Farm Ireland

Tuesday 20 March 2018

Decisions made earlier in the year are starting to pay off in the fields

Misconception: Septoria-like symptoms in winter oats in Athy, Co Kildare but it is believed to actually be Pseudomonas Syringea
Misconception: Septoria-like symptoms in winter oats in Athy, Co Kildare but it is believed to actually be Pseudomonas Syringea
Pat Minnock

Pat Minnock

AT THIS time of the year it can be a real pleasure to be in the fields, especially when management decisions made earlier in the year appear to have worked well.

Winter barley is a case in point. This crop is particularly clean this year and the decision to use some of the cheaper triazole chemistry earlier appears to have worked well and should help to keep costs down.

Most crops are clean to the floor and, while there are still approximately seven weeks to harvest, the last remaining fungicide is now due.

In many of my own crops I will be using a 3/4 rate SDHI and 1/2 to 3/4 rate of a combination product of triazole plus chlorothalonil.

There is some excellent value for money in combination products at the moment and growers should shop around.

It is not the price of the can that will save money but the choice of the product used. Different merchants feature different products, so there are lots of choices.

Winter wheat is a different matter. I am pleasantly surprised with the control levels achieved for septoria on most winter wheat crops. Most havefour good clean leaves, but there are still signs of septoria present. With the current weather conditions this septoria can be expected to progress and leaves will be lost. All wheat crops should have received, or be receiving, their T2/flag leaf fungicide at this stage.

If you have already used an expensive fungicidal programme and your crops are clean it may now be opportune to revert to triazole/combination products.

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However, as this is the most important application time (flag leaf) I would be slow to compromise and in most cases I would suggest using one of the SDHIs with chlorothalonil and a mildewicide, like Talius, for mildew prone varieties.

If crops look heavy and you are worried about lodging, this is the last opportunity to apply a growth regulator.

Cerone, or its equivalent, can be applied with the T2 before growth stage (GS) 47 at 0.6-0.75 litres/ha.

Winter oats also appear to be very clean except for some crops that have mildew present. I note some septoria-type damage on some crops (see attached photo) but consider this to be a bacterial infection, Pseudo-monas Syringae.

There is no chemical control for it but kresoxim-methyl containing products appear to have some beneficial effect.

Growth regulation appears to have worked very well. Most crops have heads emerging and now require their final fungicide. Again, a combination product of value should be considered but the use of a tebuconazole product (Folicur or Riza) will help grain colour.

Most crops of winter oilseed rape are at, or past, 95pc petal fall and should also be treated with their final fungicide. This can be a combination of products such as Amistar and Proline. Karate or Lambda should be included for seed weevil control, if required.

Growth has been rapid in spring barley crops and while later than average sowing occurred, crops are catching up.

Weed control is now vital if not already carried out. There is a range of quality products available and in good growing conditions, full rates of many herbicides can be reduced.

While some IPU products can now be used on spring barley I prefer the sulfonylurea product, Huzzar, for crops which have a tendency for annual meadow grass. However, this product can be hard on the crop.

If you use a hard water source, a softener should be added. The partner product for any sulfonylurea herbicide will depend on the likely weed spectrum that may be encountered.

It can include HBN (Stellox or Oxytril) for polygonums, or Galaxy for resistant weeds, like marigold and chickweed, and it is also very good on cleavers. These products will also help control weeds that have not been dealt with due to a failure to use suitable products in the past.

Fodder beet was also sown late but has made fantastic growth in the last two weeks.

The use of residual pre-emerge sprays at sowing time has worked extremely well.

Most crops are now ready for their T2, which should consist of a phenmedipham product such as Betanal or Wizard with metamitron (Goltix, Target, Glofo) added with a vegetable oil.

A graminicide, (Falcon, Fusilade Stratus, Aramo) must be used for wild oats or volunteer cereal control later.

Bean crops also look good this year and weed control is very satisfactory. However, graminicides may be required.

The main disease problem with this crop is chocolate spot and this will require a two-spray programme.

The first application should be at the first sign of infection, normally around the start of flowering. This can be Signum at 0.5kg or 0.5l of Amistar plus Folicur at 0.75l/ha.

Pat Minnock is a Carlow-based agricultural consultant and a member of the ACA and the ITCA.

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