
    "dose_unit": "",
    "limitations": "Not Alberta. Quality (taste) can change with some cucurbit rootstocks.",
    "source_year": 2024,
    "doi": "10.3390/horticulturae10101135",
    "baseline": "",
    "applicability": "near-direct",
    "evidence_tier": "B",
    "factor_id": "cucumber-grafting-moschata",
    "crop_id": "cucumber",
    "factor": "Grafting onto Cucurbita moschata interspecific rootstock",
    "factor_category": "Genetics",
    "direction": "positive",
    "effect_type": "yield_gain",
    "evidence_type": "greenhouse_trial",
    "evidence_strength": "Moderate",
    "prairie_relevance": "moderate",
    "source_title": "Optimizing Greenhouse Cucumber Fertigation Through Grafting (Horticulturae 2024)",
    "notes": "Grafting is the standard Fusarium/Pythium and vigor tool where soil or reused slabs are used. Do not add the +16.8% grafting main effect to the +45% best-combination figure."
  },
  {
    "effect_size": 92.0,
    "effect_unit": "% fruit yield vs untreated mildewed control (B. subtilis)",
    "ci_lower": null,
    "ci_upper": null,
    "conditions": "Greenhouse cucumber with powdery mildew. Untreated control 1.82 kg fruit/plant. B. subtilis 3.50 kg/plant (+92%); chemical fungicide 3.65 kg (+101%). Fruit number +51% (Bacillus) to +59% (fungicide) vs untreated. Disease severity and AUDPC also fell.",
    "study_count": 1,
    "comparison_count": null,
    "source_url": "https://doi.org/10.1186/s41938-020-00267-4",
    "potential_yield_effect": 92.0,
    "geography": "Greenhouse cucumber (epidemic trial)",
    "intervention": "Bacillus subtilis (or fungicide) sprays on mildewed plants",
    "comparator": "Untreated powdery-mildew epidemic",
    "dose": "",
    "dose_unit": "",
    "limitations": "Single-location epidemic trial. +92% must not be read as a biostimulant premium on a clean crop.",
    "source_year": 2020,
    "doi": "10.1186/s41938-020-00267-4",
    "baseline": "",
    "applicability": "direct",
    "evidence_tier": "B",
    "factor_id": "cucumber-powdery-mildew-yield-recovery",
    "crop_id": "cucumber",
    "factor": "Powdery mildew (Podosphaera xanthii) — yield recovery with biocontrol vs untreated epidemic",
    "factor_category": "Disease management",
    "direction": "positive",
    "effect_type": "yield_gain",
    "evidence_type": "greenhouse_trial",
    "evidence_strength": "Moderate",
    "prairie_relevance": "high",
    "source_title": "Biological control of cucumber powdery mildew (Podosphaera xanthii) under greenhouse conditions (2020)",
    "notes": "This is yield recovery from a diseased control, not a gain versus a healthy crop. It documents how large the mildew yield leak can be. A Canadian high-wire pooling study is still a research gap."
  }
]