Abstract
Specific weight (SW) is a long-established measure used as a malting quality specification in barley, with an increased SW thought to result in a higher malt output. Specific weight is a product of individual grain density as determined by grain composition and structure, and grain packing efficiency in a container as determined by grain dimensions. We investigated the effect of moderate but prolonged post-anthesis water stress on barley plant and grain development using pots of cultivars with a known range of SWs to explore how altering plant growth influence SW. Water stress was expected to influence these grain characteristics through decreased photosynthetic capacity. We demonstrated that SW was maintained under water stress conditions through compensatory mechanisms such as increased tiller mortality which preserved grain physical parameters on the main shoots. However, water stress significantly affected plant development by reducing not only ear number and yield, but also grain filling duration, plant biomass and ear length. Grain composition was also altered, with water-stressed plants having reduced carbon:nitrogen. Therefore, although SW can be conserved under water-stressed conditions, grain composition and plant development are altered, producing smaller harvests with higher grain nitrogen content. This would result in bulks of malting barley having different malt outputs despite having the same SW.
Highlights
Barley (Hordeum vulgare L.) is an important cereal crop worldwide
Stress and and Plant demonstrated that thatthe thewater waterstress stresstreatment treatment resulted a quickening in SPAD readings readings demonstrated resulted in ainquickening in leaf leaf senescence, indicating the water stress treatment successfully reduced the total duration of senescence, indicating the water stress treatment successfully reduced the total duration of photosynthesis plants
Specific weight was maintained under water-stressed conditions; many aspects of plant development were altered by the water stress
Summary
In 2017 a total of 147 million tonnes were harvested globally and in the UK 7 million tonnes were harvested from 1.2 million hectares [1] The majority of this is grown for feed and malting. In the UK, it is largely spring barley that is grown for malting, and it is required to attain certain grain quality specifications and if these are achieved a premium is paid compared with barley destined for feed. One of these quality specifications is specific weight (SW), a measure of the weight of grain per unit volume, and is measured in kilograms per hectolitre (kg hL−1 ). Minimum SWs are specified in a contract between farmers and end users
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have