Potatoes - Knowledge Transfer
High yields of good quality potatoes can be produced under Irish soils and climatic conditions if the crop is well managed throughout the growing season. The crop must be carefully handled after harvest to maintain quality. Potato growers need to pay particular attention to site and crop rotation, seedbed preparation, disease control and harvesting.
Choosing a suitable field, soil-type and place in the crop rotation is an important first step to producing potatoes profitably.
Potatoes can be grown across a wide range of soil types and should not be grown more than one year in four in a rotation, otherwise potato cyst eelworm may cause a problem.Deep cultivations to produce a clod free seed bed are required.
Potatoes can be divided into three categories based on when they mature. Earlies normally mature in about three and a half months (100 days). Second earlies will take about four months (120 days) to mature. First earlies are normally sown in early February in Wexford and late February in the Northeast. Second earlies are sown from early to mid-March and maincrop are sown from mid March (mainly April) to early May.
These dates may vary depending on the weather.
Plant maincrop potatoes in March or April, when soil temperatures rise above 7oc. Plant about 10 cm deep and in general 20-25 cm apart(in 80 cm drills).
Potatoes need significant amounts of N, P, and K nutrients and in some cases additional trace elements. Use the result of a recent soil test to decide the rate of fertiliser application.
Potatoes must be protected against competition from weeds. Use a herbicide or combination of herbicides to keep weeds under control. In an organic situation stale seedbeds, manual hoeing or gas burning can be considered.
Wireworms and slugs can be a problem following grass crops. Aphids can spread virus diseases, and need to be controlled in crops from which seed is to be planted. Eelworm fields must be avoided for at least 10 years.
It is essential to prevent potato blight entering the crop. Use a mixture of cultural and chemical control methods to keep the disease at bay. Start the fungicide programme in time and don’t miss any applications.