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Growers advised to manage PCN hotspots

Potato Cyst Nematode (PCN) is considered the most economically damaging pest to potato crops in the UK. And, as eradication isn’t possible, experts advise that effective disease management is crucial.

Potato Cyst Nematode (PCN) is considered the most economically damaging pest to potato crops in the UK. And, as eradication isn’t possible, experts advise that effective disease management is crucial.

Following the loss of Telone, Dr John Keer, from Richard Austin Agriculture advocates the need for PCN research surrounding the use of metam sodium.

“Metam 510 (Containing metam-sodium) is the only remaining soil fumigant in the industry capable of controlling PCN. As a result, research into effective control programmes is imperative. 

”It is vital to manage PCN levels, as we will never eradicate the pest entirely.”

John recommends that sampling fields to monitor levels of PCN is part of a strategy to effectively gain control. “Intensive field sampling enables hot spots to be identified and assists a better understanding of the PCN pressures present in fields.”

Where PCN hot spots are revealed, Metam is an ideal treatment choice to bring these areas in line with PCN levels in the rest of the field, and occasionally whole fields will require treatment where PCN numbers have risen dramatically.

However, John advises that application conditions are critical for Metam. “The soil temperature must be as high as possible and the tilth should be similar to that of a fine seedbed; this is to maximise the volatility of the MITC gas within the soil.” He adds, “The moisture goes hand in hand with the tilth; if you get one right the other will follow.”

He comments that when it is possible to satisfy the correct soil conditions, then this is the time to be applying Metam. But he reminds growers that Metam is not seen as a ‘routine’ application and generally only used to get PCN back into control.

John also states that using a granular nematicide such as Mocap (Containing ethoprophos) at planting, reduces any PCN multiplication during cropping, thus delivering a programme of effective management that can be sustained throughout the season.

Richard Austin Agriculture – Metam 510 trial

A replicated small plot trial assessing the efficacy of Metam 510 has been coordinated, with results now looking promising.

Metam was applied at a rate of 400l/ha and early indications are showing that visually, the differences in vigour are spectacular, says John Keer, who advises that crop results are still coming in, and yet to be  statistically analysed.

John goes onto detail the treatment programme; “It started with soil sampling which identified several hot spots with very high PCN counts.

“As a result of the PCN pressure, we treated with Metam 510 and a granular nematicide – it was a programmed approach which was necessary due to the initial high infestation levels.”

He remarks that at the levels found, it would not have been economically viable for a commercial grower to grow a crop of potatoes in those conditions, but he is encouraged at the initial indications from the trial which suggest that the yield potential will be met.”

Full trial results are expected shortly. John concludes by reminding growers that the management of PCN is vital to meet yield potentials and keep the pest under control across the UK.