Crop notes April 2008

The recent high winds, wintry showers and blowing frosts must mean that Spring has arrived. April is one of the busiest months in the calendar for the arable farmer and much of the March workload will have been delayed until April, making long hours in the field inevitable for many.

A few days ago I met John Sloan who was busy making some adjustments to machinery in preparation for planting this year’s potato crop. John and his brothers farm just under 400 ha outside Hillsborough. About half of the farm is grassland which supports dairy and beef enterprises while the other half is arable, split between 90 ha of cereals, 65 ha of potatoes and 40 ha of carrots.

This Lagan valley farm benefits from the deep, sandy loam which is a characteristic of the area and means there are few restrictions on what crops can be grown. But it is getting the early potato variety Accord, planted, that preoccupies John at the moment, as an earlier planted crop will mean earlier lifting, in better ground conditions.

He said that this year’s crop will be much more expensive to grow as fertiliser, diesel and spray costs are all up significantly. More competition for “clean land” has also pushed conacre prices up substantially. John hopes to offset some of the fertiliser costs by using slurry and farmyard manure on fields located near to the dairy unit. This means a potential savings of several thousand pounds from the fertiliser budget when used in conjunction with soil analyses.

There are seven potato varieties grown by the Sloans, with most of the acreage being Saxon, Maris Piper and Dunbar Standards. These varieties suit the soils around the farm and are all marketed through the family owned packing plant to outlets around the country. John reckons that a high quality crop arises from attention to detail which is why he is meticulous when obtaining seed. This comes from N.Ireland and Scotland and has been pre-treated with a fungicidal dressing to improve the skin finish of the resulting crop, now considered essential for washed and pre-packed potatoes. Careful calculation of plant spacing, blight control and harvesting dates are also critical factors that John and his brothers will take into account as the year progresses.

Most of us involved in growing cereals agree that early sowing (if soil conditions allow) is a major factor in maximising yields and therefore profitability of spring barley. We should complete spring barley sowing as soon as possible using seed rates between 160 KG/ha (10.2 stone/ acre) and 180 kg/ha (11 stone/ acre). As crops begin to emerge look out for signs of leatherjacket damage, especially in crops following grass or grassy stubbles. If a problem is suspected, treat the crop with chlorpyrifos (for example, Dursban).

Growth stage 31 (first node detectable) is the best time to apply the main nitrogen top dressing in winter cereals. However, the mild, wet weather means that many winter barley crops have passed this stage, so, applying this top-dressing without delay is essential to maintain yields.

All cereals, especially those on light, sandy or free-draining soils, will be at risk from sulphur deficiency so they should receive 15 - 25 KG S/ ha in spring. This can be done most conveniently by applying a sulphur-containing nitrogen fertiliser.

Broad-leaved weeds, especially cleavers, can still be easily controlled and will need attention as soon as possible. The range of cleaver herbicides has expanded in recent years. Where conditions are warm and weeds are actively growing, Starane will provide effective control. In colder weather, or where a wider weed control spectrum is required, alternatives (for example, Boxer, Chekker, Eagle, Lotus or Starane XL) should be considered.