This week, we continue with reports from the recent crop research and advice stands at the Crops and Spraying event in Teagasc Oak Park. The reports are provided by the advisers and researchers who manned the stands on the day and who spoke directly to growers.

Aphid control and BYDV

This was a very busy station given the amount of BYDV evident this year and the recent reports of aphid resistance in the pyrethroid insecticides.

Growers were concerned about the potential loss of effective aphid control if pyrethroids become less useful in the control of grain aphids.

The BYDV risk factors were explained in respect of early sowing of winter cereals, mild autumns and mild winters, late planting of spring cereals, aphid numbers and the presence of virus.

With early sowing being a big risk factor for winter cereals, options such as seed treatment followed by insecticides were discussed, as was the suggestion to delay planting where possible and practical.

With spring cereals, early drilling tends to reduce infection risk, which increases when planting from April onwards. But other issues, such as coastal infection pressure, and risk factors, such as recently ploughed-down green cover and uneven establishment, add to the risk of infection. Many growers suggested that variety appears to have an impact on the level of virus visible.

The topic of high aphid numbers feeding on cereals was also discussed. Action must be guided by numbers relative to timing, but one should never apply pyrethroids at this late timing. Growers were reminded that the cheaper systemics, such as dimethoate, cannot be used on barley or oats.

Many farmers present reported that they only include aphicide with the T3 fungicide on wheat if necessary. However, this was mainly reported by growers who had their own sprayers, while growers using contractors often included aphicide as a matter of course to help avoid an additional spray cost.

Most growers were aware that resistance in aphids to pyrethroid insecticides has been found in a few instances in Ireland. Further research is now being conducted to ascertain the extent of this resistance and to examine if aphids exist with more than partial resistance.

– Eamonn Lynch, Michael Gaffney and Lael Walsh

Beans research

Teagasc has recently initiated a major research programme on beans to improve husbandry information in light of the expanding acreage. The research is looking at a range of husbandry to provide an improved understanding of the basis of yield creation.

Husbandry trials are examining the relationship between variety, time of sowing (from late November to early April), seeding rate (15 to 60 seeds/m2) and the use of early nitrogen. Other trials are examining weed control options, disease control and the impact of growth regulators on flowering.

Another trial is examining the response to phosphate fertiliser applied on Index 1, 2 and 3 soils, with different rates tested as surface application, incorporated or placement drilled. Asked about the optimum number of fungicides for beans, the advice was that two treatments are regarded as the safest approach. So not opting for a two-spray approach is regarded as a big gamble.

The question was asked if we should be using higher seeding rates, given that the recommendation in the UK is for over 50 seeds/m2, as opposed to 35 to 40/m2 here. Crops can look better where plant population is higher, but this can also favour disease development and lodging in our climate.

There are a number of realistic options now available for crop establishment. Direct drills help to get the seeds planted deeper, thus helping to reduce crow damage. But we must still be mindful of soil conditions at sowing.

A research project to look at different establishment systems and row spacings will commence at the end of this year.

Fertilisation is equally important for beans as for other crops. One treatment had nitrogen applied at sowing, but this did not appear to benefit early season growth – harvest yield will tell.

A phosphorous application rate and method trial, on a low P index soil, turned a lot of heads. There was amazement at the differences in canopy size arising from the different treatments, but we must wait until harvest to see if this is translates into yield. Placed P could be even more beneficial when direct drilling into low P index soils.

The presence of black bean aphid infested plants prompted questions on the need to spray or not.

It was advised to use the threshold of 5% of plants infected before spraying. It is unusual to reach this level of infestation in a commercial crop, but infected plants can carry a huge number of aphids.

If you are spraying, remember the value of bees to this crop and use a bee-friendly insecticide or spray very late in the evening.

– John Carroll

Disease control in winter wheat

One of the main conversation points was how clean winter wheat looks this season.

Since 2012, wheat production has been in decline for various reasons, including the difficulties and cost of keeping crops clean from septoria. Wheat needs a good year and there is a quiet optimism that 2015 will help.

Growers queried as to why 2015 had such low septoria pressure and were surprised to see disease now appearing on the flag leaves of untreated plots.

Growers understand the issues relating to fungicide resistance and there is good awareness of the need to protect current chemistry. However, many expressed concerns regarding the ability of current chemistry to protect crops when spray intervals are stretched, especially between T1 and T2.

When we applied our T1 treatment, the third-last leaf was fully emerged (the correct timing). On that day, we also ran a paint aerosol across the plot to paint the leaf surface that was sprayed at that time.

This showed that this spray not only coated the third-last leaf, but also a large proportion of the second leaf. This visual display provided reassurance that the second-last leaf was not left exposed and that an additional application to protect it was not required. But when the T1 is applied too early, programmes will be out of sync.

No two seasons are the same and spray intervals will get stretched in some seasons and be shortened in others by rapid growth. That said, the main factor in spray timing should be leaf emergence and not number of days between treatments.

While fungicides remain essential, there was general agreement of the importance of varieties with good disease resistance. All elements of production – variety, sowing date and an understanding of disease development – need to be considered.

– Steven Kildea

Spring barley disease control

The gap between T1 and T2 on spring barley was also very topical.

The message on this one was to again target the growth stage rather than the spray interval.

Growers were anxious about spraying at mid- to late-tillering where disease pressure was not high.

A key message was not to delay the mid-tillering spray and to apply the second fungicide as the awns emerge.

It was also recommended to split the spend equally between the first and second spray due to the importance of the T1 on spring barley.

Yield potential is established at the beginning and cannot be improved or increased later on. It’s about protecting the potential that is there.

A minimum of two actives must be used at each application to help protect Proline.

– Liz Glynn

Oats

The presence of a big oat research programme was welcomed. This is an important crop for many growers and there has been little or no relevant research in recent decades.

Grower questions related to nitrogen rates, growth regulator timings and products, availability of new varieties and spring versus winter planting for cost saving.

The answers to these questions are currently a matter of opinion or regulation, as there has been no recent research to guide this advice. The aim of the research is to help give better guidance on all these issues.

– John Finnan, Larry Murphy

Cover/catch crops

The range of cover crops generated considerable interest, especially from growers considering this option within GLAS or as ecological focus area (EFA). Many growers were only seeing some of these crops for the first time.

The most common question was “what is the best choice of crop?” This was followed closely by “how should I sow it?”

There is no single answer to these questions, as the choice of cover crops will depend on the rotation, whether or not you want to graze post-December, what benefits you want to target from cover crops and how you propose to sow it.

For growers with principally a cereal rotation who wanted to get some grazing after the GLAS 1 December retention period, a mixture containing forage rape, oats and leafy turnip or radish was suggested. For those wishing to incorporate the crop to help improve their soil, the use of tillage radish, oats, mustard and vetch was recommended.

The impact of these crops on the farm rotation was questioned by many farmers who had beet, beans, oilseed rape or oats in their existing rotation.

These different crops all bring their individual concerns with regard to sclerotinia, club root, crown rust and oat mosaic virus, as well as volunteer regrowth and providing a green bridge for pests.

A key message was to avoid excessive cost as, other than the GLAS payment and any grazing value, the economic benefits of using catch crops are variable and often small.

Many growers were unaware that a cover crop would only qualify for payment under GLAS if the grower had been officially accepted into the scheme.

The importance of having good seedbeds to enable establishment of these small seeds was emphasised.

– Richie Hackett, Phelim McDonald

Looking at GLAS

The GLAS stand covered a wide range of aspects for the tillage farmer. It featured options such as catch crops, arable margins, environmental fallow, wild bird cover, hedgerows, traditional orchards, native woodland planting, boxes for bird, bats and bees and habitats.

Tillage farmers were mainly interested in the catch crop and wild bird cover options. The main catch crops question related to the most suitable crops to sow in a rotational situation. The advice was to steer clear of all the brassicas where oilseed rape is grown in order to avoid undue disease risk.

Farmers were also interested in the use of catch crops for soil fertility improvement.

The advice given was to consider legumes where practical (again, there are disease risks if a legume is included in the crop rotation) and that the main options were vetch, clover, peas or beans.

There was also considerable interest in the choice of catch crops for subsequent grazing. The catch crop can be grazed after 1 December each year. The advice given was that a mix of leafy turnip or forage rape would give the best value for grazing animals. But the full crop rotation must be considered.

There was also good interest in the wild bird cover for GLAS. Farmers asked about a mix that had to be planted every year or one which includes kale, which is a biennial plant and only needs to be planted every second year.

This generated some confusion because even where the kale does survive, there is still an obligation to plant the partner crop(s) like cereals every year.

The other mixes allowed under GLAS include oats or triticale along with any one of either linseed, mustard or oilseed rape and these need to be sown annually.

This stand also featured a demonstration of best practice for planting a whitethorn hedge. It is recommended to put a strip of plastic on the ground to help prevent weed competition.

Where plastic is used, the new whitethorn whips should be cut back to approximately 6” from the ground to encourage the plant to branch in order to produce a dense, stock-proof hedge in time.

However, cutting back is not recommended if plastic is not used, as weeds and grasses are likely to smother the hedging plants.

– Marianne Mulhall

AMIGA potato project

Interest continues in the GM potato blight research project at Oak Park.

Many suggested that the public dissemination of the results generated should continue even after the project ends. This is important to help ensure that the general public remains aware of the challenges facing crops and that these new technologies could provide potential solutions.

In general, farmers were aware of the research and many wanted to understand the technical aspects of how the blight resistance was inserted. Growers asked about the robustness of the genetic resistance inserted and the likelihood that it could break down.

There was considerable interest as to the potential of this technology to provide septoria resistance in wheat or virus protection in barley.

– Ewen Mullins

Valuing varieties

A research project known as CIVYL has just commenced and its objective is to evaluate and quantify the benefits of the different cost or value features of individual varieties.

Studies will evaluate whether variety characteristics, such as disease susceptibility or lodging resistance, in winter wheat and spring barley can be a factor in targeting an optimum rate for inputs such as fungicide, nitrogen or growth regulator.

There were mixed views from growers regarding the potential benefits. Some believed that the ideal rate would be influenced much more by site and season rather than by variety.

However, others acknowledged that variety choice may need to have a greater role in future.

Either way, these studies will go a long way to providing a clearer view of the opportunities presented for producers by variety choice.

– Joe Lynch