Blackcurrants prefer a rather heavy moisture-holding loam. Gooseberries and redcurrants will thrive in most soils well-supplied with potash. Raspberries appreciate deep soils, well-drained and well-supplied with organic matter that will not dry out in dry weather.
Blackcurrants require plenty of nitrogen to enable them to make adequate fruiting wood each season. In fact moisture and nitrogen can be said to be the chief requirements of blackcurrants. Some potash is necessary also, and phosphates, say one year in three. Sulphate of ammonia at about 60 g/sq.m, gives good results, especially when used in conjunction with moderate dressings of dung.
Gooseberries must have adequate supplies of potash if they are to thrive, and none of the hardy fruits is so susceptible to potash deficiency as gooseberries. Sulphate of potash is the best form to use, and 20 g/sq.m is sufficient for a normal dressing, but 40 g/sq.m may be necessary in the case of a deficiency. ..A mulch of.. dung during winter is beneficial to both gooseberries and redcurrants.
These appreciate organic manures to a marked degree, especially when applied in the form of mulches. A mulching of well-rotted stable manure will give excellent results on most soils. Potash will be necessary on very light sandy soils, and sulphate of potash is the best form to use. Recent work at Mylnefield has shown that raspberries benefit from fairly high nitrogen dressings, up to 70 g/sq.m sulphate of ammonia annually.
PRUNING BUSH FRUITS
Redcurrants and gooseberries
Redcurrants are usually spur pruned,back the laterals to c.60 mm. This builds up a permanent branch framework at the top of a leg or tree trunk, helping to keep the fruit off the ground. Gooseberries for dessert may also be spur pruned by retaining a framework of branches and spurring back the laterals to 100 mm. This results in large fruit. Some of the leading growths are left to furnish new branches. A lighter system of can be adopted with gooseberries to leave some laterals unpruned or only shortened, to give more fruit, smaller .in. size… Winter . of gooseberries is often delayed until late winter if birds are known to peck out buds. The more usual method of pruning culinary gooseberries is by thinning out a few of the oldest branches and reducing the laterals so that it is possible to pick the fruit reasonably. Though usually grown on a leg where ‘dieback’ (botrytis cinerea) is serious, culinary gooseberries are often grown as a stool.
These bushes are grown on stools. They produce their fruit on the previous summer’s growth, so every endeavour should be made to encourage the growth of new wood, especially from the base. This can be achieved by drasticout of the old wood after fruiting, and by heavy manuring with nitrogenous manures. They may be continually mulched with straw or other material. As much of the old wood as possible is cut out and the young wood left. This is only feasible when the bushes are growing well and there is ample strong new wood available as replacements. The amount of old wood to be removed can vary with established bushes, but is often about a third to a half of all the shoots. Cut close to ground level where possible to encourage new growth from the stool.
Students should note that modern methods of handling blackcurrants on a large commercial scale, especially the use of mechanical pickers, are likely to alter the growing and pruning systems for this crop. Some commercial growers grow their bushes as hedgerows which are cut to the ground and harvested every other year. It is essential to have irrigation and good growing conditions.
These bear their fruit on the previous summer’s growth, and therefore, the old canes should be cut out after fruiting, and the new ones tied in. In the case of autumn-fruiting raspberry varieties, the canes should be cut hard back close to the ground in early spring.
These also bear their fruit on the previous year’s wood. Loganberries are best trained so that the young replacement wood is kept separate from the fruiting wood. This reduces the incidence of the fungus disease cane spot which would otherwise be splashed into the young wood by rain.
PROPAGATION OF BUSH FRUIT
By hard woodtaken late September to early March – usually the earlier the better. It is normal good practice to dunk the prepared cutting material in a Benlate wash and to dip the bottom of the cutting in . Open sunny sites, space approx. 200 mm x 1 m depth of insertion.
Very well drained soils
approx. 150 – 200 mm long wood of that year. All basal buds retained. (Cuttings may be bundled into 25’s and heeled in from say October to March.)
Redcurrants and gooseberries
The top four buds are retained and the others carefully cut out to reduce the incidence of sucker growth.
Later, after the nursery year, the rooted plants may be lined out and planted less deeply with the 150 mm (6 inch) leg lifting the branches well off the ground.
These are grown by planting out suckers or spawn.
Loganberries and blackberries
These are propagated by top layers, but can be produced bybud .
Old wood fruiting
By keeping the old wood away (or below) the new wood there is less infection from leaf spot.