View full trial documentation and photos here
In light of the increasingly strict global regulations regarding the use of plant growth regulators (PGR’s), we aimed to evaluate alternative solutions.
This trial focused on assessing the response of Lobularia to several commonly used PGRs: CCC, Alar, and Cultar.
Lobularia requires effective growth control treatments in order to achieve a compact, high-quality appearance that meets market standards and performs well in small pots.
The goal was to observe and compare the visual impact and growth habits resulting from each treatment, in order to identify effective and compliant options.
The trial included Danziger’s Stream and Stream Compact series, which were evaluated under the different PGR treatments in 3 separate groups.
PGRs Comparison:
| Parameter | ALAR – Daminozide (85%)
(Spray) |
CCC – Chlormequat chloride (70%) (Spray) | Cultar – PACLOBUTRAZOLE (250gr/L) |
| Growth Suppression Strength | Mild to Moderate | Moderate | Very Strong |
| Ease of Use | Forgiving, low risk of overuse | Moderate precision required | Requires high precision |
| Crop Safety (Phytotoxicity) | Very Safe | Medium – Risky in high temperatures and concentrations | Medium – Risky in high concentrations |
| Market Price | High | Low | Low |
| Duration of Effect (depend’s on crop sensitivity) | Short (few weeks) | Short (1-2 weeks) | Long (4+ weeks) |
| Required Concentration | 1-3 gr\L = 1000-3000PPM | 1.25-3.75 ml\L = 500-1500PPM | Drench – 0.125-0.5PPM
Spray – 1.25-5PPM **Requires prior dilution |
Cultivation process:
| Week Number | Action |
| 6 | Sticking |
| 9 | Pinching |
| 9 | Planting |
Results:
Plant’s Growth effect:
The results clearly demonstrate the effectiveness of growth regulation treatments across Danziger’s Lobularia varieties. The response was particularly noticeable in the Stream series, known for its more vigor growth habit.
Among the tested compounds, Cultar and CCC showed strong PGR effects, achieving desirable plant form with relatively few applications, while Alar had minimal impact and did not result in significant growth reduction.
Foliage effect:
CCC induced leaf edge chlorosis, possibly indicating mild phytotoxicity and\or to high concentrations used in this cultivation.
Flowering Effect:
CCC negatively affected flowering performance and mechanical strength.
While Alar had no noticeable PGR effect, a distinct difference was observed in flower color, particularly in the non-white varieties: flowers in the Alar-treated group appeared more vivid compared to the lighter tones seen in the Cultar and CCC treatments.
