How to keep winter wheat standing tall - farmers weekly

22 FEBRUARY 2002 ------------------------- HOW TO KEEP WINTER WHEAT STANDING TALL KEEPING THIS SEASONS WINTER WHEATS STANDING PROMISES TO BE A TOUGH CHALLENGE. EDWARD LONG ASKS CROP

SPECIALISTS FOR ADVICE ON HOW TO COMBAT THE PROBLEM SOME wheats are facing the highest ever lodging risk this season, and whether they stay upright or fall depends on nitrogen and growth

regulator use. "There is a massive risk due to a lot of early drilling at inappropriately high seed rates," says Hutchinsons agronomist Dick Neale. Any September-sown crop with

more than 100 plants/sq m is very likely to go down if strict guidelines are not followed. The first step is to avoid early nitrogen to allow weak tillers to die, he advises. No N should go

on until crops are under control, and first input should be growth regulator at stem extension (GS30). East Anglian wheats drilled in September at 125kg/ha will reach that stage about Mar

10-15, he estimates. Earlier treatment will just encourage unwanted tillers. High populations of tall plants with thin floppy stems need regulator priority. Mr Neale suggests Meteor

(chlormequat + choline chloride + imazaquin) or Moddus (trinexapac-ethyl) + chlormequat, because Moddus works well in cool conditions. Follow-up applications should be made at first node

(GS31) – about Apr 1, but within three weeks. Early drilled wheats may look hungry because of plant competition, but they have good root systems and there is no shortage of available soil N,

says Mr Neale. "So do not be fooled into giving them a little N to green them up. If the growing point is dark green the plant is not starved." Be sure to tailor pgrs to variety

and drilling period, advises Syngentas Jason Tatnell. "Crops are more vulnerable this season, and the two most widely grown varieties – Claire and Consort -have their own specific

weaknesses. "Claire and Consort account for about 50% of the UK crop. We know early drilled Claire can become tall and prone to lodging, while Consort tends to develop a weak stem

base." An appropriate pgr programme can make September-drilled Consort behave like September-sown Equinox or Consort drilled in November, he says. "In this way growers can enjoy

the yield benefits of earlier sowing without the increased risk of lodging." For an early sown "at-risk" variety, he advises a belt-and-braces strategy with Moddus at the end

of tillering to boost rooting followed by a mixture of Moddus + chlormequat at first node to strengthen stems and reduce height. There is no need for Claire to lodge, says Nickerson breeder

Bill Angus. "Control must be based on a multi-pronged approach. It is vital to get the seed rate, pgr type and timing, plus nitrogen rate and timing right. If any one is wrong there

could be trouble." Early N causes problems because it increases inter-node length. "If the crop turns yellow ignore it." No N should be applied until terminal spikelet stage,

which for first wheat is usually mid-April. A simple pgr approach, a two-thirds dose of chlormequat at first node with one-third at GS31, is all that is required, he says. There is no need

for sophisticated products. Terpal (2-chloroehtylphsphonic acid + mepiquat chloride) can be applied later if crops are still at risk. &#42 Claire down rated For the 2002 Recommended

List, NIAB down-graded Claires straw strength rating from 8 to 7. "Claire has not suddenly become weaker," says Richard Fenwick. "It was always a marginal 8 and we think the

lower score reflects its ability to stand up in most seasons. "Claire is not as stiff as Consort, which retains an 8." LODGING CHALLENGE _&#8226 Highest-ever lodging risk._

_&#8226 Early pgr needed._ _&#8226 N applications must be delayed._ _&#8226 New lodging meter under test._