23 UK Onion Field Trials (2022–2025)
Trial data
Yield, margin and application protocol results from commercial crops
Between 2022 and 2025, Maxstim Agriculture+ and Cynosa™ were evaluated in 23 UK onion field trials conducted under standard commercial growing conditions.
The 23 UK onion field trials covered:
- 22 sown onion trials
- 1 onion set trial
- 8 commercial varieties
- 4 application protocols
- Six replicated treated and control plot pairs per trial
Across the full 2022–2025 dataset, statistical analysis shows a 99.98% certainty that treatments were effective (Chi Square value 15.69, p = 0.0001).
This represents four seasons of replicated commercial field performance.
Summary of results (2022–2025)
Across the 23 UK onion field trials conducted between 2022 and 2025:
- 5.73 t/ha average increase in marketable yield (50mm–80+mm grades)
- £350–£600 per hectare typical margin increase after product cost
- Up to £2,500 per hectare margin increase recorded in 2025, depending on application protocol
- 25.2% highest total yield increase recorded (tape irrigation protocol)
- 99.98% statistical certainty across the full trial programme
Marketable yield was assessed strictly in grade sizes 50mm–80+mm. Margin calculations were based on £220/t for red onions and £200/t for brown onions entering storage, with product cost deducted before quoting uplift.
Yield performance by crop type
Brown onions – conventional spray (8 trials)
Within the 23 UK onion field trials, eight brown onion crops were treated using conventional spray applications (2022–2025):
- Control yield: 44.7 t/ha
- Treated yield: 48.6 t/ha
- 8.7% total yield increase
- 3.88 t/ha average marketable yield increase
- £342 average margin increase after cost
- 7.36% increase in plant number per hectare
Red onions – conventional spray (10 trials)
Ten red onion trials under conventional spray recorded:
- Control yield: 43.3 t/ha
- Treated yield: 49.2 t/ha
- 13.7% total yield increase
- 5.92 t/ha average marketable yield increase
- £868 average margin increase after cost
- 5.63% increase in plant number per hectare
Across the 23 UK onion field trials, red onions recorded a higher percentage uplift than brown onions under conventional spraying.
Application protocol comparison
A key strength of the 23 UK onion field trials is the comparison of four delivery systems under commercial conditions.
Tape irrigation – brown onions (2 trials)
- Control yield: 53.0 t/ha
- Treated yield: 67.1 t/ha
- 25.2% total yield increase
- 14.1 t/ha average marketable yield increase
- £2,639 average margin increase after cost
- 21.7% increase in plant number per hectare
This was the highest uplift recorded across the 2022–2025 onion trial programme.
Ecorobotix precision sprayer – red and brown onions (2 trials)
- Control yield: 58.3 t/ha
- Treated yield: 62.4 t/ha
- 7.05% total yield increase
- 4.09 t/ha average marketable yield increase
- £638 average margin increase after cost
- −1.59% change in plant number per hectare
Precision spraying delivered measurable yield uplift, with differing plant population response compared to other protocols.
Onion sets – conventional spray (1 trial)
The single onion set trial within the 23 UK onion field trials recorded:
- Control yield: 45.8 t/ha
- Treated yield: 60.2 t/ha
- 14.4% total yield increase
- 14.4 t/ha average marketable yield increase
- £2,510 estimated margin increase after cost
- 11.1% increase in plant number per hectare
Trial methodology
Each of the 23 UK onion field trials compared Maxstim Agriculture+ and Cynosa™ with standard farm practice.
Yield plot assessments consisted of six replicated treated and control plot pairs, sized 3.66m², 3.0m² or 2.745m².
Data recorded included:
- Plant number per hectare at harvest
- Number of onions in grade sizes 50mm–80+mm (10mm increments)
- Weight of onions in grade sizes 50mm–80+mm (10mm increments)
Eight varieties were included across the programme:
- Donna
- Numbito
- Hytech
- Julia
- Nation
- Red Baron
- Red Garnet
- Red Tide
Four seasons of commercial field performance
Taken together, the 23 UK onion field trials conducted between 2022 and 2025 provide four seasons of replicated commercial data showing:
- 5.73 t/ha average uplift in marketable grades 50mm–80+mm
- Margin increases calculated after deduction of product cost
- Plant population improvements under multiple protocols
- Variation in outcome depending on application system
- 99.98% statistical certainty across the full dataset
For growers reviewing input performance over time, the 23 UK onion field trials (2022–2025) provide a structured record of yield, establishment and margin outcomes under standard farm practice.
23 trial onion dataset (2022-2025)
The complete 23-trial onion dataset is available to download.
Key results include:
- 5.73% average yield increase: Marketable yields showed consistent growth across trials.
- Higher margins: Growers saw additional margins of £350–£600/ha.
- Equivalent to $263–$444/acre.
- Reliable yield increase of marketable grades 50mm – 80mm+.
Trial data results
These results, achieved with a Maxstim protocol, demonstrate how cutting-edge biostimulant technology can help onion growers enhance yield, boost profitability and improve sustainability.
Chat with one of the team below to find out how Maxstim can transform your onion production.
Canada:
David Klassen
Email: davidklassen@maxstim.ca
Call: 604-203-7604
Johny Shajahan, Ph.D
Email: johnyshajahan@maxstim.ca
Mobile: 6519-808-9797
UK:
Tim Cannon
Email: tim.cannon@maxstim.com
Mobile: 07884 586191
Phil Kingsmill
Email: phil.kingsmill@maxstim.com
Mobile: 07860 269996
Leanne Taylor
Email: leanne.taylor@maxstim.com
Mobile: 07552 097554
Tony Kelly
Email: tony.kelly@maxstim.com
Mobile: 07974 435417
