Potatoes

Potatoes
1. Importance – Grown as first earlies, second earlies or maincrop. Ireland is self sufficient and exports some seed potatoes
2. Soil Type – grow on wide range of soils but like well drained deep loams with few stones. pH 5-6.
3. Rotation – very important to control potato cyst nematode (PCN). Only grow 1 in 4 years, best after a ley.
4. Use of Fertiliser – Broadcast a compound such as 7:6:17 or 10:10:20 on seedbed before ridging. N requirement depends on previous cropping history, soil type, rainfall and variety. P and K requirement depends on soil test. Too much N gives watery spud.
5. Seed Bed Preparation – plough in autumn to a depth of 22cm, power harrow in spring to give fine deep seedbed. Stones may be removed. Place the soil in well rounded ridges 76cm apart and plant spuds in furrow.
6. Seed – use Dept. of Ag. Certified seed choosing variety depending on category of potato e.g. first early = Homeguard, second early = British Queen and maincrop = Rooster.
7. Planting – Plant spuds 10cm deep with automatic or semi-automatic planter. Space spuds 25-35cm apart depending on seed size. Seed should be sprouted prior to planting to increase yield.
8. Weed Control – earthing up reduces weeds and protects spuds from sunlight and blight spores. Also use total contact and residual herbicide when 15-20% of crop has emerged. When the haulms meet across the drills the weeds are prevented by shading.
9. Earthing Up – Carried out when crop is 20-25cm high. Furrows deepened and ridges widened. A valuable aid in weed control. Helps to prevent greening of potatoes and also reduces risk of blight spores being washed into tubers.
10. Diseases & Pests (Control) – main ones are PCN (crop rotation) and potato blight (spray systemic fungicide). Others include wireworms, slugs, aphids (insecticides) and blackleg and common scab (seed treatment).
11. Harvesting – Kill off haulms with spray 3 weeks before harvest and use elevator digger or complete potato harvester. Earlies in May/June yield 7 - 10 t/ha, maincrop in September/October yield 30 – 40 t/ha.