Plant growth regulator applications are currently low on the list of spring priorities for slow growing winter wheat crops, but timing applications could prove crucial with crops expected to rapidly go through their growth stages once the weather warms up.
In South Lincolnshire, independent agronomist David Boothman of Boothmans Agriculture says that crops aren’t quite ready for the T0 fungicide application, which is when he would normally add the first PGR.
“Wheat is more than a week behind where it was last year,” he comments. “And although ground conditions are going to be good for travelling, most of these crops are still to receive their Atlantis (mesosulfuron + iodosulfuron). That’s the priority right now.”
Where workloads and logistics are going to make it difficult to get the T0 and first PGR on, there’s always the chance to use a more substantial mixture at T1, he points out.
“It’s not ideal, but it may happen on some farms this year. Compensatory growth, which is bound to occur, can be checked by PGRs applied after GS30/31.”
Growers who are in a position to put T0s on in the next 7-10 days should use a growth regulator which has activity at cooler temperatures, advises Mr Boothman. “There are a number to choose from, so check the label.”
In Hampshire, Steve Cook reports a similar situation. “Wheat has hardly started growing, so lodging isn’t on our minds. Crops are mostly approaching GS30; few have got to GS31 yet. Disease risk is low too.”
There’s still plenty of time for his usual strategy of adding a chlormequat/Moddus mix to the T0 spray. “There’s quite a big spray window for this application, so there’s no rush. The growing points are barely visible.”
Farms in his area also have quite a bit of Atlantis still to apply, which is taking priority over all other fieldwork.
“Fortunately, being a bit late with the T0 and first PGR split shouldn’t matter this season. It isn’t helpful to compare this year with the last two.”
Given the conditions, Mr Cook believes it is unlikely that T1s will be applied before the end of April.
In Suffolk, independent agronomist Tim Martin says that the lodging risk will only increase if spraying plans get badly disrupted.
“Being delayed by a fortnight wouldn’t be great, as growth regulators sit alongside the T0 application. But we’re not in that situation yet and disease levels are very low.”
But he warns that timeliness with PGRs is important, especially where crops are likely to go through the growth stages very rapidly. “That’s also relevant for some chlormequat products, as the cut-off dates can vary.”
In Norfolk, Andrew Melton of Frontier Agriculture says drilling of peas and sugar beet has been occupying growers since Easter.
“Only the most forward wheats are starting to receive T0s and the first dose of PGR,” he reports. “Lodging is easy to manage if you know the field history and the variety, any you can always alter the second PGR split if conditions change.”