Crop Watch: T1 barley fungicides looming

In the north, early wheat crops were at T0 timing, but the bulk were scheduled for mid-April, said Arable Alliance’s David Martindale from Yorkshire.

Rust-susceptible varieties were receiving a triazole mixed with a growth regulator, he said. “But with Septoria tritici levels being relatively high chlorothalonil is being applied on earlier crops.”

Winter barley looked well and would soon receive a T1 fungicide, he added. “It may be tempting to cut back rates. However, T1 is where the highest yield responses occur so it could be false economy to trim back too far.”

Net blotch was the main disease present with low levels of mildew, brown rust and rhynchosporium. With Fandango (prothioconazole + fluoxastrobin) still unavailable he planned to fill the gap with prothioconazole mixed with a strobilurin. “The new fungicide Bontima (isopyrazam) has gained approval just in the nick of time and looks to be a good alternative.”

In Hampshire, winter wheat was at GS29-30 and was ready for T0 fungicides, while winter barley had reached GS28-29 and was nearly ready for T1 applications, said Agrovista agronomist Swaran Bachoo. “A large number of fields require blackgrass treatment and some need broad-leaved treatment – be careful not use complex tank mixes for fear of crop damage.”

When mixing a T0 fungicide with Atlantis growers should make sure only recommended products were used, he added. Spring barley and linseed crops were starting to emerge, but looked pale due to two sharp frosts last week. Spring beans were at the cotyledon leaf stage and had some leaf notching symptoms from pea and bean weevil attack, he said.

Wheat crops were being monitored for yellow rust, said AICC agronomist Dan Dines from Wiltshire. “But as yet there are no problems to report.”

T0 fungicide applications had just begun in forward wheats, but the majority of crops would be treated next week (w/c 12 April), he said. “Treatments are being based on chlotothalonil, either with or without a triazole, and a herbicide is being included where required.”

Winter oilseed rape was developing slowly, but would still receive a fungicide with plant growth regulator activity at the green/yellow bud stage, he said. “This will also be the start of the sclerotinia control programme and crops should be monitored for pollen beetle until flowering.”

Spring linseed drilling would being once soils dried and warmed up, he said. “There are a few more options for broad-leaved weed control in linseed this season, but they are based on SOLAs, which means the grower carries all the risk.”

AICC agrononmist Ruth East from Lincolnshire reckoned warmer temperatures in March helped winter crops respond to early-applied nitrogen allowing them to green up. “Oilseed rape crops which had lost outer leaves are now looking respectable and the spring vigour of hybrids varieties is really noticeable.”

These would be treated using a fungicide with growth regulatory effects and a trace element mix containing boron, she said. There was little evidence of light leaf spot and grassweed control had been effective, she said, “especially with the later applications of propyzamide and carbetamide”.

However, Atlantis (mesosulfuron +iodosulfuron) applications had not worked as well as expected. “Plants that looked dead six weeks ago are beginning to show signs of recovery with small new roots and leaves emerging.”

Click below for the full report from each region

Crop Watch North – David Martindale

Crop Watch South – Swaran Bachoo

Crop Watch West – Dan Dines

Crop Watch East – Ruth East