Barley straw yields not a tall story, indicate trials
An independently-managed farm trial of spring barley has once again shown that a taller variety doesn't always result in the highest yield of straw.
Organised by Scottish Agronomy at Newbigging in Angus, with support from Syngenta Seeds last year, the trial, which was managed under the farmer's own input regimes, was designed to compare grain and straw outputs from three different spring barley varieties, each with different straw heights on the HGCA Recommended List 2008 – Waggon, Doyen and Riviera.
Despite Waggon having the middle straw height figure of the three on the HGCA Recommended List, results from the farm trial indicated it produced 0.63 and 0.44 t/ha more straw respectively than the other two varieties – this was based on number of bales produced from a measured area, and with an assumed normal weight of 200 kg per bale.
Additionally, estimated yields from the combine yield meter in the trial indicated Waggon to produce 7.4 t/ha of grain versus 6.8 t/ha from the other two.
Based on prices for feed barley of £145/t for grain and £40/t for straw, the total value of this extra straw output from Waggon could be worth between £17 to £25/ha, calculations by Syngenta Seeds indicate, while the value of its extra grain output could add a further £87/ha.
Moreover, findings from this 2007 trial support those of similar studies over the last two years, says Robert Hiles of Syngenta Seeds, in which Waggon repeatedly produced high straw and grain yields.
Commenting on the findings, Andrew Gilchrist, managing director of Scottish Agronomy noted: "Yet again, our spring barley trials have shown that tall barley varieties are not necessarily the best crops for producing high straw yields.
"Straw yield is not necessarily linked to straw length, but the tillering ability of the variety.
"In simple terms, if a variety producing 1,000 fertile tillers per metre squared is compared to a variety which produces 750 tillers per metre squared, and both varieties are of equal height, then the high tillering variety will produce more straw yield. Some of the tall feed types have a shy tillering habit and therefore do not produce large straw yields, despite their height.
"We endorse Waggon simply because of the combination of yield – grain and straw – stiffness, and disease resistance," he added.
Also, he notes that some of the attraction of tall feed types is related to their perceived 'combine-ability'.
"A significant proportion of feed varieties are grown in small, mainly livestock dominated units. These units tend to have older combines, or use neighbours to harvest for them. A significant area of this feed barley will not have been rolled.
"They therefore tend to cut the barley to leave a longer stubble, to avoid damaging the combine, which may have to last many more years than on a large arable unit. They therefore perceive the 'tallness' as an advantage. It is probably the case, however, that they will still get a higher straw yield from Waggon – and grain yield – if they cut it slightly higher than the norm."
