Farm Ireland

Wednesday 25 April 2018

Nitrate regulations or not, farmers work according to calendar year

Spraying may need to be carried out soon.
Spraying may need to be carried out soon.
PJ Phelan

PJ Phelan

Calendar farming has been a bone of contention with farmers since the advent of the nitrate regulations. But, the reality is that, when the crunch comes, farmers often work by the calendar anyway.

For example, this year many wheat growers have applied their T1 in the latter part of April without determining if the third leaf was fully out. They are now facing having to do a T1.5 in order to get to full flag leaf coverage before their T2.

The same farmers will probably spray three weeks after the T1, regardless of the crop growth stage. Second to timing is product choice. This is important, but is being restricted.

Growth stages (GS) in winter wheat currently range from 31 in late-sown, cold soils right up to 39 in some very early parts of the country. This is why some crops are still not due their T1, while others are due their T2.

Rotate epoxicolazole products with prothioconazole to reduce the risk of resistance build-up. Most programmes will include SDHI at T2. It is better to use higher rates of triazole than reduced rates of SDHI. Bravo should be included at both T1 and T2 and probably at T3.

However, omit Bravo if your timing is late as it reduces kickback. But don't be tempted to go too early with a spray because, if leaves emerge after spraying, they will be exposed to infection.

Most winter barleys have received their T2 and are relatively clean. SDHIs are strong on ramularia and are good for retaining green leaf. Bontima should perform well on clean crops. Use Siltra type products on crops with established rhyncosporium. It is preferable to include Bravo unless kickback is required.

Spring barley emerged very fast this year and plant stands range from good to excellent. With high soil temperatures and good growing conditions, crops will move through the growth stages quickly, but this can result in poor tillering.

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Growth regulators can be used to counteract this, but they must be applied before GS30. Late sowing and the mild winter will leave crops exposed to BYDV risk. Apply a pyrethroid at GS14. Inspect crops for aphids three to four days later and, if present, apply cloropyrifos or pirmicarb.

Slugs are a problem in spring sown crops after leys, grassy stubbles or where there was a high level of trash over winter. With Draza (methiocarb) due to be taken off the market in autumn, you should probably start alternative methaldehyde products to test their efficiency.

Leatherjackets are unlikely to be a major problem, but they can still be a risk in spring sown crops after first or second leys. They can be controlled with chloropyrifos, ideally just before rain to help incorporate it.

Weeds that spread on the soil surface such as chickweed, cleavers and redshank will significantly compromise the ability of your crop to tiller, so it is important to spray early.

Most herbicide programmes will include a sufonylurea and tank mix partner of mecoprop, HBN or fluroxypyr. HBN improves control of knotgrass, speedwells, deadnettles and pansy. Galaxy is for resistant chickweed and corn marigold.

This year, a new product, Pelican Delta, has been added to the armoury. It consists of diflufenican and metsulfuron and will control a wide range of broadleafed weeds and has some residual effect. It must be applied to moist soil.

However, it is poor on fat-hen and black-bindweed and is incompatible with chloropyrifos. Isoproturon based products are approved on spring wheat and barley and will control annual meadow grass if applied before the grass starts to tiller. Hussar is also very effective, but avoid applying to crops under stress.

You need to read pesticide labels carefully to ensure crop safety and compliance with regulations.

Be careful with tank mixes and, if you are growing crops under contract, check that products and tank mixes are within the specification.

Wash-out procedures after using chemicals should be adhered to carefully, particularly if moving to a crop that is sensitive to chemicals that have been in the tank recently.

Chemicals that have been allowed to dry onto tanks are difficult to clean and it may be the wetting agent in your next tank mix that will "clean" both your tank and your crop.

Finally, when receiving chemicals, check that everything on your invoice is in your delivery. Recently, one of my clients found that his delivery was short of 5l Amistar and 5l Proline, worth €500.

  • Patrick J Phelan is a member of ACA and ITCA

Indo Farming

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