Combines harvest grain by cutting the crop, threshing or loosening the grain and separating the grain from other plant components. But grain can be damaged in this process and rendered less suitable for specific uses or markets. Getting the combine adjusted correctly can help minimise the risk of damage.
Damaged grain, such as broken kernels and skinning (husk partially removed), can have a reduced value particularly for markets where the grain must germinate, such as for seed or malting. The grain’s germinative capacity can be affected by direct damage or growth of spoilage organisms.
The malting industry is particularly concerned about grain damage. The risk of damage can be reduced by setting and operating the combine correctly. There can often be a conflict between avoiding damage, producing well-threshed grain (no awns) and avoiding excessive grain losses from the combine. Frequently a careful balance is required. The following key points are worth considering.
Combines differ in their setting and adjustments: Differences in combine design between makes and models can result in different approaches to settings to avoid damage. For example, different threshing drum diameters result in quite different peripheral speeds for a given rotational speed (rpm on the in-cab dial). The layout of the threshing components varies with some manufacturers having rotating threshing elements before the threshing drum (eg Claas APS), while others have additional separating cylinders after the drum (eg New Holland RS and others). And of course there are many hybrid machines on the market with rotors replacing straw walkers allowing more separation to take place after the main threshing drum.Instruction book: Always consult the instruction book or, with advanced in-cab electronic systems, the default crop settings as a starting point for setting up the combine for individual crop types. These give a guide as to what approach to take to either reduce grain damage or increase threshing efficiency.Watch for wear: Significant wear in key threshing components (cylinder, concave etc) can result in more grain damage as the operator tries to correct resulting losses by increasing drum speed or reducing concave clearance. Also, check the basic setting of the concave ensuring parallel clearance across the drum width and the correct front to back clearance.Setting up: Setting the combine to separate the awn from the grain, while minimising grain damage, can be a particular challenge. Adding de-awner plates is recommended with some machines but this can reduce threshing capacity and careful adjustment is required to prevent grain damage.Drum settings: Cylinder (drum) speed and concave clearance play a huge role in threshing and grain damage. Slower drum speeds and wider concave will reduce grain damage, so start at this most gentle end of the scale, slowly increasing drum speed and reducing concave clearance to improve threshing. Always change one setting at a time and check for losses and damage and record your adjustment.Loading: Keeping the threshing element properly loaded is important. If throughput is reduced because of slow speed, grain damage can increase. This is because there may not be sufficient cushioning from the correct volume of material going through the drum.Sieves: Sieve settings are also important as the volume of grain going through the returns system for re-threshing should be kept low to reduce grain damage in re-threshing.Grain augers and elevators: Chains and flights on elevators should be correctly adjusted and free from excessive wear. Unloading augers should be engaged gently and disengaged as soon as the grain flow dwindles, as partly full augers are more likely to damage grain.Mature grain: With barley, removing the awns can be quite difficult, particularly if the grain is just ripe. More severe threshing with faster cylinder speeds and tighter concave clearances is used to try and remove the awn. This can increase damage. It can often be wise to wait a day or two as the awn will come off more easily with less aggressive settings and less risk of grain damage. However, this is difficult to do when moisture is low, harvesting weather is good and the risk of brackling is real. When the awns are left attached, this will result in a reduced specific weight (KPH), which could also lead to the sample being rejected in some markets. Remember, the exact approach to be taken depends on the combine model and you should always be guided by the manufacturer’s information, where provided. But that may only be the starting point – adjust carefully in a methodical way and assess grain damage, threshing and combine losses until the correct balance is achieved.
The issue of grain skinning has again raised its head at the start of the 2016 malting barley harvest. In this article, Teagasc’s Dermot Forristal gives guidance on combine settings to help reduce this element of the problem but skinning is likely to be more complex than just a combine setting issue.
Where has the problem come from? Has it been there all the time and are we only seeing it now because it is a rejection issue? There is little doubt that it is a real issue when a malting premium is at stake, but is it of massive consequence to either malting or brewing? While acknowledging the great work being done by our malting industry, growers and others rightly ask to what degree specifications can continue to be tightened in a product that is subject to the annual vagaries of nature and weather.
Are the skinning (and KPH) cut-off criteria set by the malting barley assemblers justifiable? How much is malting efficiency affected by these levels of skinning? If the effect on malt yield is modest, and the occurrence of skinning is varietal or season-dependent, are assemblers shooting themselves in the foot by exacting such standards? Acknowledging the need for concern, one must wonder why this appears to be an increasing issue?
Are we seeing variety weaknesses? Could this be a problem that is being bred into varieties as other malting quality criteria are edged up or down? While maturity and combine settings have a part to play, the industry must avoid varieties with such quality weaknesses. Livelihoods are at stake.
Combines harvest grain by cutting the crop, threshing or loosening the grain and separating the grain from other plant components. But grain can be damaged in this process and rendered less suitable for specific uses or markets. Getting the combine adjusted correctly can help minimise the risk of damage.
Damaged grain, such as broken kernels and skinning (husk partially removed), can have a reduced value particularly for markets where the grain must germinate, such as for seed or malting. The grain’s germinative capacity can be affected by direct damage or growth of spoilage organisms.
The malting industry is particularly concerned about grain damage. The risk of damage can be reduced by setting and operating the combine correctly. There can often be a conflict between avoiding damage, producing well-threshed grain (no awns) and avoiding excessive grain losses from the combine. Frequently a careful balance is required. The following key points are worth considering.
Combines differ in their setting and adjustments: Differences in combine design between makes and models can result in different approaches to settings to avoid damage. For example, different threshing drum diameters result in quite different peripheral speeds for a given rotational speed (rpm on the in-cab dial). The layout of the threshing components varies with some manufacturers having rotating threshing elements before the threshing drum (eg Claas APS), while others have additional separating cylinders after the drum (eg New Holland RS and others). And of course there are many hybrid machines on the market with rotors replacing straw walkers allowing more separation to take place after the main threshing drum.Instruction book: Always consult the instruction book or, with advanced in-cab electronic systems, the default crop settings as a starting point for setting up the combine for individual crop types. These give a guide as to what approach to take to either reduce grain damage or increase threshing efficiency.Watch for wear: Significant wear in key threshing components (cylinder, concave etc) can result in more grain damage as the operator tries to correct resulting losses by increasing drum speed or reducing concave clearance. Also, check the basic setting of the concave ensuring parallel clearance across the drum width and the correct front to back clearance.Setting up: Setting the combine to separate the awn from the grain, while minimising grain damage, can be a particular challenge. Adding de-awner plates is recommended with some machines but this can reduce threshing capacity and careful adjustment is required to prevent grain damage.Drum settings: Cylinder (drum) speed and concave clearance play a huge role in threshing and grain damage. Slower drum speeds and wider concave will reduce grain damage, so start at this most gentle end of the scale, slowly increasing drum speed and reducing concave clearance to improve threshing. Always change one setting at a time and check for losses and damage and record your adjustment.Loading: Keeping the threshing element properly loaded is important. If throughput is reduced because of slow speed, grain damage can increase. This is because there may not be sufficient cushioning from the correct volume of material going through the drum.Sieves: Sieve settings are also important as the volume of grain going through the returns system for re-threshing should be kept low to reduce grain damage in re-threshing.Grain augers and elevators: Chains and flights on elevators should be correctly adjusted and free from excessive wear. Unloading augers should be engaged gently and disengaged as soon as the grain flow dwindles, as partly full augers are more likely to damage grain.Mature grain: With barley, removing the awns can be quite difficult, particularly if the grain is just ripe. More severe threshing with faster cylinder speeds and tighter concave clearances is used to try and remove the awn. This can increase damage. It can often be wise to wait a day or two as the awn will come off more easily with less aggressive settings and less risk of grain damage. However, this is difficult to do when moisture is low, harvesting weather is good and the risk of brackling is real. When the awns are left attached, this will result in a reduced specific weight (KPH), which could also lead to the sample being rejected in some markets. Remember, the exact approach to be taken depends on the combine model and you should always be guided by the manufacturer’s information, where provided. But that may only be the starting point – adjust carefully in a methodical way and assess grain damage, threshing and combine losses until the correct balance is achieved.
The issue of grain skinning has again raised its head at the start of the 2016 malting barley harvest. In this article, Teagasc’s Dermot Forristal gives guidance on combine settings to help reduce this element of the problem but skinning is likely to be more complex than just a combine setting issue.
Where has the problem come from? Has it been there all the time and are we only seeing it now because it is a rejection issue? There is little doubt that it is a real issue when a malting premium is at stake, but is it of massive consequence to either malting or brewing? While acknowledging the great work being done by our malting industry, growers and others rightly ask to what degree specifications can continue to be tightened in a product that is subject to the annual vagaries of nature and weather.
Are the skinning (and KPH) cut-off criteria set by the malting barley assemblers justifiable? How much is malting efficiency affected by these levels of skinning? If the effect on malt yield is modest, and the occurrence of skinning is varietal or season-dependent, are assemblers shooting themselves in the foot by exacting such standards? Acknowledging the need for concern, one must wonder why this appears to be an increasing issue?
Are we seeing variety weaknesses? Could this be a problem that is being bred into varieties as other malting quality criteria are edged up or down? While maturity and combine settings have a part to play, the industry must avoid varieties with such quality weaknesses. Livelihoods are at stake.
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