The productivity of currant is affected by a number of factors: availability in the soil of necessary nutrients and moisture, age of the fructifying branches and degree of illumination of plants. For this reason of measure, the amounts of the berries picked from bush directed to increase, represent complex of works on fertilizing, cutting and watering of bushes.
One of conditions of future harvest is spring pollination of flowers. In the conditions of midland the blackcurrant blossoms in the second half of May within ten-twenty days. Pollen of currant differs in stickiness and is badly transferred by wind. To involve in landings of insects pollinators the bushes spray with the solution prepared from tablespoon of honey and liter of water.
Positively affects productivity of currant and cross-pollination by pollen of other grade. That it has become possible, on the allotment intended for landing of this culture place two-three grades of currant differing on maturing terms. That at such variety not to allow shadowing of plants, versions at which bushes have the sprawling form put less often than grades with compact krone. Unlike black, self-fertile red currant does not demand for increase in harvest of cross-pollination.
Because of lack of moisture of the soil currant can dump already created ovaries. To prevent it and to increase future harvest, landings if necessary water. In droughty year after the end of blossoming of currant on square meter of the soil four buckets of water will be required. After moisture absorption the earth is mulched. The same operation is made during forming of berries. Currant consumes rather large amount of nutrients. For receiving big crops of this berry it is required to make up for loss of the connections which are taken out by plant from the earth. As show experiments, the good result can be achieved if hundred grams of the soil contain not less than thirty milligrams of phosphorus pentoxide, available to bush, and twenty five milligrams of potassium oxide. To bring the content of necessary connections in the earth to the necessary concentration, every year on square meter of the soil bring thirty grams of ammonium nitrate, eighty grams of superphosphate and twenty five grams of sulfate potassium. Ammonium nitrate of landing fertilize in the early spring when the soil differs in humidity. Other substances scatter in the furrows which are dug out along bush krone border in the fall. The main harvest of blackcurrant is concentrated on two years' or three years' escapes. Older branches give less berries, and therefore plants form by cutting so that on bush annually there were three-four one-year escapes which will gradually replace the deleted six-year branches. For red currant the productive age of escape increases up to seven years. Gradual cutting it is possible to restore productivity of the bush which was not exposed to forming. For this purpose within two-three years from currant delete all old branches. Cutting of plant is carried out, as a rule, in the fall, after leaf fall.