The main influence on barley grain size and specific weight is the length of the grain filling period – the longer it is, the larger the size will be. The husbandry factor, drilling date, has the single most important influence with delays leading to very poor crop development that impinges on the grain quality.
Improving thousand grain weight in barley
It is important to determine Thousand Grain Weight (TGW) in Barley to enable an accurate control of the seed when sowing to obtain the correct plant population target.
Nitrogen and Sulphur
Nitrogen and sulphur will often increase barley grain yield through increasing barley grain number. This can sometimes be at the expense of grain size, instead producing more, smaller grains. If grain size is key, as is the case in some malting barley crops, then it is important to avoid excess nitrogen.
It should be noted that for yield attainment, grain number is more important than grain weight so care should be taken not to reduce it too much by focusing on grain weight. Small grains can also be caused through delayed or late applications of nitrogen that causes secondary tiller growth to form ears and grains. These late ears will reduce the quality of the sample being small and high in moisture content. If a crop lodges through either excess nitrogen applications or potassium deficiency this will curtail the final grain filling period giving small, unripe grains.
Copper, Manganese and Boron
Research has demonstrated that the micronutrients Zinc, Copper, Manganese and Boron have all increased the Thousand Grain Weight (TGW) in barley .
