There is hardly a day that goes by that I am not talking to growers about the problem with late-green tillers in spring cereals. It’s not just barley, as it is also a problem in oats and wheat, and it presents the same dilemma – to spray or wait?
There is no single answer to this question. The easy answer is to spray, but both the decision and the timing will be important.
Historically, late-green tillers were little more than a nuisance.
While they are an even bigger nuisance this year, it seems likely that they will contribute to grain and straw yield – possibly a half tonne per acre or more. Because they may contribute seriously to yield, they should be allowed to fill as much as possible before burning off or harvesting.
The major constraint is the risk of straw breakdown in the early crop
In the case of malting barley, immature grains are higher in protein than mature grains – as more starch comes into the grains it dilutes the protein content.
So, if a malting crop is worth leaving, the overall protein will fall a little until the late grains get to cheesy ripe.
Yield may also increase up to that point. Hold back on any action for as long as is practical.
The major constraint is the risk of straw breakdown in the early crop or, more precisely, the risk that any brackled straws can drop their heads on the ground. This is highly likely in a very thin crop, but unlikely where there is a dense crop of late tillers.
Scenarios and options for tackling late green tillers
This short piece presents a few different scenarios and suggests appropriate courses of action.
1 A barley crop grown for malting: the first decision is to ask if your crop has any chance of making the required quality specs? Consult with your end user to help make this decision. With yield well back, premium products may be scarce.
If your crop is unlikely to be accepted, you can spray. If not, delay harvesting as long as is practically possible to maximise grain fill. The more grain fill you can get in the late tillers the more yield you may get and the lower the composite protein may be.
2
An oat crop grown for the food markets: the situation here is pretty much the same as with malting barley – if the buyer feels it may make the grade, do not spray it off and hold off on harvesting for as long as is practical.
3
A crop that will not make premium grade or a feed crop: some crops may not merit spraying off, either because the tillers are very late, and the grains will be small and blow out somewhere in the system.
Other crops have very few late tillers in most of the crop. Where a crop is to be sprayed off, delay the spray for as long as possible. That will mean that your ‘A’ crop will be over-ripe for application (<30% moisture) while timing on the late tillers (‘B’ crop) will be too early – there will have to be compromise.
Indeed, timing may be more driven by the risk of straw breakdown and ear loss.
4
Crop is not bad except for a few bad patches hit in May by the drought: regardless of the target market, do not spray off a crop unless it is necessary.
Where there are low levels of green tillers with a few bad green patches, you might cut your crop at the appropriate time and by-pass the green patches.
These are likely to be at least 10 days later maturing, so you might spray them off when the rest of the crop is cut or leave them to ripen.
While this seems challenging, we need a proportion of the crop that is not sprayed to help with residue levels, etc.
5
Crop has relatively few green tillers except in the tram-tracks: if it’s a feed crop, you might just do nothing and cut it when the time is right.
If it’s a premium crop, you should avoid getting too many green grains into the sample. Three options come to mind.
Leave the tramlines when harvesting and cut them immediately after for feed. Drive all the tramlines using a slightly wider wheel to roll down the bulk of the green tillers so they pass under the blade of the combine. Fit a single nozzle for each tram track and spray on a modest rate of glyphosate in the tracks only. Set the nozzle to spray below the level of the heads so that it is not sprayed on to the grain. This will kill the green stems and any grass in the tramline.
There is hardly a day that goes by that I am not talking to growers about the problem with late-green tillers in spring cereals. It’s not just barley, as it is also a problem in oats and wheat, and it presents the same dilemma – to spray or wait?
There is no single answer to this question. The easy answer is to spray, but both the decision and the timing will be important.
Historically, late-green tillers were little more than a nuisance.
While they are an even bigger nuisance this year, it seems likely that they will contribute to grain and straw yield – possibly a half tonne per acre or more. Because they may contribute seriously to yield, they should be allowed to fill as much as possible before burning off or harvesting.
The major constraint is the risk of straw breakdown in the early crop
In the case of malting barley, immature grains are higher in protein than mature grains – as more starch comes into the grains it dilutes the protein content.
So, if a malting crop is worth leaving, the overall protein will fall a little until the late grains get to cheesy ripe.
Yield may also increase up to that point. Hold back on any action for as long as is practical.
The major constraint is the risk of straw breakdown in the early crop or, more precisely, the risk that any brackled straws can drop their heads on the ground. This is highly likely in a very thin crop, but unlikely where there is a dense crop of late tillers.
Scenarios and options for tackling late green tillers
This short piece presents a few different scenarios and suggests appropriate courses of action.
1 A barley crop grown for malting: the first decision is to ask if your crop has any chance of making the required quality specs? Consult with your end user to help make this decision. With yield well back, premium products may be scarce.
If your crop is unlikely to be accepted, you can spray. If not, delay harvesting as long as is practically possible to maximise grain fill. The more grain fill you can get in the late tillers the more yield you may get and the lower the composite protein may be.
2
An oat crop grown for the food markets: the situation here is pretty much the same as with malting barley – if the buyer feels it may make the grade, do not spray it off and hold off on harvesting for as long as is practical.
3
A crop that will not make premium grade or a feed crop: some crops may not merit spraying off, either because the tillers are very late, and the grains will be small and blow out somewhere in the system.
Other crops have very few late tillers in most of the crop. Where a crop is to be sprayed off, delay the spray for as long as possible. That will mean that your ‘A’ crop will be over-ripe for application (<30% moisture) while timing on the late tillers (‘B’ crop) will be too early – there will have to be compromise.
Indeed, timing may be more driven by the risk of straw breakdown and ear loss.
4
Crop is not bad except for a few bad patches hit in May by the drought: regardless of the target market, do not spray off a crop unless it is necessary.
Where there are low levels of green tillers with a few bad green patches, you might cut your crop at the appropriate time and by-pass the green patches.
These are likely to be at least 10 days later maturing, so you might spray them off when the rest of the crop is cut or leave them to ripen.
While this seems challenging, we need a proportion of the crop that is not sprayed to help with residue levels, etc.
5
Crop has relatively few green tillers except in the tram-tracks: if it’s a feed crop, you might just do nothing and cut it when the time is right.
If it’s a premium crop, you should avoid getting too many green grains into the sample. Three options come to mind.
Leave the tramlines when harvesting and cut them immediately after for feed. Drive all the tramlines using a slightly wider wheel to roll down the bulk of the green tillers so they pass under the blade of the combine. Fit a single nozzle for each tram track and spray on a modest rate of glyphosate in the tracks only. Set the nozzle to spray below the level of the heads so that it is not sprayed on to the grain. This will kill the green stems and any grass in the tramline.
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