Careful crop preparation now helps avoid lodging
Planning growth regulator programmes this season needs to take account of both a variety’s inherent weaknesses and growing conditions to make sure sprays are timed to minimise lodging risk.
Syngenta’s variety-profiling information on whether a variety needs strengthening to protect against root or stem lodging has helped refine growth regulator use according to need and likely response over the past four years, Andy Scott, technical manager for Bedfordshire distributor LW Vass, says.
Early splits (GS25-30) aimed at improving rooting and strengthening stem walls are critical for varieties such as Cordiale and Gladiator, which are inherently weak for root lodging and stem strength. But on forward crops where the early growth regulator is required there is a risk of creating excess tillers, so growers need to be sure tillering has finished before applying the early part of the split, he says.
“There is a case for delaying the half rate chlormequat/Moddus until GS30 so the weaker tillers have already been shed.”
But delaying does have its risks, he admits. Catchy weather to date emphasises the difficulties with spray timing. “A planned approach is fine, providing you can stick to the schedule.” But a well-timed T0 spray could buy growers some time with a follow-up spray, he suggests.
Most crops will need a growth regulator with the T1 fungicide around GS31-32, he says. That’s geared towards stem shortening and preventing stem lodging. “On varieties with good stem strength we’ll assess crops visually in April before making a final judgement.”
For single applications Mr Scott usually advises 0.2 litres/ha Moddus (trinexapac-methyl) + 1.25 litres/ha chlormequat, while the second half of a split treatment would either by 0.1 litres/ha Moddus + 1.25 litres/ha CCC, or 0.2 litres/ha Moddus.
Other agronomy factors also have to be considered in any lodging management decision, he stresses.
“Soil type is a key factor because it has an effect on anchorage. The difference between a light, puffy soil and a strong, clay one can be enormous. Soil condition also plays a part – a compacted soil won’t allow the roots to grow down well.”
Potential yield, nitrogen inputs and rotational place are further influences on lodging, he notes.
But healthy grain prices are persuading growers to look after their crops, he says. “People feel more comfortable spending between £6 and £18/ha on growth regulators when they are guaranteed to see a return.”
