Potato Cyst Nematode pest resistance and tolerance put to test at new Hutchinsons trial site at Mildenhall
PUBLISHED: 06:00 02 August 2017
Experts are looking at the performance of potato crops hit by Potato Cyst Nematode (PCN), a roundworm pest, at a series of trials near Mildenhall.
Growing potato varieties that are both resistant and tolerant to PCN holds the key to tackling one of the biggest threats to UK crops, according to agronomy firm Hutchinsons.
The firm’s new Fenland potato demonstration site near Mildenhall is looking at how 15 leading varieties differ in their resistance and tolerance to the pest under a high pressure situation.
The aim is to improve the limited information on varietal tolerance to PCN available from breeders and dispel some of the misconceptions around the role of “resistance”, explained John Keer from Richard Austin Agriculture, who is managing the trial with his colleague Michael Rodger.
“Resistance and tolerance are not linked. There is a crucial difference growers have to remember,” he said.
Resistance is the ability of a variety to affect the multiplication of PCN. Full resistance prevents formation of cysts on the root system, while partial resistance reduces the formation of cysts. Either type has the effect of allowing a gradual reduction in PCN levels in the soil.
But resistance tells you nothing about the crop’s ability to produce a reasonable yield when grown in the presence of PCN - or its tolerance.
“Generally, tolerant varieties produce larger root systems and are more vigorous in their growth habit,” he said.
Initial PCN counts from multiple samples taken across the trial site ranged from 36-53 eggs/g of soil, all of which was identified as Globodera pallida, now the most widespread PCN species in the country.
Replicated plots of the 15 varieties were planted on May 10. The performance of each one will be compared with and without a nematicide (Nemathorin at 30kg/ha) and taken through to harvest when yield, grade and final PCN count can be assessed.
“The black Fen soil on this site is very forgiving and all varieties look good at the moment,” said Dr Keer. “The really interesting thing will be the final PCN count from soil samples taken after harvest to see which varieties have helped reduce PCN pressure and which have not.”