Now is a good time to check growing potato crops for signs of viruses such as PVY and potato leaf roll virus, according to NIAB.

Levels of Potato virus Y in tubers last year were very high, and if they were untested and used as seed, then inoculum levels will be high, it said. The problem could have been compounded by the mild winter and early aphid movement, which could have also transmitted other mosaic viruses.

NIAB’s plant pathologist Anna Gordon said growers should be aware that yellowing and rolling of leaves could also be due to early blackleg or Erwinia infection, so lab testing may be needed to get a clear answer.

“A high proportion of potato samples sent in to the clinic so far have revealed the presence of Erwinia and the recent rain will be helping spread the disease. The sooner it’s identified by us, the sooner management decisions can be implemented.”

Growers wanting to identify what viruses or diseases are present in sick crops can send leaves taken from the 10 sickest looking plants to NIAB for testing.