The continued spread of potato cyst nematode (PCN) was high on the agenda at Potatoes in Practice as Jo Learmonth reports
Professor Ian Toth, senior scientist at The James Hutton Institute (JHI) told growers that urgent action is needed against PCN or there might be no land left to plant potato seed on within the next 25-30 years.
He said: “We need a co-ordinated approach, through the entire potato industry but more than that we need an integrated approach where we have growers, testing laboratories, agronomists, policy, research providers, consumers and processors all working together.
“The Plant Health Centre which I am director of has commissioned work to do a number of things: pull together lists of the resistant varieties to the different Globodera species; look at recent breeding programmes to see where we are in respect of resistance that is useful for cultivars in Scotland; review options for effective PCN management in other countries; develop models for the PCN lifecycle and do extended grower surveys to see if there are any impediments which stop them dealing with PCN. We will also look into the perception that short term profits on rented land might be taking over from long term management of owned land.”
Historically G. rostochiensis has been the most common species of PCN, however, over the last decade there has been a big shift from G. rostochiensis to G. pallida.
Prof Toth said: “Fifty per cent of all the potato production in Scotland is varieties highly resistant to G. rostochiensis, Maris Piper being a prime example. However, only about 10 per cent of the area we produce has any resistance to G. pallida so it is becoming a bigger and bigger problem, doubling every six or seven years over the last decade. Varietal resistance is very important and we need to use more resistant varieties in our production.”
A recent survey by Science and Advice for Scottish Agriculture (SASA) found that over 40 per cent of growers were not aware of whether the varieties they were using were resistant to PCN or not.
Prof Jon Pickup of SASA said: “If you grow a susceptible variety, with no nematicide treatment in a rotation less than one in 13 years the PCN population will increase. If you grow a resistant variety then you get the rotation down to one in 5. Using a nematicide helps and can bring rotation periods down.”
PCN spreads on machinery throughout the rotation so biosecurity is crucial. Pete Grewar, Grewar Farming said: “We are always conscious of hygiene. On our seed crops we have a fairly wide rotation, one year in nine, we are very strict on groundkeepers and machinery is all cleaned down and disinfected between seed crops. We are fortunate in that our seed enterprise is geographically remote from our ware enterprise so we have no machinery cross over between seed and ware.”