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Top Tips for managing cereal and oilseed rape crops

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Top Tips for managing cereal and oilseed rape crops

29/05/2015

Article taken from the North-east Farmer, written by Jane Craigie

Jane Craigie
quizzes Agrovista's North-east agronomist, Stewart Rothnie, about his recommendations for cereal and oilseed rape (OSR) crops over the coming months.

Q: Winter crops went in well but it’s been dry followed by the recent cold snap.  What will this mean for crops?

Cold and dry weather generally doesn’t pose too much of a problem for overwintered cereal nor oilseed rape crops.  The recent cold snap has kept growth in check but as day length starts to extend, despite it having been relatively dry during April, there is adequate moisture for normal growth from now on.

Winter barley has gone through some growth stages despite the cold and some crops in Moray have awns visible.  Some of our early sown spring barley stayed underground for what seemed a long time but it hasn’t been disadvantaged in my view.

The upside of the cold weather is that it has kept insect pest levels in winter OSR to a minimum but remember that they can flourish to threshold levels very quickly and need to be carefully monitored, especially if you have taken the decision not to treat.

Q: What are you recommendations for T1 and T2 in wheat and barley?

For winter barley, I’m recommending our strobilurin + Triazole mix (Jaunt) at both T1 and T2.  For those seeking an SDHI option, I’m suggesting a reduced rate of Cebara or Librax is added to the Jaunt.  For growth regulator, I’d Canopy at T1, which I feel gives the growth regulation needed without too much crop effect.  I’d suggest at top up with ethephon + CCC (Vivax) at GS39 as required.  At T2, we will add a multisite inhibitor, Folpet, as Arizona for both Ramularia and resistance management, ideally at GS49.

For winter wheat, most of my customers will have applied penthiopyrad + chlorothalonil as Fielder for both mildew and Septoria control.  At T1, most will apply an SDHI + strobilurin + triazole as Variano Xpro along with chlorothalonil plus Canopy + CCC for growth regulation.  At T2, I’m recommending a SHDI + triazole as Librax + Ennobe.

This will leave an option of a second strobilurin as asoxystrobin at T3, which for our extended heading period typically gives us a good response in both yield and grain quality.  Fertiliser rates are dictated to be within NVZ rules so winter barley should get a maximum 140kg N while winter wheat could get up to 160kg N.  It would be difficult to justify anything greater than this in my view.

Q: What are your recommendations for oilseed rape crops?

Quite a lot our winter OSR had a backend Light Leaf Spot spray in the farm spray store but in many cases it wasn’t possible to apply it.  Most have now applied that as soon as they could in the spring, almost all with pentiopyrad + picoxystrobin as Frelizon.  In addition, boron and molybdenum has been applied as Headland Bo-La.

The early flowering spray that I’ve been recommending includes picoxystrobin as Galileo in tank mix with TerraSorb to aid flowering.  Three weeks after the early flowering spray, I’m advising application of flyopyram + prothioconazole as Recital.  This will probably get a spray for seed weevils.  Fertilisers will max out at 160kg N, although we have some that will save a little for foliar NufolS with the second flowering spray sprayed on to the pods to deliver 10kg N.

Q: What are your points to watch for all crops over the coming month to six weeks?

Leatherjackets in cropped fields following grass.  I’d also like to remind growers about sprayer hygiene when moving between susceptible crops, especially with more cropping variation and fallow due to the new rules.  There could be scenarios which have been alien to some growers for some time with swede or peas mix, for example, in the rotation.

Maintaining reasonable spray intervals so as not to leave unduly long spells between key fungicides, with three weeks being the target.

Most of the popular spring barleys grown are mildew resistant, such as Concerto and Propino, but they are all prone to Rynchosporium.  Whilst we have not been too troubled with this disease in the last couple years, we need to remain vigilant and protect from likely risk.  Similarly, whilst we are not in a rust hotspot here in the North-East, all of our wheat will take Septoria and this needs treatment as a priority.

We are also ‘sclerotinia central’ in North-east OSR crops because of extended flowering periods and a high host rotation because of other brassicae host weeds and clovers being grown in the area.

Q: With current low market prices, where should growers invest and where out?

As an agronomist, it could be seen as negligent or roguish just to leave out a key spray to save some cost in 2015 having adamantly recommended such a spray in the past.  We appreciate combinable crop margins don’t look too rosy but optimum yield and quality are bigger drivers in the main markets that we grow for in this region.

We cannot compromise on disease control.  Rhyncosprium in winter and spring barley can decimate both yield and quality.  Septoria in winter wheat will do the same, as will sclerotinia in oilseed rape.  We could probably live with a few more weeds if our growers are happy to do so (not beside the road though!).  Having said that, the penalty for admixture in oilseeds are high and cereals going to malting can be rejected for weeds seeds.  So heed caution here too.

It’s a difficult decision to make.  You don’t really want to be scraping your good crops off your fields so to compromise on growth regulator could be costly.  It in doubt, don’t apply as much fertiliser.  The benefits of maintaining good crop health can make the cost of growth regulator look good value.

Look after the crop you have in the ground to maintain yield and quality would be my advice.