Targeting top spring barley yields

This week’s report from the Teagasc Tillage Conference looks at the recipe for high yield potential in spring barley – 350 seeds/m2 to give around 1,000 ears/m2.

Little things make the difference and that was mainly what helped the tillage BETTER farms produce higher profits than equivalent farms in the national farm survey in recent years.

Despite the low disease pressure in 2013, septoria continues to slip from the eradicant control capability of triazole fungicides.

Making barley yield

Four years ago, Shane Kennedy began researching yield variability in spring barley and asked if yield could be pushed further through higher seed numbers per unit area. This research showed that spring barley (variety Quench) needs to have around 1,000 ears/m2 to produce its optimum yield level.

This ear density is best produced from around 250 to 270 plants/m2 with an average of three tillers per plant, plus the main stem. These were the simple conclusions of Shane’s work over three years in which he generated a range of ear densities from hugely varying plant populations.

This ear density has long been associated with the optimum yield level in modern spring barley varieties. However, in this series of experiments, Shane posed the question as to whether higher ear densities could produce higher yield. While he produced higher ear densities, yield tended to level off as higher numbers of ears tended to have smaller ear size and the combined ear number and ear size tended to produce the maximum number of grains per unit area at around 15,000 to 20,000 grains/m2, depending on the season.

In the three years of trials, average grain yield varied from 7.5t/ha in 2013 to 9.9t/ha in 2011. The biggest grain size was achieved in 2013 but that year had the lowest grain number per square metre and the lowest average grain yield. Shane pointed out that this was largely due to poor establishment at the Carlow site following early drilling and these plots just did not compensate adequately.

Ear counts below 1,000 were generally not able to fully compensate, with even bigger ears, and this generally resulted in fewer grains and a lower grain yield. In situations where the plant count fell well below 250, Shane said that the use of growth regulators early did not tend to enhance tiller number.

However, he also said that the use of growth regulators, which had the potential to suppress apical dominance, tended to enhance tiller survival and that this may be a better way to increase final tiller number and ear count. Care is needed here because treatments which manage to push ear count well above 1,000/m2 could increase the risk of lodging and this would be critical, especially in malting barley.

In this trial series, Shane covered some plots with a shading canopy around the end of June to see if the shading effect would result in the loss of grains or tillers. The results showed no major consequence. This was because the high level of stem reserves helped feed the plants and keep them going when sunlight was restricted.

At the Cork site in 2012, the absence of stem reserves due to poor spring growth meant that the dull summer affected final grain yields at that site.

BETTER profit levels

The current tillage BETTER Farm programme has concluded. Michael Hennessy of Teagasc summarised the performance of the programme by stating that the sum of the small changes implemented during the programme helped to put the financial performance on these farms above their equivalent counterparts involved in the National Farm Survey (NFS).

Many tillage farmers visited the BETTER Farms in Cork, Meath and Wexford during the open days in recent years. The changes were generally subtle and largely unnoticed. They involved a broader cropping programme than had existed previously and this helped workload and profit.

What was most noticeable from the results presented was the consistently higher level of “common profit” produced on average on the BETTER farms relative to their NFS counterparts, even in 2012.

Crop yields were not always higher than the NFS equivalents but they were never poorer and that, coupled with improved focusing on costs, helped produce higher profit margins which is what farming is about.

As well as the farm performance, these farms also provided the vehicle for a range of focused trials to help support farm yields.

The most publicised of these was the fertility work done on the placement of phosphorous for spring cereals. The famous early spring photographs, which showed the dramatic improvement in early spring growth, caused a rethink on the benefits of this forgotten or ignored husbandry practice at farm level.

The result has been a major interest in combine drilling, especially on land that is low in soil phosphorous. This is especially important for growers farming worn conacre where soil index P levels are frequently low.

The research also showed that no amount of additional top-dressed P could compensate for the relatively little applied down the spout where it was most needed.

This work also showed no benefit in combine drilling P for winter wheat but the same may not apply for winter barley and the practice now needs to be checked on this crop.

Another important outcome was the identification of inadequate K as a yield constraint in cereal production on these farms. Improved crop nutrition was seen as one of the major reasons for the improved performance on these farms over the course of the programme.

Michael also said that the BETTER Farm programme had resulted in an improved machinery cost calculator and had driven the development of Teagasc’s share farming initiative. These things combined to help change the cropping programmes on farms to help make better use of the machine capacity available.

Another point worth noting from this work is the value of having advice on hand at all times. The nature of tillage farming is that there is very little time to make decisions and get the work done. This was a significant factor in the delivery of the good financial performance on these farms over the duration of the programme.

A new programme of BETTER Farms is about to start. This was reported last week when Dermot Forristal told us that this programme would involve work on precision farming. But Michael stated that it will continue to concentrate on husbandry, management and research action also.

So Teagasc now requires new participating farmers for this new programme.

Fungicide slippage again

A good year for disease on farms means low natural pressure and low disease levels but this is a bad year for fungicide trials. That was how Teagasc’s Steven Kildea opened his presentation on the performance of fungicides and the development of disease in 2013.

However, last year was not without its milestones and while control of the main diseases proved relatively easily, this did not seem to stop the march of reduced sensitivity in septoria to the triazole actives.

One of the first slides that Steven presented appeared to show a significant further decrease in the sensitivity of septoria to epoxiconazole. But Steven stated that this is not a new population but a substantial increase in the prevalence of less sensitive types that have existed in previous years.

This same finding has resulted in a significant decrease in sensitivity to epoxiconazole within populations in parts of the country that were sensitive one year earlier.

While there were places in Munster, the Midlands and the southeast where epoxiconazole might have done well on its own against septoria a year earlier, the 2013 monitoring shows that these have now all become quite insensitive to epoxiconazole.

Perhaps an even bigger worry can be found in the monitoring of populations for the combined insensitivity to both epoxiconazole and tebuconazole. These two actives represent different “families of insensitivity” and in the past populations that had become less sensitive to one were susceptible to the other. While a small number of insensitive types to both triazole families were found two years ago, these have become much more prominent.

There must be a real concern about our ability to control both of these insensitivity families with our dual actives, eg epoxiconazole plus metconazole or prothioconazole plus tebuconazole. While this insensitivity work does not necessarily indicate control failure at field level, the shift towards these double insensitivity types looks ominous for control difficulties.

Teagasc work on “pushing sensitivity” has shown that certain actions can help slow the development of insensitivity at field level. Monitoring has shown that the inclusion of a contact fungicide with a single triazole can considerably slow the appearance of insensitive types in a field population.

Trials also showed that less insensitivity developed where somewhat more sensitive actives like metconazole (Caramba) were used. Also, epoxiconazole followed by Caramba showed more end-of-season sensitivity than Caramba followed by epoxiconazole.

Monitoring of septoria sensitivity to the SDHIs also continues but, thankfully, no problems can be reported for the moment. And the same can be said for net blotch with regard to the SDHIs but such problems have been found in other parts of Europe.

Steven also reported that no further problems have been found with regard to strobilurin resistance in net blotch.

Teagasc is looking to select new farms for the next BETTER Farm crops programme following the successful completion of the first phase of the project. The BETTER Farm initiative aims to demonstrate best practice and to introduce new technologies to farmers.

The next phase will focus on two key objectives:

The Teagasc team, led by Michael Hennessy and Dermot Forristal, will work with the selected farmers to identify options to improve profitability throughout this period.

The Precision Agriculture element is a new component which seeks to assess and demonstrate a more precise response to crop management. This will include the measurement of variability using yield, soil quality and satellite mapping technologies, where available. Field trials and sensing technologies will be used to help counteract the variability.

The new BETTER farms will be selected based on region, soils, crop mix and the availability of good physical and financial records. An interest in adopting precision farming is a further key requirement this time. Growers who have some precision agriculture capability would be of particular value to the project but this is not essential.

While the major focus will probably be on three main farms, other farms could also be involved so if you are interested, go for it.

While the main aim of the BETTER Farm initiative is technology transfer, the agronomy and financial management packages, plus the opportunity to have trials conducted on one’s own land, are key benefits for participants.

If you are interested in participating as a BETTER Farm, contact Michael Hennessey (059 9170200 or email michael.hennessy@teagasc.ie) or your local tillage adviser before the end of February.