Over the last ten years we have been seeing an increase in yield of 1% per year as new spring barley varieties come to market, which is substantial, and an increment in yields that we are just not getting in other arable crops, says Ron Granger, technical manager.
“New malting varieties now have equal or better yield potential than standard feed varieties, thanks to breeders influence on germplasm.”
“Back in 2009, Concerto set an exciting benchmark for distilling varieties for quality and yield, however new varieties sitting at the top of the 2018 AHDB Recommended List boast yields that are 10%+ higher yielding than Concerto.”
“LG Diablo is currently the highest yielding spring barley variety ever, promising yields of 106% over control nationally, next down LG Tomahawk’s yields are 105% over control – this is way above those of Concerto at 94%.”
LG Diablo
Having just been through one of the most challenging seasons for spring barley yields, recognising how we grow the crop to achieve high yields and meet contractual specifications of the chosen end market is crucial to success, he says.
“Spring drilling for any crop is about patience and making the decision to drill at the right time when conditions allow for good germination and continuous plant growth.”
“However aiming for the right drilling rate in ideal conditions is always a challenge in the topsy turvey weather of the spring; never has this been more evident than last spring when the conditions never really improved and delayed drilling was inevitable!”
“Growers that were able to get crops in the ground with good seedbed conditions and moisture had good yields, but unfortunately not all growers had this opportunity and were made to drill later as they could not travel on the land!”
“Where crops were drilled later, seed bed conditions were not ideal, and more importantly soils were losing moisture and resulted in slow germination and crop establishment, which impacted yields as we know. “
So what have we leant from 2018 that we can take through to the next season?
Seed rates
“We continue to invest in trials, both internally and externally, to fully evaluate the agronomic requirements of the spring barley crop and the subtle differences between varieties.”
“This allows us to give growers the best advice to ensure that both high yield and end-use specifications are met as closely as possible.”
Limagrain do not advise definitive seed rates for spring barley but suggest suitable seeding rates, based on the knowledge of the variety gained through these plot and field trials.
“For example, in our trials carried out over several years looking at both drilling date and sowing rates across Scotland and the rest of the UK to determine optimum seed rate figures, we found that a starting point of 350 seeds/m2 appears to be the optimum for most varieties in ideal growing conditions.”
“This figure can then be either decreased or increased depending on the conditions and time of drilling.”
“This is because spring barley sown in February or March has the opportunity to tiller but the later the drilling date, seed rates have to be adjusted upwards to account for the lack of tillering ability, to ensure final ear counts are achieved for ensuring final yield potential.”
“This spring the later sowings needed higher iseed rates to ensure final ear numbers were achieved from the final plant count for ensuring final yield potential,” he says.
Tiller Counts
The target final tiller number for spring barley in the AHDB Barley Growth Guide is 775/m2 (3 shoots /plant), and looking at both trials and farm plant populations over the last few years, this appears to be underachieved in many situations – therefore compromising yield, says Mr Granger.
“Work that we have been carrying out in Scotland that involves recording tiller counts shows that the varieties such as Sienna and the candidates LG Diablo and LG Tomahawk produce higher tiller counts, which correlates into increased yield.”
“It’s important to recognize that varieties with higher tiller counts also show benefits in situations of stress, i.e. drought, showing that they will compensate where plant numbers are low, whereas low tillering varieties are limited in their capacity to compensate.”
LG Tomahawk
He points out that Limagrain trials have shown that final tiller counts can be pushed over 1000/m2 in very fertile soil conditions, but there does not appear to be any additional yield performance over the 750/m2 final tiller target.
“In fact, it can lead to negative agronomic traits being induced, such as lower specific weights, higher screenings, additional lodging pressure and increased disease pressure.”
Nitrogen interaction
The conventional approach to the spring barley fertiliser regime needs to be investigated, to see if additional yield performance can be obtained with higher rates of nitrogen, suggests Mr Granger.
“This is not straight forward as the final grain nitrogen percentage cannot be compromised, especially if growing for the malt distilling market which requires a low grain nitrogen content.”
“However, higher grain nitrogen levels required by the brewing and grain distilling contracts should offer opportunities for driving for additional yield potential with higher rates of nitrogen, while still achieving the specific grain nitrogen percentage.”
In our trials work, in conjunction with Scottish Agronomy, looking at variety interaction with differing nitrogen rates over a range of Limagrain varieties, we applied 120 kg/ha N in the seed bed, supported by an additional 30 kg applied at tillering, making a total input of 150 kg/ha.
“The result was an additional 0.4 – 0.5 t/ha yield across the varieties.”
Whilst this is significant certainly in a commercial situation, it has to be compared with the actual grain nitrogen percentage figures, he continues.
“The grain nitrogen percentage did not increase significantly, remaining well within the contract specification of below 1.65% grain nitrogen for malt distilling contracts. One could argue that the additional yield had a dilution effect on the final grain nitrogen percentage as anticipated. “
“We should also take into account that some seasons produce lower grain nitrogen accumulation levels, highlighting the importance of continuing trials over several seasons.”
Pushing spring barley yields
- Higher tillering varieties should be considered in a black grass situation.
- A higher nitrogen rate with an additional 30 kg/ha at growth stage 12-20 gave a yield increase across all seed rates. Grain nitrogen percentage was not compromised in this specific trial, ongoing trials evaluation to be continued.
- Additional nitrogen to the lower tillering varieties i.e. Concerto at the lower seed rate (250 seeds/m2) increased both tiller numbers and final yield significantly.
- Higher yielding varieties such as Sienna LG Diablo and LG Tomahawk are able to compensate for low seed rates and plant establishment, because of increased tillering capabilities.