Tillage Update - 20th August

Ciaran Collins, Teagasc Tillage Specialist gives an update on the harvest, particularly in areas affected by rain and drought and an overview of winter oilseed rape & selecting varieties from the DAFM's recommended list. Listen to this week's The Tillage Edge focusing on desiccating potato crops.

Harvest update

Rain has once again stopped harvesting in this stop start harvest. Winter barley and winter oilseed raped are finished and growers have made a start on spring barley and winter wheat. Grain quality is excellent to date but yields are variable depending on how affected crops were by the drought in April and May.

In drought affected areas some crops of winter barley struggled to surpass 7.5t/ha whereas yields in excess of 10t/ha were achieved in southern areas, mainly from six row varieties. Winter wheat and spring barley are following a similar trend where with better yields coming from land further south where the effect of the drought were least evident in April and May.

Specific weights in cereals are excellent to date, oats in the mid to high 50’s, barley in the high 60’s and some wheat reaching 80 kph. Green grains in the sample has resulted in some higher moistures but has caused some rejections for malting barley growers. Grain skinning is also an issue for malting barley growers this year, first time since 2016, and resulting in failures at the malting intakes. The recent humid weather has led to sprouting in some susceptible wheat varieties like Bennington and hopefully storm Ellen won’t be as bad as forecasted!

Winter Oilseed Rape

Winter oilseed rape has been the success story of this harvest with many growers achieving 4.5- 5.0t/ha at good moistures. Good rotations are essential for achieving high yielding profitable crops on tillage farms and winter oilseed rape is an excellent break crop.

Teagasc trials have shown that yield increases of up to 1.5t/ha are achievable after break crops in our most profitable cereal, winter wheat, when compared to continuous winter wheat. A good break crop like winter oilseed rape also has the effect of reducing input costs in the succeeding crops in addition to creating an alternative pathway for controlling difficult grass weeds.

The sowing window is from now to the end of August (early September in the South). Good establishment is critical for high yields and helps the crop withstand pest (slug/pigeon) attack and weed competition.

Teagasc establishment trials on winter oilseed rape has shown that;

• Plough-based, min-till and strip-till (including sub-soiler leg type) systems were all capable of achieving high yields.
• Row widths up to 500mm or 600mm did not hinder yield potential in most of the trials but it may be sensible to increase seeding rate by 10 to 15% when using strip till systems in wide rows.

Varieties should be selected from the Department of Agriculture, Food and Marine (DAFM) recommended list. Varieties on the DAFM recommended list have been grown in Irish conditions for at least three years so growers can be confident that these varieties are reliable. Sowing rate depends on soil conditions but usually in the range of 50 – 80 seeds/m², with conventional varieties at the higher end.

There are pre and post emergence weed control options. Herbicide choice depends on expected weeds but crucially winter oilseed rape provides opportunities to control difficult grass weeds. It is important to apply pre em herbicides before seed chits and do not apply if heavy rain is forecast.  

Winter oilseed rape is more profitable than spring feed barley in the Teagasc Crops Costs and Returns when target yields are achieved notwithstanding the additional yield from the succeeding crops.   Oilseed rape also provides an ideal opportunity to forward sell a portion of the harvest at sowing as most buyers will offer contracts and the price in recent years has remained consistent and less variable than cereals.

Desiccating potato crops

In this week’s podcast Ciaran Collins chats to Shay Phelan, Teagasc Potato Specialist, about desiccating potato crops. Firstly Shay gives an update on how crops are progressing as we approach harvest. He then highlights that there are significant challenges facing growers this year with, high disease pressure, deteriorating ground conditions and limited options making desiccating crops more difficult. For many growers this will be the first year that they will try to desiccate a crop without the use of diquat so Shay discusses the alternative approaches and outlines strategies that growers should consider this season and into the future.