Farm Ireland
Independent.ie

Wednesday 7 December 2016

Taking the best care of your crops from soil moisture to disease management

Gerry Bird

Published 10/05/2011 | 05:00

A large crowd take a walk on Teagasc's open day on the Greenfield Dairy Farm, Clara, Co Kilkenny. The main objective of this farm is to demonstrate best practice in the design, construction and operation of a low-cost, grass-based, large-scale milk production system within the constraints of commercial farm practice
A large crowd take a walk on Teagasc's open day on the Greenfield Dairy Farm, Clara, Co Kilkenny. The main objective of this farm is to demonstrate best practice in the design, construction and operation of a low-cost, grass-based, large-scale milk production system within the constraints of commercial farm practice

The past week has really demonstrated the impact soil type and structure has on crops. In the midlands and north-east, crops are showing various stress symptoms, all relating to the available soil moisture and nutrient uptake.

  • Go To

The winter crops on heavier soils, following break crops or organic manure applications are a good deep green colour.

By contrast cereals on sharper loam soils or poorly structured soils are lighter and variable in colour. The differences are mainly due to root mass and base fertility. I mentioned earlier in the season the importance of root development and this factor has really come into play now.

Fungicide

Disease levels in crops are generally low, and the bulk of the T1 fungicide applications have been carried out. The winter oilseed rape crops vary from full flower to 50pc petal drop. Normally at this time you will see petals stuck to leaves, providing a substrate for fungal growth and requiring immediate fungicide application.

The dry leaves and windy conditions have blown the leaves to the ground so the immediate threat is reduced.

It is good practice to apply a robust triazole fungicide now, despite the lack of disease to ensure the canopy remains clean.

Despite the excellent dry weather, spraying has been difficult, with high temperatures, strong sunlight and wind reducing the opportunity to spray.

Also Read


The condition of the crop is another factor to take into consideration -- I have noticed that crops are strongly waxed, particularly winter oats, which makes spray penetration difficult.

The crop leaves wax up in response to the climatic conditions, bright sunlight with warm windy conditions in low density crops maximises this effect. The crop leaves wax up to minimise water loss, so likewise it is difficult to get a spray solution in.

On a bright hot breezy day a fine spray solution on a leaf will evaporate and will not penetrate the leaf. Spray application is best carried out in the late afternoon and evening to maximise uptake.

The plant pores on the underside of the leaf open in the evening and at night and a medium spray quality applied at 2.5-3.0 bar pressure will drift the spray down through the crop, facilitating maximum uptake.

Spring barley crops are under pressure and many crops are redistributing nutrients from the older leaves to the newer ones, with yellow bottom leaves evident.

Trace element deficiencies are common place particularly manganese and zinc in my area, a case of a dry soil and poor moisture around the root zone reducing the possibility of uptake.

There are many examples of variable trace element uptake pattern, with good uptake on tyre wheelings and deficiencies on the loose soil.

Spring oilseed rape is struggling to emerge, and inevitably there will be a range of growth stages when the crop finally gets going. Weed competition could be a problem as redshank and fat-hen can get ahead of the rape particularly in darker damper soil, when rape emergence is variable.

Observing the quantity of fertiliser sitting on the ground, particularly on winter crops from the second nitrogen split, raises concerns about a sudden growth surge when the rain finally comes, especially in the north-east.

Growth

Winter barley is past the timing for growth regulator when the heads are out, wheat still has the flag leaf to come, with time to apply additional growth regulator.

I feel that wheat crops will extend and that the final internode will be long and possibly weak, particularly on tall, weak-strawed varieties such as JB Diego and Lion, so consider applying growth regulators such as Terpal, Moddus and Cerone, while noting the recommended timing (GS 39-49).

Finally, the Combines 4 Charity Open Farm at Rathfeigh is looking great, probably due to the excellent land, expert advice and skilled management!

It is a great show piece for the power of farming co-operation and dedication and the committee extends an open invitation to farmers to visit the site. Check out www.combines4charity.com for more details.

Gerry Bird is a crop consultant and member of the ITCA. Email: gjbird@eircom.net

Indo Farming