Recently, our research team conducted a controlled-environment germination experiment in Yandina, Queensland, to evaluate the effects of various commercial biostimulant products on early crop establishment. The trial was designed to compare the early-stage performance of Tygrus Growthful and Nutri-Tech Solutions (NTS) products against an untreated control to determine whether they could enhance germination, seedling vigour, and root biomass in Yates-brand cos lettuce.

Here is a look at how the trial was set up, the surprising results, and what it means for growers.

The Trial Setup 

To ensure a reliable comparison, seeds were sown in a standard germination medium under consistent temperature and moisture conditions. The lettuce seeds were divided into four treatment groups:

• Control: Seeds were soaked only in tap water with no further treatments applied.
• Growthful Pre-Emerge: Seeds were planted in the soil, and a 1:25 diluted Growthful solution was sprayed onto the soil.
• NTS1 (Seed Soak): Seeds were soaked in a mixture of Root & Shoot, BAM, and Platform for one hour before planting.
• NTS2 (Soil Spray): Seeds were planted directly, followed by a soil spray of the Root & Shoot, BAM, and Platform mixture.

The Germination Race: A Surprising Winner 

Cos lettuce seeds germinate quickly, with the majority of seeds in this trial emerging by Day 3 and all final germination achieved by Day 6. Interestingly, the untreated control outperformed the commercial biostimulants in this phase.

The Control group achieved the highest final germination rate at 93.3%. The NTS2 soil spray and Growthful treatments tied for second, both reaching an 83.3% final germination rate. The NTS1 seed soak recorded the lowest final germination at 80.0%. While the NTS2 treatment showed the fastest early emergence by reaching 73.3% germination on Day 3, its final numbers still remained below those of the untreated seeds.

Shoot Growth vs. Root Biomass 

This trend continued above the soil during the seedling vigour assessment. The Control group produced the tallest plants, boasting a mean shoot height of 134.3 mm. In comparison, NTS2 averaged 119.1 mm, Growthful averaged 115.5 mm, and NTS1 averaged 107.1 mm. None of the seed treatments improved the shoot growth of the lettuce.

However, when looking below the soil, the treatments showed their potential. The NTS2 soil spray promoted the greatest root development, achieving a root biomass of 0.25 g. This represented a 19% increase over the untreated control, which had a root biomass of 0.21 g. The NTS1 soak slightly improved root biomass to 0.22 g, while the Growthful treatment produced root biomass equivalent to the control.

Key Takeaways for Growers 

Following the early seedling measurements, the lettuce plants were transplanted into a ginger bed at a farm in Eerwah Vale to grow to maturity.

So, why did the untreated seeds win the germination and shoot height race? 

The trial results suggest that very small seeds, like lettuce, may be sensitive to seed or soil-applied treatments during early germination. Treating small seeds during planting might introduce early stress.

For growers working with small-seeded crops, the main takeaway is to adjust your application timing. Rather than applying biostimulants directly at sowing, it is better to wait until after emergence, specifically after the third leaf has appeared, to avoid stressing the early seed.

Root & Shoot™

Promotes vigorous root growth and luxurious shoot development.

Root & Shoot™ is a new formulation specifically designed to promote rapid establishment in transplanted crops (vegetables, strawberries, tree crops). This product can also be used as a very effective “rescue remedy” during times of stress (frost, hail damage, heat, wind, transplant. Root & Shoot™ has also proven to be a valuable tool for promoting vigorous shoot development across all crops.

Key Performance

• Improve root growth
• Enhance shoot production
• Broad-spectrum nutrition

Nutri-Life BAM™

Multipurpose blend of anaerobic species for soil, compost and plant health.

This breakthrough probiotic blend contains lactic acid bacteria and purple non-sulphur bacteria, plus beneficial yeasts and microbial exudates.

To order or learn more, call NTS on (07) 5472 9900 or email sales@nutri-tech.com.au.

Certificate in Nutrition Farming

Our next iconic, five-day Certificate in Nutrition Farming® course is scheduled for November 2026: Monday 2nd - 6th.

Our last course was attended by growers and consultants from six countries. It was a wonderful learning opportunity where attendees enjoyed a wealth of education and inspiration from both our presenters and their fellow attendees. We only accept 40 bookings for these courses, so please register if you would like to attend.