Spud seed hygiene scores
Spud seed hygiene scores
Perfect potato seed, treated
accurately and stored with
care – that is the starting
point for ware crop success
on one East Anglian farm.
Charles Abel reports
POTATOES are a key crop for Lincs farm manager Nigel Patrick.
With premium pre-pack markets the goal pristine seed is essential to cut skin blemishes to the absolute minimum.
Even slight skin finish defects can slash pre-pack values in half. "We have got to produce the best quality and that means paying careful attention to seed health right from the outset," he says.
To boost store hygiene and improve the accuracy of seed treatment Mr Patrick started using Banks Agricultures Specialist Potato Service last season.
Judging in-field benefits between different seasons is not easy, but Mr Patrick is adamant the changes made have brought a big step forward. "You could see the old system was not giving us full seed treatment coverage. I would say the new system we are operating has improved chemical coverage by 50%."
Control of seed quality is taken early on 800ha (2000 acres)
Lundys Farm which Mr Patrick manages for Hay Farming near Holbeach. SE1 stock being brought in from Scotland for multiplication on reclaimed PCN-free land near the Wash.
Disease levels can be monitored and seed acclimatised to south Lincs conditions, giving more control over stem number and maturity the following season, Mr Patrick notes.
Hygiene is paramount. For each 5t lot of SE1 received 150kg (3cwt) is washed and checked for infection. Once grown the seed is lifted as early as possible in August direct into 1t boxes, once target seed size and count has been reached. That minimises both blackleg and soil loading.
A drying wall designed for daffodils dries the seed. Any excess soil falls off easily during grading and treating in the winter, improving fungicide coverage.
Rigorous store cleaning is now followed by contract fogging with Jet 5 disinfectant in both the 200t chitting and 2200t ware store. Equipment is cleaned regularly and dust and dirt levels minimised.
All commercial seed is now treated with one of Banks Agricultures mobile seed treatment units, replacing the farms old roller table and Team sprayer.
The mobile units give the highest levels of fungicide coverage available, Banks claims. Flow rate can be controlled throughout the machine to keep the roller table full, smaller rollers improve rotation of small seed and an infra-red tuber counter allows count per tray to be pre-set.
"We aim for 190 tubers over 25mm per tray, according to variety, to give the optimum planting density in spring."
Slower throughput, typically 4t/hour, means counting is generally more accurate than seed suppliers running equipment at faster workrates, says Banks Clare Barker. "Some growers have found those are less accurate than they might be." Split grading is also possible.
Monceren IM Flowable (pencycuron + imazalil) gives good control of silver and black scurf, the main problems on the farm, with application before dormancy break avoiding any knock to field emergence. Inclusion of Admix P, a wetter cleared for use on potato seed, bulbs and corms, improves chemical coverage, says Miss Barker.
Costs are from £4/t for hiring the mobile unit and as little as 40p/t for Jet 5 fogging. "Against the costs of growing potatoes it is not a lot," says Mr Patrick.
He may now specify untreated SE1 seed next year and use the treater to apply fungicide himself. "Every time seed gets handled during transit it loses a little more of the treatment, so treating on the farm makes good sense." *
HAY FARMING
• 800ha near Holbeach, Lincs.
• Silt land, some reclaimed.
• Potatoes, sugar beet, onions, daffodils, vining peas, wheat.
• 80ha Cara, Piper, Squire, Fianna for premium pre-pack.
• Some stored to May.
QUALITY CONTROL
• Scottish SE1 checked on arrival.
• Multiplied on clean land.
• Stores Jet 5 fogged.
• Mobile seed treatment unit.
• Wetter aids coverage.
• Strict store hygiene.
No weak links in specialist system
Seed hygiene must be a continuous process from seed source to planting, with no weak links in the chain, says Paul Overton, technical co-ordinator of Banks Agricultures Specialist Potato Services division.
"Too many farms are just not putting enough value on hygiene once seed arrives on the farm. We see it time and again. It may cost management time, but growers must pay due respect to seed hygiene.
"What Patrick is doing is taking control of his own seed production. It is seed improvement, rather than farm saving. He runs a slightly higher risk of virus, which can be controlled, but minimises the risks of blackleg and makes a cost saving too. But to make it work he does need good store hygiene to protect the quality of the seed."
On-farm hygiene should start with specifying the right seed, checking it is of good quality on arrival and then storing it well. That means disinfecting stores and equipment. "You should aim to hit fungal spores any time you can," he urges.
Before using a store remove as much dust and debris as possible, vacuum rather than sweep to avoid further dust, then disinfect, with boxes and trays in the store. Clean equipment between batches, remove soil build-up daily and vacuum floors daily, especially along forklift paths.
Having evaluated other disinfectants Banks now uses Jet 5 fogging routinely. "We would also advise disinfecting seed treatment equipment between variety batches using a knapsack sprayer. It makes sense to treat the planter too. SAC work shows machinery can be a major way of spreading infection."
The company runs five mobile seed treatment units, as well as offering expert advice and contract disinfection of stores. Modifications to improve spray deposition include a slight downdraft and powered reverse-rotating rollers to ensure the whole tuber is exposed to spray.