A series of replicated experiments over recent seasons to investigate responses to boron in winter wheat has been of particular interest to customers, says Frontier’s Jim Carswell.

“An application of boron – a low dose of Yara Phosyn’s Bortrac 150 – was applied between mid-February and mid-March around early stem extension in each season.

“Grain yield responses across the sites and seasons have been surprisingly consistent – from 0.15 to 0.18t/ha extra.”

Based on a feed wheat price of £88/t in October 2006, the additional output represents a net return of £10-£12/ha (£4-£4.90/acre), he calculates.The figures exclude application costs on the basis that boron would usually go on with a spring herbicide or early fungicide.

Significantly, the results were achieved at sites where the soil boron status was deemed as adequate – between 1.2 and 2.3ppm.”The main reason for the positive responses was probably that boron is generally less available on chalk or ‘over-limed’ soils.”

The calcium content of the soils at the trials sites was high (between 3000 and 9000ppm) against a guideline of 1600ppm.”The soil calcium may have acted as an antagonist to the uptake of boron from soil by the plant roots,” suggests Mr Carswell.

“Boron is generally seen as important in maximising winter oilseed rape yields.

“These results indicate that boron should also not be overlooked when considering trace element programmes in cereal production.”

Generally, farmer perception is that boron application to cereals could lead to toxicity, he says.

“However, such thinking is based on historic products (eg Solubor) and/or advice.

“The trials work has indicated that nowadays an appropriate low dose of a carefully formulated product, such as Bortrac 150, should be problem-free to the treated crop.”

Grain yield and quality responses to minor elements such as copper, zinc and boron as well as nitrogen and sulphur are being investigated across a range of varieties in winter wheat and barley, spring barley, winter and spring oilseed rape, and spring peas and beans, he says.

Quality

“We’ve been assessing the quality of the wheats. In 2003, for example, the off-combine specific weight was higher in the boron-treated samples in five of the seven varieties.

“The average without boron was 72.8kg/hl. Plus boron it was 73.6.”The varieties that year were Claire, Consort, Malacca, Robigus, Sabre, Savannah and Tanker.

There were no differences in Hagbergs or thousand grain weight, but the protein in the boron-treated samples was only 12.4% against 12.55% for the untreated.

“I put that down to the yield dilution effect,” says Mr Carswell, who says a key support function for the company is the “in-house”ability to conduct small plot trials including at a new site for autumn 2006 near Horningsea, Cambridgeshire.

“About 10,000 plots are drilled each year, covering some 35ha.”