HGCA GUIDE TO MAKEMOST OF RECENTWORK
HGCA GUIDE TO MAKEMOST OF RECENTWORK
The cancellation of this years Cereals event deprived
growers of the opportunity to see for themselves how
the latest HGCA-funded research can be used to
maximise gross margins. But over the following pages
Louise Impey provides a virtual visit to the planned
HGCA demonstration area
VISITORS to the HGCA stand at Cereals 2001 would have encountered plots representing three different arable situations, with each plot managed according to either conventional agronomy methods or in line with the latest research findings.
"The plots were designed to demonstrate the value of recent research," says demonstration manager David Parish of ADAS. "They were also an attempt to pull much of the work together, and show how it can be used to really improve crop performance."
The three situations chosen were typical of those on many arable units and provided three contrasting management situations, says Mr Parish.
"We decided on an early-drilled wheat crop after a break, a high fertility site growing an early-drilled wheat after a break and a late-drilled wheat crop after either beans or potatoes."
IMPORTANT TOPICKVARIETY CAREFULLY
Variety choice can have a key effect on crop management and performance, and the HGCA plots aimed to show just how important that is.
With an early-drilled crop, Consort is the first choice of many growers and it would have featured in the conventional plots, says Mr Parish. "It is popular because it has many desirable characteristics.
"However, Consort is very susceptible to disease, especially septoria, and needs a high level of fungicide input, so is at risk from significant yield loss in a difficult spraying season, if applications get delayed."
Variety choice on the other half of the plot for early drilling was Claire. "It is also suited to the early sowing date, as it has very slow speed of development characteristics. And it has a better level of disease resistance, so is less vulnerable to yield loss."
Mr Parish reminds growers that drilling early increases disease pressure. "But if you get the fungicide timings wrong with Claire, you pay a lower price. In a difficult season, the yield impact will be less."
With the right timings, Claire will save £15/ha in fungicide costs by using lower rates, he calculates. "Its only weakness is that it is taller. But if you get the seed rate right, there wont be a greater risk of lodging."
In a high fertility situation, Savannah would be the choice of many growers for its yield ability. "It is a very good feed wheat, but its standing is a bit weak.
"Another variety of the same type is Equinox, even though it yields 3% less. In a high lodging risk situation, you could easily lose more yield than that.
"The HGCA plots were going to feature Equinox because we believe it is important to eliminate the greatest threat to yield potential."
With a crop drilled in mid-October, the yield gap between milling and feed varieties has narrowed. Mr Parish opted for Malacca in this situation to get greater financial output and to grow a faster developing variety.
"We dont need such a big milling premium to fill the gap, so Malacca could do better in this situation than Consort, which many people would have gone for. It also means that the farm would have a nice mix of varieties, each for a different market."
NSUPPLY IS ACRUCIAL TOOL
Using nitrogen supply as a tool to manage crop performance is a fundamental part of HGCA-funded cereal research and plots at the Cereals event would have shown just how useful that tool can be when used correctly.
With the managed plots, the aim was to get to a crop canopy or Green Area Index (GAI) of 6. There are two sources of nitrogen available to the plant, soil N and bagged fertiliser.
"On the HGCA plots, we did a soil N test to determine the reserves, which were lower than expected because of the amount of winter rainfall," says Mr Parish. "The high fertility site had 50kg/ha more than the others, so we had to allow for that in our planning."
It is important to have enough shoots and tillers with low seed rate crops, so his plan was to apply 40kg/ha N as an early dressing to the Equinox on the high fertility site. "We needed to keep all the tillers to keep on target. If you starve the crop, you get greater tiller loss."
The Claire and Malacca canopy managed plots were to receive a maximum of 250kg/ha, with the last 40kg/ha being subject to a decision made in late May. "That would have depended on canopy progression."
The Equinox would have had a maximum of 160kg/ha because there was more in the soil. "Again, the last 40kg/ha would be decided on late season. The aim with this application is to keep the canopy green for as long as possible."
If the canopy does get ahead, there are two possible reasons, explains Mr Parish.
"The crop can pick up more N than the soil sample predicts. And it might use fertiliser N more efficiently than the assumed 60% level."
Conventionally managed plots were to get a total in the region of 180kg/ha, with an early 40kg being followed up with two 70kg doses in early and late April.
TARGETING NUMBEROF SHOOTS…
Managing a crop to achieve a target number of shoots in June can help boost crop performance, says Mr Parish.
"With the plots featuring the latest research results, we worked to target shoot numbers of between 420-560 shoots/sq m to show how the wheat plant compensates for lower seed rates by increased tillering."
Every variety has the capacity to compensate, he says. "There are less ears in June, but each ear has more grains and there is a higher thousand grain weight (TGW). Crops look more open, but they are on course for optimum yields."
EXPLOIT THE REDUCTION IN SEEDRATES
Most growers are still failing to take advantage of reduced seed rates, which can cut costs and ease crop management. The HGCA plan for Cereals 2001 was to show the benefits of such a reduction.
The early-drilled Consort and Savannah were sown at conventional seed rates of 180kg/ha, to give 330 seeds/sq m, as is done on many UK farms.
"We then took on the latest HGCA work and used very low rates of 60-75kg/ha in the other half of the plots," says Mr Parish. "And even though we built in a safety margin of 100% on recent guidelines, we still reduced seed rates by two-thirds."
Grower concerns that particular pest problems prevent them from adopting very low rates are legitimate, he says. "But even when we doubled the research rates, we made significant savings. They represented £18-26/ha depending on the variety, or £9-13/ha where home-saved seed is used."
He reminds growers, though, of the importance of seed-bed conditions when choosing a seed rate. "Increase the rate if seed-beds are poor."
HOWTOCUT GREATRISKOFLODGING
Growers should try not to rely on plant growth regulators alone to control lodging, says Mr Parish. If the right seed rate is used and establishment is on target, lodging risk can be markedly reduced.
"Pgrs arent a guarantee that the crop will remain standing. In a high risk situation, they should not be relied on."
Crops can suffer from either root or stem lodging and pgrs are most effective on stem lodging, he says. "They have a limited effect on anchorage. And in most situations, it is rooting that fails. That is why seed rate is crucial."
Intended use of pgrs on the plots was full rate chlormequat at GS30/31 on the Consort, with a two-thirds rate planned for Claire. The late-drilled Consort and Malacca were also to receive the reduced rate programme.
"But the high fertility site under the conventional regime was to have an early Moddus at GS30, a Moddus/chlormequat mix at GS31 and a late season Terpal – a real belt and braces approach.
"By contrast, the Equinox on the same site was simply to receive a full dose of chlormequat at GS30/31. With the appropriate seed rate, that is all it would need."
TAILORUSEOF INPUTSTO YOURCROP
Making use of inherent disease resistance and the lower disease risk from reduced seed rates can make quite a difference to costs, advises Mr Parish. "Whereas some growers would consider a pre-T1 spray on Consort, to hold septoria, there is no need to follow this course of action with Claire."
At T1, Claire would have received a lower dose than Consort, because of its better disease resistance ratings. "Claire will get septoria, but it can withstand it. So the dose saving is in the region of 15-20%. With Consort, you cant afford to risk septoria getting away.
"Likewise, the T2 or flag leaf spray would have seen Claire getting a half dose of the chosen fungicide mix, while Consort was to have a three-quarter dose. Another saving, this time 25%."
An ear spray was not planned for Claire because judgement was reserved until weather conditions can be taken into account. "If it is wet at early flowering, then a triazole fungicide would have been applied," says Mr Parish.
"But there is no milling premium at stake, so omitting the ear spray with a variety like Claire is an option." The conventionally managed plots were to get a triazole at T3, whatever the conditions.
VARIETYCHOICE
• Eliminate greatest threat to yield loss.
• Save £15/ha with inherent disease resistance.
• Yield gap between feed and milling closes as drilling is delayed.
• Standing power needed on fertile sites.
Three crop scenarios show value of HGCA findings, explains ADASs David Parish.
SEEDRATES
• Savings of up to £26/ha can be made.
• Seed conditions dictate rate.
• Take likely pest problems into account.
Plenty of scope remains for growers to cut seed rates. Cost savings, easier management and better yields can follow, according to HGCA research findings.
LODGINGCONTROL
• Seed rate crucial to prevent root lodging.
• Early season chlormequat enough for most crops.
• High fertility sites will require pgr programme.
FUNGICIDES
• Use lower dose rates on Claire.
• Pre-T1 spray for septoria prone varieties.
• Ear spray dependent on weather.