Independent review of Allgrow
Grobruket AB tested Allgrow against a control on white mustard, with statistical analysis, and reached the same conclusion as our own trials: a low dose helps, a high dose harms. The full report is downloadable at the foot of this page.
Grobruket kan baserat på dessa resultat verifiera Allgrow som en växtbiostimulant med avseende på positiv påverkan på rotarkitektur och rotutveckling vid låg dos, inom ramen för tidig groning och etablering.
Niklas Hjelm, horticultural engineer, Grobruket AB. From the conclusion of the report, 13 February 2026.In English: on the basis of these results Grobruket verifies Allgrow as a plant biostimulant with respect to a positive effect on root architecture and root development at low dose, within early germination and establishment.
How the trial was set up
- White mustard (Sinapis alba), 50 seeds per arm, three arms: water control, 3 % Allgrow and 10 % Allgrow.
- Seeds were placed on germination paper rolled into vertical wicks standing in the solution, giving continuous exposure by capillary action.
- Measured on day 10. The period was kept deliberately short so that Allgrow's own nutrient content would not have time to influence the result.
- Differences were tested with the Mann–Whitney U test at the five per cent level. Data are reported as medians with interquartile range, because the measurements were not normally distributed.
Results, median per arm
| Control | 3 % Allgrow | 10 % Allgrow | |
|---|---|---|---|
| Lateral roots (count) | 4 | 9 | 1,5 |
| Root index | 4,3 | 12,9 | 1,7 |
| Total root length (mm) | 13,5 | 10,7 | 6,2 |
| Longest root (mm) | 12,1 | 8,1 | 5,9 |
| Shoot growth (cm) | 3,1 | 3,5 | 4,4 |
| Germinated seeds | 44/50 | 45/50 | 48/50 |
What the figures mean — and what they do not
- At 3 % the number of lateral roots more than doubled against the control, and the root index tripled. Both differences were statistically significant.
- The control had longer roots at the same time. Allgrow did not produce more root mass but a differently built root system: more and shorter roots, meaning greater contact area with the soil. Branching is the point, not length.
- At 10 % everything got worse — fewer lateral roots than the control, lower root index, shorter roots. Also statistically significant. It is the same dose ceiling our own trials show, found independently of us.
- At 10 %, on the other hand, shoots and leaves grew most. The report warns against reading that as a good sign: a plant investing in leaf mass on a weakened root system runs into trouble later.
- This concerns early germination and establishment in white mustard, in a laboratory set-up. It says nothing about yield, and nothing about what happens in a field.
Sources
The full report (PDF)
Grobruket's own article about the trial
Grobruket AB is an independent horticultural advisory firm. They hold no stake in Allgrow, and the report was commissioned and paid for as an assignment.
What next?