Article taken from The Press and Journal Magazine
Good establishment of oilseedrape will be even more critical than usual this summer as farmers face a secondseason without neonicotinoid seed treatments. Slow growing crops will be more susceptible to all seeding pests anddiseases, but are especially prone to early attach from cabbage stem fleabeetle, which can wipe out a backward crop as it struggles to come through theground.
However, by following a few simple guidelines, growers can help crops to growaway strongly, tipping the odds very much in their favour. Oilseed rape establishment has been at theheart of Agrovista’s Growcrop Gold trials, carried out over a range of sitesacross the UK over the past six years. Theseshow that the highest yields tend to be achieved with lower seed rates on goodseedbeds with adequate moisture, giving evenly established low plantpopulations in the autumn.
By getting the right plant population from the outset, we stand much betterchance of achieving the optimum canopy toward the end of flowering, which isthe crucial period when a seed is set. The first step to successful establishment is to remove compaction. Oilseed rape is a lazy rooter and needs soilswith plenty of cracks and pores so it can put down the deep taproots thatunderpin high yields. The crop is alsovery intolerant of water logging.
Locating the position of any soil pan is important to cure, rather than createproblems. Use a spade or penetrometerto ensure remedial cultivations are carried out at the right depth. Going too deep will compress the compactionlayer from below and increase wheel slippage. Maintaining moisture in the seedbed is critical, so cultivations shouldbe kept to the minimum possible to achieve a seedbed that contains a mix offine soil and small aggregates. We wantto encourage good seed-to-soil contact while minimising capping. It’s a fine balance, but the trick is not toover-work soils and roll them straight after drilling to conserve moisture inthe surface layer.
Optimum seed depth is 15mm, though growers should check pre-emergence herbicidelabels first to ensure this is permitted. The best way to achieve this is by conventional drilling, though subcasting can achieve good results, or coulters can be fitted to the back ofsubsoiler legs. Manufacturers are alsodeveloping their own systems. Establishing the correct plant population is vital to achievingconsistent yields. Several years ofGrowcrop Gold work has shown that highest yield are typically achieved bysowing 15-20 seeds per m of row to produce 12-15 plants.
As a rule of thumb, 40-60 seeds/sq m will achieve an acceptable result at12.525cm spacing, where normal establishment is expected. However, at produce 30 seeds/m of row, soseed rates should be reduced accordingly. Establishing more than 12-15 plants creates too much early competition. Plants fight for light, which reduces establishmentand tends to produce tall, spindly plants that are more prone to pestattack. Too high a seed rate also wastesmoney. Correct plant spacing alsoencourages crops to produce open, branched architecture the following springthat makes best use of sunlight and optimises yields.
Where higher levels of fleabeetle attack are predicted, seed rates can be increased but narrower row spacing’smust be used rather than cramming more seed along the row.
The rule of not exceeding 60 seeds/sq m should still be observed. If growers remain uneasy they should choosevarieties with the best early autumn vigour.
Good establishment of oilseedrape will be even more critical than usual this summer as farmers face a secondseason without neonicotinoid seed treatments. Slow growing crops will be more susceptible to all seeding pests anddiseases, but are especially prone to early attach from cabbage stem fleabeetle, which can wipe out a backward crop as it struggles to come through theground.
However, by following a few simple guidelines, growers can help crops to growaway strongly, tipping the odds very much in their favour. Oilseed rape establishment has been at theheart of Agrovista’s Growcrop Gold trials, carried out over a range of sitesacross the UK over the past six years. Theseshow that the highest yields tend to be achieved with lower seed rates on goodseedbeds with adequate moisture, giving evenly established low plantpopulations in the autumn.
By getting the right plant population from the outset, we stand much betterchance of achieving the optimum canopy toward the end of flowering, which isthe crucial period when a seed is set. The first step to successful establishment is to remove compaction. Oilseed rape is a lazy rooter and needs soilswith plenty of cracks and pores so it can put down the deep taproots thatunderpin high yields. The crop is alsovery intolerant of water logging.
Locating the position of any soil pan is important to cure, rather than createproblems. Use a spade or penetrometerto ensure remedial cultivations are carried out at the right depth. Going too deep will compress the compactionlayer from below and increase wheel slippage. Maintaining moisture in the seedbed is critical, so cultivations shouldbe kept to the minimum possible to achieve a seedbed that contains a mix offine soil and small aggregates. We wantto encourage good seed-to-soil contact while minimising capping. It’s a fine balance, but the trick is not toover-work soils and roll them straight after drilling to conserve moisture inthe surface layer.
Optimum seed depth is 15mm, though growers should check pre-emergence herbicidelabels first to ensure this is permitted. The best way to achieve this is by conventional drilling, though subcasting can achieve good results, or coulters can be fitted to the back ofsubsoiler legs. Manufacturers are alsodeveloping their own systems. Establishing the correct plant population is vital to achievingconsistent yields. Several years ofGrowcrop Gold work has shown that highest yield are typically achieved bysowing 15-20 seeds per m of row to produce 12-15 plants.
As a rule of thumb, 40-60 seeds/sq m will achieve an acceptable result at12.525cm spacing, where normal establishment is expected. However, at produce 30 seeds/m of row, soseed rates should be reduced accordingly. Establishing more than 12-15 plants creates too much early competition. Plants fight for light, which reduces establishmentand tends to produce tall, spindly plants that are more prone to pestattack. Too high a seed rate also wastesmoney. Correct plant spacing alsoencourages crops to produce open, branched architecture the following springthat makes best use of sunlight and optimises yields.
Where higher levels of fleabeetle attack are predicted, seed rates can be increased but narrower row spacing’smust be used rather than cramming more seed along the row.
The rule of not exceeding 60 seeds/sq m should still be observed. If growers remain uneasy they should choosevarieties with the best early autumn vigour.