Winning ways with strobs
Agronomy on show
Agchem distributor Profarma opened up its agronomy trial plots during the show season last month. Gilly Johnson joined the visitors.
IF YOU want to find out what will be on offer from your distributor in years to come, take a tour round the companys agronomy development trials.
Farm manager Martin Davies doesnt have to travel far. Profarma has an extensive trial site on his 580ha farm – part of the CWS group – at Cockayne Hatley, north of Royston, straddling the Cambs/Beds border.
New products that have caught Mr Davies attention are:
• BB5 – a water conditioner which buffers pH and aids uptake of chlormequat and Moddus, as well as other products such as pre-harvest Roundup. "Even on this heavier soil type theres a distinct greening effect," says Profarmas Dr Mark Palmer. "Weve seen tremendous results – up to 1t/ha difference – from BB5 on lighter to medium soils, thanks to increased rooting. And following a wet autumn, anything that helps rooting is useful." BB5 is about £2-3/ha.
Mr Davies verdict: "Im impressed with the results but does the shorter height of the crop reflect better lodging resistance? And we spray at reduced water volumes – theres still a lot to learn about new wetters in these conditions."
• Transcend is a fungicide enhancer which is a cocktail of different wetters, brought in from the US. Profarma trials indicate improved activity against yellow rust and septoria in particular when added to triazoles and strobs; cost is £3.50/ha. "Average yield response has been 0.25-0.35t/ha," says Dr Palmer. "It can be used at T1 and T2 timings. It improves curative effect on yellow rust." On Brigadier, visual effect is marked, agrees Mr Davies.
Winning ways with strobs
DONT use strobs on inherently fertile soils, warns Dr Palmer. "Our trials on highly productive soils at Coldham and Goole, where vegetables are included in the rotation, indicate that two half-dose triazole treatments may be all you need. And its cheaper…" Strobs could be a disadvantage in these situations, increasing lodging risk and keeping the crop green for too long.
But on medium to light soil types there is more mileage to be gained from the new chemistry, he says. "Weve seen an extra 1t/ha over and above triazole treatments. The effect could be enhanced when dose rates are increased from half rates to full rates on the lighter soils."
Many growers on heavy to medium soils will use strobs, but at half rates. "By and large youll see the 1t/ha yield increase. In seasons with high disease pressure, such as this year, there could be benefits from moving to full doses."
Adjustments to strob rates on more disease resistant varieties are more tricky with the formulated mixtures. "Use straight materials such as Ensign or kresoxim-methyl," says Dr Palmer. "Then you can go down to low strob dose while maintaining a robust triazole input."
The company has re-thought its advice on strob programmes in the light of the new FRAC guidelines to avoid resistance, which limit the number of strob sprays to two. In general, its the final Amistar ear wash thats being dropped, rather than one of the T1 or T2 strobs. Alternative ear wash treatments such as Folicur are being used.
But thats Profarmas strategy – Mr Davies has gone down a different route. One section of the trials field is devoted to CWS farm managers own fungicide programmes, which will be taken to yield. Mr Davies reckons hes in with a winning chance.
"Weve used a three-spray treatment on a plot of Consort, which mirrors pretty much what were doing on the farm here."
His recipe? A T1 of half-rate Opus with Bravo at 1 litre/ha; a T2 of full rate Amistar with just 0.3 litres/ha of Opus; and then a T3 of half-rate Amistar.
Although some agronomists are disputing the need for the two-spray FRAC limit on strobs, both Dr Palmer and Mr Davies are complying. "As responsible producers, weve no choice," says Mr Davies.
Problems with weak straw stopped soft feed wheat Drake from making the grade as a mainstream variety, but it has found a useful niche on more marginal soils, says Dr Mark Palmer. "Early sown at low seed rates it does well. Weve had 10t/ha yields from 75 seeds/sq m, on lighter land where Riband would come in at between 7-8t/ha." Drake tillers and roots vigorously. It does even better with two full rate strobs and extra nitrogen, according to Profarma trials. At 150kg N/ha, yield with two full-rate Mantra sprays (GS31 and GS39) was 11.3t/ha. Boosting the N to 200kg N/ha raised yield to 12.3t/ha. Reducing the strob dose to two half-rate treatments put the yield back to 11.2t/ha.