In most cases, the leaves of that currant, which has undergone a leaf gall aphids, turn yellow. Gallic aphid - This is a small insect with a pale yellow color. The parasite settles on all types of plants.
During the season, up to 7 generations of this insect can be born. It feeds in the following way: it pierces the vessels of the leaf and sucks the juice that is useful and nutritious enough for it. After that, reddish and yellowish swellings remain on the damaged leaf, then they darken, and the leaves themselves fall completely ahead of time.
If you do not start the fight against this pest in time, then for a short time it can colonize itself and damage all plants. The fruits on the damaged currant bush become small, or do not appear at all. Affected plant should be sprayed with a special solution.
Yellow leaves currant: causes
If the leaves have turned yellow in the currant, this may not always mean that the plant has been attacked by gallic aphids. Often the leaves may turn yellow and fall off due to dry soil. To avoid this, in dry and hot weather, the bushes of plants should be regularly watered and fed, in which case it will bring a good harvest. Still, a plot of land on which the bush grows, you need to periodically loosen, fertilize and weed.
All varieties of currants are often unpretentious in growing and can adapt to almost any conditions. But you need to know that the soil for its planting should be soft so that there are no obstacles to the development and growth of the roots, as well as the production of various nutrients. Too much fertilization is not necessary; everything should be in moderation. If there is an excess of peat in the soil, the plant's root system may burn completely, and subsequently it will die.
It is necessary to plant each individual bush at a distance of about 1 m from each other. If we neglect this advice, the bushes will be small, and therefore the harvest will not be rich. If the place for planting is in the shade, then you will not have to wait for a good harvest either, because this plant loves light.
Here is list of pests that currant bushes may be affected:
- leaf gall aphid - damages the leaves, as a result of which they turn yellow, wither, roll up and fall off;
- kidney mite - plant in the plant buds, in each of them several thousand individuals can live. Subsequently, the buds dry out and do not bloom. In addition, the kidney mite spreads such a viral disease as the black currant's terry;
- spider mite - not only currant, but also other berry plants are affected. It settles on the leaves and feeds on their own. They lose color, turn yellow and dry up;
- currant gall midges - resemble small mosquitoes of a brown-yellow color. They settle in both flowers and leaves of the plant. Leaves can dry out and fall off, but in addition to them, branches that also dry out can be damaged by insects;
- kidney currant moth - small caterpillar, feeding on swollen bud buds;
- currant glass bowl - feeds on the core of young shoots, after they die;
- blackcurrant goldfish - insect larvae hibernate inside shoots of a bush, in June beetles crawl out. After the escape, it dries out and dies, while the beetles themselves destroy the leaves of the bush;
- leaf sawflies - white and red currants are affected - the insect eats their leaves, usually after the attack only the veins are left from the leaf;
- Blackcurrant berry sawfly - eats the berries themselves and develops, by the way, also inside them.
Diseases that affect currant leaves
- American powdery mildew (spherotek) - a fungal disease that affects the fruits, leaves and tops of the shoots. The affected areas are covered with a mealy bloom, the leaves twist and dry, and the resulting berries fall off altogether.
- Anthracnose is another fungal disease that damages the leaves. The red currant also damages the leaf stalks, stems and berries. The disease develops in early May, brown spots form on the leaves, then they curl and fall.
- Leaf spot - affects the leaves, the disease also belongs to the fungal. Overwinter on last year’s fallen leaves.
- Rust - tolerated by weeds of the grass family. The leaves are covered with yellow spots, and below them appear reddish-yellow swellings.
- The blackness of the black currant is a viral disease that carries its spider mite. Currant flowers are purple and terry. The leaves acquire an elongated shape, the affected bushes no longer bear fruit.
Currant Pest and Disease Control
In early spring, when the buds of the plant have not yet blossomed, first of all, it is necessary to thin the bushes and remove all the branches that were susceptible to infection with a kidney mite, a glass-case and a moth. The garden plot needs to be cleared of last year’s fallen leaves. You can still handle bushes with ordinary hot water (its temperature should reach 70 ° C).
When the buds begin to swell and before the flowering period, the plant can be treated with chemicals such as Kinmiks and Decis, which are good prevention against pests. And if the currant is sick, then you can use Bordeaux liquid, Topaz, colloidal sulfur, HOM, or hydroxy-HOM, basezol to treat it. Such treatments should be carried out regularly - once every 10 days. You can use several drugs one by one.
After the bush has blossomed, but before the berries themselves ripen, the plant is usually sprayed with an infusion of onion peel and with preparations such as Fitoverm and Agravertin to control insects. To combat diseases, you can use a decoction of wood ash (10 liters of water requires part of a bucket of ash), Bordeaux mixture or a mullein tincture (10 liters of water you need to take 1 liter fermented liquor).
After the crop is harvested, for the further control of pests and diseases, you can use the same tools that were used for the same purpose before the flowering bushes. Methods of application and the required dosage is indicated in the instructions for their use.
Yellow leaves of black currant: what to do?
The reason for this can be either pests or diseases affecting the leaves of the plant. In order to avoid this, it is necessary to follow the rules of agrotechnology, because pests are unlikely to find a place on the site that is being properly cared for.
- First of all, the bushes cannot be planted too close to each other. It is necessary to regularly prune and burn the damaged parts of the plant. The land between the beds needs to be dug up in the fall, this contributes to the destruction of the pests that overwinter there.
- If, after carrying out preventive measures to control pests and diseases, the plant is still exposed to them, then it is not necessary to immediately apply chemicals. If it is not enough harmful insects, then they can be collected independently and after to destroy.
- Solutions of insecticidal plants can be used - they do much less harm compared to chemicals. If the situation is too running, then only in this case, you can use toxic chemicals.
For currants need proper care, because just planting a plant and waiting for a rich harvest is not enough. Any plant needs treatment, only then it will thank its owner with selected fruits!