Crop trial by American Pacific Borates shows boron-boosted sulphate of potash fertiliser can improve growth and yield

American Pacific Borates (ASX: ABR) has reported positive results from an independent crop trial of its boron-enriched sulphate of potash (SOP+B) specialty fertiliser using product from its Fort Cady borate mine in California.

Conducted by the University of Connecticut, the trial aimed to evaluate the growth and yield performance of broccoli and tomato crops planted in May using four different blends of the fertiliser alongside the grower’s conventional fertilisers (which did not contain boron).

It was designed on a randomised basis with four replications of blocks, each measuring 3.65 metres x 1.8m over a total trial area of approximately 2000 square metres.

Plant height was measured in 15 day intervals and assessments made on marketable fruit or head yield, soil condition before and after the application of treatments, and tissue quality during the middle of the growing season.

The final crop trial report was prepared by Dr Shuresh Ghimire who specialises in vegetable crops as an extension educator at the university’s Tolland Agricultural Centre.

Trial results

The broccoli trial showed significant benefits from the use of boron-enriched SOP, revealing a notable uptake of boron in the crops which resulted in dramatic yield improvements.

Application of American Pacific’s Proprietary Blend B fertiliser delivered the highest yield compared to the grower’s standard SOP fertiliser.

The tomato trial became more positive as the growing season progressed and with the use of blends containing higher concentrations of boron.

Results suggested a linear correlation between boron ratio and yield performance, which was not evident in the broccoli crop.

Tomato yield increased by around 10% using American Pacific’s Proprietary Blend D, which the company claimed to be a significant finding in the context of the trial.

The grower also noted increased vigour and colour from the boron-enriched tomato plants.

Alternative fertiliser

Managing director Michael Schlumpberger said the company would be targeting the SOP+B product as a potential alternative fertiliser in the large US market.

“These results start to validate the thesis that our boron-enriched SOP could potentially transform the North American specialty fertiliser market,” he said.

“To see broccoli yields more than double with the use of SOP+B was amazing and will give us a major competitive advantage in the market as it can be produced on-site without any double handling or logistical burdens.”

He said further tomato crop trials would be conducted to quantify the benefit of boron-enriched SOP fertiliser on head or fruit quality and the post-harvest life of broccoli and tomatoes, as well as to optimise the boron-enrichment ratio within the fertiliser.

Ideal candidates

Broccoli and tomato are believed to be ideal candidates for a boron-enriched SOP fertiliser as they are sensitive to the chlorides found in common fertilisers, yet require potassium and boron as essential micronutrients.

It is also generally believed that test results for broccoli will apply to other cruciferous crops such as kale, cabbage, cauliflower and brussel sprouts.

California accounts for 92% of all broccoli grown in the US and 90% of all tomatoes.