Black Currant Pruning. Diseases Of Black Currant

2024 Author: Sebastian Paterson | [email protected]. Last modified: 2023-12-16 13:47

Vitamin champion. Part 2

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Black currant pruning

All pruning is best done in spring or at the very beginning of summer, but not in August or early September, because with early autumn pruning, young shoots will grow at the ends of the branches, which will die in winter. With late autumn pruning in November, frostbite of wood may occur through the wounds. And in fact, and in another case, the ends of the branches will have to be cut again next spring.

Why do double work? If the branches grow inside the bush, then they only thicken the bush, but do not bear fruit, therefore, they should be cut out. If the branches cross, then one of them should also be cut. If root shoots do not grow, then it is necessary to make a strong pruning of several branches, shortening them by about a third of the length. If such a shortening pruning did not help, the balance between the aerial part and the roots should be disturbed by cutting one or two weak branches to the ground. The roots will turn out to be more powerful than the aboveground part and, in order to restore balance, they will immediately push a new root shoot out of the soil.

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An adult blackcurrant bush (which is 5-6 years old) should have about 12-15 shoots of different ages. How can this be achieved? Regular (annual) cutting of obsolete stems. As soon as you cut the old stem to the base, without leaving a hemp, a new root shoot appears from the soil, which must be shortened next spring, leaving only three or four buds above the ground. If too many root suckers appear, then no more than two should be left annually, the rest should be removed.

The main indicator for pruning is the growth of the current year. If it is weak and small (about 10 cm), then you need to go down the branch to the place where there are a lot of fruits or a strong top grows (it always appears if things are not going well in the upper part of the branch) and cut off the upper part of the branch to this place … Black currant bears fruit mainly on the growths of the previous year. They are clearly visible, they are lighter than the rest of the branches.

How to distinguish an old stem from a young one? First, it has an old gray bark. Secondly, there are practically no berries on the old shoot. This is clearly visible in the spring, since there are no flower brushes on the old shoots. There are rings on the branches - indicators of the number of years. Branches older than 5-6 years must be removed annually, otherwise the yields fall.

How to rejuvenate an old bush?

If the bush is more than 20-25 years old, then it must be uprooted and burned, no rejuvenation will help. If the bush is about 15-17 years old, then first you need to cut about a third of the stems to the very base. Of the replacement shoots that appear, the three strongest should be left, the rest should be cut out. Then next year it is necessary to cut out another third of the old branches and again leave no more than three new shoots of replacement. And only in the third year, remove all other old stems. It is undesirable to cut off the entire bush at once, although it is possible.

If frail basal shoots grow in the center of the bush, then they should be cut immediately without leaving hemp. Weak thin branches must also be removed, cutting them out to the point of attachment to a thicker branch. Now you should take a close look at this branch, or rather at its upper part. If the upper part of the stem has few fruit (small fruit branches located throughout the stem), then it must also be cut off.

The berries become smaller, therefore, the bush grows old if new basal shoots (shoots of zero order) do not appear from the ground. Strong pruning causes their appearance. After any trimming, all cut pieces must be burned immediately!

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What diseases does black currant have?

The most terrible disease is an incurable viral disease called terry. It is easy to spot during flowering. Usually, the flowers of black currant with white rounded petals, and in patients with terry bushes, the flowers are deformed, and the petals resemble the narrow tentacles of a squid of a dirty pink color extended forward. The ovary formed from them is torn apart. We must not only cut out a branch with such flowers, we must immediately uproot the entire bush and burn it. You cannot plant black currants in this place for 4-5 years. If you leave a sick bush, there is a high probability of ruining the entire plantation, since insects carry the disease with their saliva from one plant to another.

Another common disease is powdery mildew (spheroteka). It manifests itself primarily on young leaves that grow in mid-summer (in the North-West in July) in the form of a white bloom. Then it goes on to berries and old leaves, which then darken, curl and die off. This is a fungal disease. Spores of the fungus overwinter on the affected parts of the bushes. The easiest way to combat any disease is with good care. Weakened plants are mainly affected.

In the spring, on young leaves, and then two weeks later, on young ovaries, the bushes can be sprayed with one of the chemicals: vectra, topaz, colloidal sulfur, which are diluted according to the instructions or with a 0.1 percent solution of copper sulfate, Bordeaux liquid or copper oxychloride (1 teaspoon spoon for 5-7 liters of water). You can use iodine, for which one bottle of 5% iodine (10 ml) is diluted in 10 liters of water.

They make a small birch broom and "spank" the bushes from top to bottom with iodine solution. After three days, the execution is repeated (the iodine solution can stand for several days in a sealed container). Or the bushes are sprayed with a phytosporin solution. Fitosporin is not a chemical and it is not absorbed by leaves and berries, so they can be washed and eaten right after spraying. Therefore, this drug, along with iodine, is preferable to others. Spraying is carried out systematically, once a month, starting in mid-May.

If you have fresh manure, especially horse manure, then you can avoid diseases and pest attacks by simply throwing one shovel of manure from above into the center of the bush in June, in which bacteria develop that destroy the pathogens of powdery mildew.

There is another harmless old-fashioned way: regularly wash the tops of the bushes with a soap-ash solution or kefir diluted in water, or whey from yogurt. You can spray the bushes with a solution of drinking or soda ash before flowering and immediately after flowering (3 tablespoons of any of them per 10 liters of water). Since black currant leaves are poorly wetted, a little soap of any kind (40 g) should be added to the solution for better adhesion.

The disease is facilitated by the introduction of nitrogen under the bushes and watering with infusion of weeds (one shovel of manure in the center of the bush does not make the weather). The ends of the branches affected by powdery mildew are clearly visible - they turn black. They must be cut in early spring, since they died anyway, but at the same time they are a breeding ground for the spherotek. Since powdery mildew begins on young leaves at the ends of the branches, as soon as the berries begin to ripen, pinch the ends of the branches (plucking out the growth bud).

In early spring, immediately after full blooming of leaves, goblet rust, usually wintering on sedge, can move to black currant. It manifests itself as raised, orange warts. Spores ripen on the underside of the leaf, then fly further.

There is another similar disease - columnar rust, wintering on coniferous crops, mainly on pine. It appears as small yellow-orange dots on the leaves. If you do not apply any measures, then the spores of the fungus can spread throughout the entire leaf, and it will turn yellow entirely, and then fall off. Control measures are the same as for goblet rust.

In the middle of summer, red-brown spots usually appear on black currant leaves, which then merge into solid spots; leaves, starting from the bottom, turn brown and fall prematurely. This is anthracnose. The fungus that causes this disease hibernates on the remains of leaves. Therefore, immediately after the onset of the disease, they should be sprayed with phytosporin and repeated at the end of summer. Usually it is recommended to either remove the leaves or bury them in the soil under the bushes.

I just in late autumn, when the temperature drops to 8 degrees Celsius, I spray the entire garden, including black currant bushes, as well as the soil under bushes and trees, with a very high concentration of urea solution (700 g per 10 liters of water). This spraying destroys pathogens of fungal and bacterial diseases, as well as all pests wintering in the forks of branches and in fallen leaves. This spraying should be repeated in early spring, even before the sap flow begins (in the North-West in late March - early April).

Sometimes, especially on the old bark, small orange dots appear. It is a mushroom that settles on dying wood. You just have to cut out the aging branches and burn them.

It should be recalled that all spraying should be done in the evening, in calm weather without wind and rain. There should be no rain for at least three hours after spraying.

The widespread pouring boiling water over the bushes in early spring is a titanic work and completely useless.

Read the rest of the article →

Vitamin Champion:

Part 1: Planting and growing black currants

Part 2: Pruning black currants. Diseases of black currant

Part 3: Pests of black currant

Part 4: Reproduction of black currant. Black currant varieties