Brown rust risk could be higher than normal this season and it is not just growers in high risk areas that must be prepared to take preventative action, experts have advised.
Some growers may think rust does not affect their farm or is only a late season disease, but higher levels of inoculum after a relatively “soft” winter, increasing variety susceptibility and the development of a new race of brown rust could change this, says Bill Clark from ADAS.
“Areas traditionally at risk will remain so, however we could see rust spreading into the Midlands and further north this season.
“Yellow rust is also about and will develop in wet and cool conditions so where brown rust doesn’t come in, the yellow will be there,” he warns.
The Arable Group’s Stuart Knight agreed and highlighted the benefits of a preventative spray at T2.
“If not adequately protected, the disease can get hold of a crop in a short period of time, come in after T2 and rob yield significantly. TAG trials have shown that, with the right programme, yield responses to fungicide can easily reach 3t/ha on varieties susceptible to brown rust.”
Strobilurins, such as pyraclostrobin, offer the best brown rust protection at T2, although for curative action at T3, triazoles can be more important, he said.
“Prevention really should be based on a flag leaf triazole plus strobilurin treatment, although those in high risk areas such as the south and east ought to also consider an ear wash as well,” added Mr Clark.