Barley leaf pores point to higher yields, Estonian study finds
Friday 30th October 2026 on 09:49 in
Estonia
Summer barley plants with more open, higher-conductance pores on the upper side of their penultimate leaf produced higher yields, an Estonian study has found, ERR reports. The finding could help breeders develop barley varieties that are more drought-resistant and productive.
Researchers from the University of Tartu Institute of Technology and the Estonian Centre for Rural Research examined leaf pore traits and their relationship to grain yield in 13 barley varieties from 2022 to 2024.
How leaf pores affect plants
Stomata are openings in the leaf surface, formed by two guard cells and a gap between them. They allow plants to absorb carbon dioxide for photosynthesis and release water vapour. In cereal crops, stomata are distributed relatively evenly across the upper and lower leaf surfaces.
The researchers measured stomatal conductance on the penultimate leaf and the final leaf, known as the flag leaf. They also examined stomatal density, distribution between the two leaf surfaces and the length of the guard cells.
Stomatal conductance indicates how much water a leaf loses through its pores over time. Plants can adjust water loss within minutes by opening or closing them. Other traits, including stomatal density and guard cell length, are shaped over a longer period as new leaves develop.
Yields varied by year
The field trial at the Estonian Centre for Rural Research fields in Jõgeva recorded grain yields ranging from 2,400 to 6,100 kilograms per hectare. The varieties’ average yield in favourable 2022 was twice as high as in 2023, which was an unfavourable year.
Yields were also relatively low in 2024. Low rainfall and above-average temperatures in May and June in both 2023 and 2024 were cited as possible reasons. Although yields fell for all varieties in the poorer years, Allianz and Tuuli were among the higher-yielding varieties on average, while Tipo was among the lower-yielding ones.
Barley is the world’s fourth most important cereal and is widely grown in Estonia, where only wheat has a larger growing area and higher yields. The article notes that barley has received less research attention than wheat: a Web of Science database search found 75,000 wheat research articles and 13,000 on barley published over the previous five years.