After one of the toughest seasons in living memory for growers, biostimulants Bridgeway and Zonda could offer a last ditched attempt to salvage profitability, according to the latest advice from Interagro. Charlotte Cunningham reports.

For all milling varieties – regardless of group – Hagberg Falling Number, specific weight and protein are key quality characteristics, which all have a significant impact on the final product.

As the yields of milling varieties have increased in line with feed varieties, careful attention must be paid to crop nitrogen requirements, says Stuart Sutherland, technical manager at Interagro. “With wheat always using available nitrogen to create yield before building quality, if it is not in sufficient supply, growers will struggle to reach the point at which it is being used to increase grain protein content.”

After anthesis, the end of flowering in wheat, nitrogen is remobilised from senescing leaf and stem tissues to the developing grain, influencing grain protein content. Amino acids are the major form of nitrogen which is transported from the leaf to grain in wheat, and so supplementing this could prove to be a very savvy move this season, he adds. “Approximately 60–95% of the grain nitrogen at maturity relies on the remobilisation of amino acids stored in the shoots and roots of wheat before anthesis, which is influenced by nitrogen supply.

“Therefore, feeding the crop amino acids during grain fill offers the potential to improve quality – and possibly yield – by exploiting an improvement in nitrogen use efficiency.”

In a bid to facilitate this, Interagro’s biostimulant products – Bridgeway and Zonda – contain all amino acids required by plants in the L-isomer form which can be utilised, explains Stuart.  “Feeding wheat crops Bridgeway or Zonda not only increases protein supply to the crop, it also supplies it in the most efficient form for remobilisation to developing grain.

“This offers the possibility to not only increase yield, but to increase grain protein too.

“With pressure on farm profitability, the ability to reclaim yield and meet milling specification – against the backdrop of lower wheat production and higher premiums – could make up some shortfall in lost earnings as a result of the difficult season.

“In 2018, a drought stressed year for wheat crops much like this year, T3 applications of Bridgeway increased both quality and yield in commercial wheat crops.”

Agronomist experience

To test the theories, agronomist Kieran Walsh looked at the effects of Bridgeway in Skyfall winter wheat.

Treatments were applied at T1, T2 and T3, with crop health monitored throughout the season by taking leaf samples every two weeks to measure nutrient analysis, as well as assessing photosynthetic efficiency with a BRIX reader that measures sucrose.

The Bridgeway treated crop showed consistently higher macro and micro-nutrient levels despite the drought and heat stress and BRIX levels were 23-39% higher at every assessment throughout May and June.

“Despite the difficult season, the Bridgeway treated crop produced a 12.8% protein milling sample compared with the untreated crop at 11.7% protein,” says Kieran. “Bridgeway also increased and gave a more consistent yield, according to assessment from a combine yield meter. But for me, it was the grain analysis from treated crops that was really impressive, with increases in all the elements tested – with the exception of copper.”

Pushing yields with Bridgeway at T3

Hutchinsons agronomist, Sally Morris, set out to determine the benefits of Bridgeway using a tramline trial within a commercial crop of Relay feed wheat, near Melton Mowbray.

The 24m tramlines ranged from 534-570m in length – from the edge to edge – measured using GPS in the tractor.

Bridgeway was applied at T1 (1.0 l/ha), T2 (2.0 l/ha) and T3 (1.0 l/ha) on tramline one, at T1 (1/0 l/ha) and T3 (1.0 l/ha) on tramline two and tramline three received a single application at T3 (1.0 l/ha). Tramline four was assessed as an untreated control.

“It was a particularly difficult season on this heavy land site, clay with a low stone content,” explains Sally. “At T1 the crop was stressed due to waterlogging after the wet in early spring, and at T3 the opposite was true, with the crop suffering from drought stress.

“But against all odds, the tramline with the three treatments yielded significantly higher than the untreated tramline, with a 2.208 t/ha uplift in yield. All of the Bridgeway treated tramlines yielded higher than the rest of the field average and a single application of 1.0 L/ha of Bridgeway at T3 increased yield by +0.84 t/ha.”