Heat stress under record seasonal summer temperatures could trigger increased risk of an initial Alternaria attack in potato crops, warn crop experts.
Plants suffering from lack of moisture could prove more susceptible to pathogen infection.
Soil moisture deficit will inhibit the uptake of nutrients, which could further stress crops during rapid canopy growth.
Research has shown that stress is a key factor in enabling initial infection of Alternaria alternata to take hold in plants.
Alternaria alternata is a fungus which has been recorded causing leaf spot and other diseases on over 380 host species of plant.
It is an opportunistic pathogen on numerous hosts causing leaf spots, rots and blights on many plant parts.
Affected crops are believed to be more susceptible to the later infection of more devastating A. solani strains of the pathogen, according to Syngenta Potato Technical Manager, Douglas Dyas.
'Earlier infection'
“Successive years of Alternaria leaf tissue testing by NIAB has revealed the A. alternata strain to be the first to appear, typically starting in late June,” he reported.
“But recent weather conditions could trigger earlier infection, particularly in susceptible varieties if they are under stress.”
Mr Dyas urged growers should start their planned Alternaria programmes with 'Amphore Plus', with the aim to take advantage of the product’s difenoconazole content to load up protection in the plant at the start of the risk period.
It comes as warnings that the extremely dry conditions the UK faced put the countryside at risk of devastating fires, warned NFU Mutual.
