While some progress has been made, there is still a substantial area of potatoes left to harvest this year. Last week, growers from as far as Wexford and Donegal gathered in Balrothery, Co Dublin, to attend a potato crop walk organised by the IFA and Teagasc and discussed the many challenges of this growing season.

Diquat decisions

The first topic at hand was alternative desiccation strategies in the event diquat registration was revoked, which was a real concern among growers. Since the meeting last week however, it has been confirmed that diquat will not be reregistered. Merchants will be able to sell the products containing diquat up to 4 May 2019 while growers have until 4 February 2020 to use up supplies. Growers were cautious when desiccating crops this year, ensuring not to cause crop damage due to dry conditions. Signs of diquat damage can be spotted by slicing the potato in half (from point to point) and looking for a brown vascular ring, just in from the skin.

Growers who tried Spotlight this year noted that canopies were very lush and they needed some diquat to help defoliate the crop first. The speed at which Spotlight worked was also a key question posed but the product appears to be faster acting when applied in sunlight. Few growers had been flailing crops this year.

Potato harvest progress

Dry conditions have proven to be a challenge in certain eastern and southeastern areas so the weekend rain would have been welcomed. Slug numbers are reported to be low so few growers applied slug pellets at time of burndown. Growers reiterated that crops are slow to mature this year and achieving dry matters has been a challenge. Small tubers have forced some growers to switch to narrower webs.

Gross yields have been below average, ranging from 12-17t/ac. Many growers in attendance had applied the sprout suppressant active maleic hydrazide and all agreed it either stopped or limited further development of granddaughter tubers. Some growers felt they applied the spray too late, and crops which were under stress may have suffered negatively. Scab is a problem in areas this year.

Potato yield dig

Teagasc potato and tillage adviser Shane Kennedy gave growers a demonstration on field yield digs. Estimating crop yields is important when planning harvest logistics as well as box and storage requirements. A yield dig also helps to identify crops with a problem, or a particular skin disease, which may get worse with late harvesting. This can help prioritise the order of fields for harvest.

Pat Farrell, IFA grain and potato executive, set out the market situation facing Ireland and Europe. Irish potato area is down around 12% on last year.

There is an area reduction of 12% in Rooster, 20-25% in Kerr’s Pink, 20% in Queens, 20% in Golden Wonders, 20% in chipping varieties, 12% in white potatoes and 4-5% in salad area. Secondary growth had proved to be a particular issue in Golden Wonders and Kerr’s Pink. Lower area and reduced yields could culminate in a reduction of 150,000t of potatoes brought to market this year. In 2012, the last comparable year in terms of price, there was an additional 1,000ha of potatoes grown in the country.

This pressure is being felt across Europe, with Germany likely to see a reduction of 40% in output this year while Poland could see a reduction of 20-30%. All signs point towards potato markets tightening and prices holding.

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Watch: conducting a yield assessment in a potato crop