A battle with brown rust last year has seen Ollie Cook drop Crusoe from the rotation at Shillingford Farm in Oxfordshire and replace it with a new Group 1, SY Cheer, which has a better brown rust resistance score.
“I wouldn’t like to guess at the yield loss last season and although the Crusoe did make the protein for milling, it struggled on the specific weight because the high brown rust pressure resulted in smaller grains.
“As part of an integrated pest management (IPM) approach I have SY Cheer in the ground this season which has an AHDB Recommended List brown rust rating of 6, better than Crusoe, with 3.
“Although no two years are the same in farming, rusts are our biggest problem in the wheat here at Shillingford. We are right in the middle of the Thames valley and get pretty warm in the summer but we do get septoria and occasionally mildew as well, however, it is variety specific.”
IPM measures
Jared Bonner Business Development Manager, BASF said, “Growing resistant varieties is a cornerstone of IPM, however, most conventional wheat varieties are moderately susceptible or susceptible to brown rust and growers need to be aware that once established in a crop, brown rust is very difficult to remove.“
Aoife O’Driscoll, Senior Specialist, Niab, agreed, “Brown rust’s infection efficiency is much better than that of yellow rust; it is 8 times more infectious. If you have brown rust then you need to treat it like a biosecurity issue, you need to get rid of it as soon as possible.“
“Regular monitoring of crops to ensure early detection and timely intervention is essential. Growers also need to be aware that brown rust cycles very quickly in warm weather, quicker than yellow rust,“ cautioned Jared.
Fungicide Selection
“One clear learning from the season 2024 was that focussing solely on septoria is not a good idea. Although in the UK septoria predominates, it is rarely in isolation and growers want to achieve broad spectrum disease control with their fungicide programmes.
“Although last year’s early brown rust epidemic was unusual, even in more ‘normal’ years this disease should feature in T1 and T2 decision making, especially on susceptible varieties. The SDHI azole combination planned for septoria at these timings must also be effective on brown rust.
“Revystar XE (mefentrifluconazole + fluxapyroxad) gives effective broad spectrum control of septoria, brown and yellow rust,” said Jared.
Aoife explained, “As an azole, there is no question about it that mefentrifluconazole (Revysol) is the strongest azole that we have against brown rust and one of the strongest on septoria and yellow rust as well.
“In order to protect the two new SDHIs we have had in the last year, we should use them in combination with an azole; Revysol, as a broad spectrum azole that covers most of the target diseases really is the standout. Using Revysol in the programme is really important.“