25 February 2000

Boost roots to optimise yields

SPRAY-ON products can boost cereal root growth, reduce lodging and lift yields, according to trials run by a Cambs farmer and his local distributor.

Last year Axis root stimulant and new nutrient formulation Route lifted wheat yields by 0.4 and 0.6t/ha, respectively, boosting gross margin by £45-£28/ha (£18-£11/acre).

Robert Stacey who farms 143ha (350 acres) at Ramsey Forty Foot, near Ramsey, Cambs, normally expects first wheat yields of 8.9t/ha (3.6t/acre) on his fertile silty clay loams.

In the past he has had trouble keeping Abbot upright. "In 1997 every bit of Abbot lodged on the farm, going over at the base," he recalls.

In such a situation relying on PGRs alone is not enough, says &#42 L Hutchinsons regional agronomist Peter Fryer. "With 5 and 6 ratings for standing power Reaper and Abbot are not the strongest strawed varieties for a very fertile fenland situation. In wet soils in a wet summer, these varieties also tend to slump sideways, lodging at the roots rather than bending at the stem," he says.

Improving the growth and bulk of anchoring roots became a priority, Mr Stacey first trying Axis three years ago on a crop of Axona drilled in the first week of December. "We knew the variety was low-tillering and long-strawed and there was a clear difference in root growth where Axis was applied," he says.

Last year he tried Route, a new nitrogenous zinc formulation from Newman Agrochemicals, in a replicated trial in mid-November drilled Abbot.

Applied at early-tillering (GS 22) on Mar 17 it gave a 0.6t/ha (5.3%) yield response. Axis gave a 0.4t/ha yield response, although Mr Stacey reckons it could have done better from earlier treatment at 2-2.5 leaves.

Margin over cost for Route was £45.36/ha (£18.50/acre) based on the 11.9t/ha (4.9t/acre) crop selling at £90/t. Without a premium it would still have given a £32/ha (£13/acre) margin.

Plant assessments 22 and 54 days after treatment help explain the yield lift.

"Route and Axis produced more root mass than controls, so even in the absence of lodging this helped produce more yield," Mr Fryer says.

"In addition, the early applied Route produced more primary tillers per plant at the expense of less productive secondary tillers." Grain quality differences were minimal.

But timing was critical. Route applied at early stem extension produced less root and only 0.3t/ha extra yield, half the response from a GS22 timing.

"Route could be particularly useful in later-drilled crops from November onwards, especially those going into poorer, cloddier conditions after sugar beet or potatoes," says Mr Fryer. "Poorly emerged crops could also get an early dose, probably coinciding with either the BYDV, manganese or blackgrass spray."

Mr Stacey plans to repeat his trial, this time in Malacca.

"If Route continues to perform as it did last year, we will consider using it over the whole farm." &#42

ROOT IMPROVERS

Pleased with root boosting sprays…. Cambs farmer Robert Stacey (left) and &#42 L Hutchinson agronomist Peter Fryer plan to use them again this season.