Staying ahead of the game in potato pest control
AHDB is providing fresh focus on the management of Potato Cyst Nematode in 2017 and beyond.
The new Strategic Potato (SPot) Farm West at Heal Farms, Shropshire will be specifically PCN-focused.
A range of complimentary demonstrations will take place on farm to help visitors make informed decisions at their own businesses. An updated PCN management guide has been drafted and will be released in July. This will be distributed at SPot West events and can be requested directly from AHDB’s knowledge exchange team.
This guide presents a summary of the latest national prevalence survey and describes control methods. None of these methods used in isolation will prevent infestation or eliminate established infestations, so recommendations are given for best practice measures that will offer a sustainable strategy for PCN management in the long term, in an integrated pest management programme.
Relevant regulations have changed since the introduction of Directive 2007/33/EC, the PCN Control Directive
There is no single method of PCN control. Most experts will recommend an ‘integrated approach’. Local and historical conditions will have a large impact on the final mix of methods chosen.
The key is to stay ahead of the game. In much of our industry, potatoes are grown on rented land where often the grower has little influence in controlling volunteer potatoes in subsequent rotations, thus allowing the PCN lifecycle to continue. It becomes vital to test for PCN in this situation, and I would normally recommend testing to 40 cores per hectare grid.
In the absence of a host, eggs hatch over an extended period, so that the numbers left viable decline each year. When potatoes are grown, specific chemicals exuded by the roots of both susceptible and resistant cultivars stimulate most (up to 90 per cent) of the eggs to hatch.
Juvenile nematodes are attracted to potato root tips, invade them and feed within them. This causes much of the damage to the crop, by stunting root growth and reducing uptake of nutrients and water from the soil. This feeding can cause considerable yield loses without necessarily producing large numbers of cysts, especially in resistant, intolerant varieties.
Juvenile nematodes develop within the root. On susceptible cultivars they develop and small (0.5mm) round females eventually protrude through the surface of the root to form a cyst. In July and August they are visible to the naked eye on the outside of the root.
Tolerant varieties can withstand or recover from damage and produce a yield. Resistant varieties can prevent or restrict nematode reproduction, although the yield may be severely impaired.
An updated PCN management guide has been drafted and will be released in July. This will be distributed at SPot West events, including the Open Day on August 17. It can be requested directly from AHDB’s Knowledge Exchange team.
To register for our Open Day please visit our website https://potatoes.ahdb.org.uk/events/spot-west-farm-walk
Stuart Baxter, AHDB Potatoes