Round-the-clock lifting yields pleasant surprise
As the outcome of one of
the latest ever potato
planting seasons becomes
clearer, Andrew Blake finds
out how the crop is
performing for two of our
TWENTY-FOUR hour lifting, use of neutron probes for irrigation scheduling and lower nitrogen use seem to have paid off in the Midlands.
With two-thirds of his 146ha (360 acres) of Russet Burbank, Maris Piper and Pentland Dell for processing harvested, Steven McKendrick is well pleased with this years results. "Yields are surprisingly good," he says.
Considering that 85% of the crop at Blakenhall Park, Burton under Needwood, Staffs was not planted until May and some did not go in until the first week in June, the turnout is unexpected.
To make the most of the shorter growing season Mr McKendrick delayed lifting for two weeks until Sep 21 and introduced round-the-clock working in two shifts with the Grimme Variant harvester and windrower from Oct 1.
"We normally finish planting by the end of April. This year we started on Mar 18 and got only 24ha (60 acres) in before 10cm (4in) of rain stopped us. We had to replant 2ha (5 acres) which got flooded. We usually take six weeks to plant. This year it took 12."
Early planted and lifted Russet Burbank hit by slumped soil gave a weighbridge-checked 47t/ha (19t/acre) graded into store. "Thats about what we expect from our fairly tight rotation. But the mid-May plantings produced 22.75t/acre.
"We normally average 20t/acre on Piper. But so far we have ranged from 20.75 to 26.75 with an average of 22.5. We had some foliar blight, in places as bad as last year, but I havent seen any tuber blight yet." Spray intervals were down to five days from early July, he notes.
Soil types rule out packing markets, so skin finish is not critical, he adds. "Its generally quite good, although the Piper from the heavier land is a bit scabby."
Irrigation, possible on 70% of the area, was clearly required less this wet season. In some years up to 25cm (10in) is used on the lighter land.
Nevertheless, 10cm (4in) was needed on some of the lightest fields to prevent soil moisture deficits falling below 3cm (1.2in).
Helping to achieve this Mr McKendrick employed neutron probes for the first time on two sites, one heavy and one light. "I was a bit sceptical at first, but they have been quite useful, especially on the heavy ground where it would have been very easy to over-water. They helped us decide not to irrigate towards the end of the season. By not doing so we have avoided waterlogging which might have put us further behind."
The only other significant husbandry change this season was to reduce the amount of foliar nitrogen applied.
"Given the late start we were prepared to sacrifice yield for maturity," he explains. Normally three to five applications take total N use to 220kg/ha (176 units/acre). "This year some fields had only one or two treatments and we have probably averaged 180kg/ha."
The entire crop is stored. With much of it still coming in at 12C (54F) curing has been relatively easy. "I am particularly concerned about soft rots and gangrene so we have been going for a fast cure of about five days." Ambient cool night air has then helped get the crop down to 8C (46F).
"Working 24 hours is a bit trickier. The biggest problem is seeing where all the tractors and trailers are. But we have lifted in the dark before and we have a good team of about 24 including casuals. So far it has worked very well.
"I am pleased with the results in what has been a difficult and uncertain season."
• Yields surprisingly good.
• No tuber blight to date.
• 24-hour work extending season.
• Neutron probes helpful.