We all love grapes. Diseases and treatment, tips on how and how to treat will help growers to maintain crops, reduce losses. The purpose of this article is to help gardeners correctly recognize grape diseases at the very beginning and learn how to deal with them. Indeed, a quick, accurate identification of diseases is the key to preventing serious yield losses. Why do grape diseases appear? What dangerous diseases can grapes have? There are many, but not all are inevitable and terrible. Timely undertaken methods and means of struggle will help to insure themselves against their occurrence. The severity of grape diseases changes every year, depending primarily on weather conditions and the susceptibility of the vine. This means that the disease can lead to devastating consequences in one year and insignificant in the next. Therefore, the measures that are taken to prevent crop losses may vary each season. How to treat grapes than to process?
In the fight against pests and diseases of grapes, a significant number of drugs are allowed to be used. Often, excessive enthusiasm for some of them leads to a loss of sensitivity of pests to the means of protection used and inhibition of the growth processes of the plant itself.
Diseases of grapes on leaves and vine, when and how to inspect a bush to identify diseases
In order to economically and environmentally soundly carry out protective measures, it is necessary first of all to conduct a phytosanitary inspection of the plantings, taking into account the phases of development of the grape bush.
The first examination is carried out during the period of kidney swelling. The second - when 2-5 leaves appear on the green shoot. And later - before flowering. Examination should begin in early spring, especially in non-covering vineyards.
If the site consists of several grape bushes, then each plant is examined. The maximum manifestation of the identified types of pests is determined, and the first 1-2 pesticide treatments are carried out on the entire site in accordance with the survey results. In the future, if possible, an individual approach to each variety is carried out taking into account its susceptibility to specific pests.
In the vineyards of farmers and specialized farms, not only each variety is subject to inspection, but all areas that differ in location and timing of protective measures in the previous growing season. Large massifs on the plain usually run diagonally and examine 5-10% of the bushes. In areas located on slopes, near forest belts or ponds, it is imperative to examine the stands at the upper and lower points, in well-ventilated and non-blown places. At each site, the minimum and maximum manifestations of diseases and the number of pests are recorded.
The first early spring inspection of vines is carried out on the following objects: bacterial cancer, bacterial wilting, anthracnose (black spotting) and oidium.
Grape diseases, description with photos
Bacterial cancer on grapes
This disease is most often found on the stem, less often on the fruit links. On the stem of the vine and the sleeves there are longitudinal cracks, and tumors are clearly visible in them. The swelling surface is uneven, tuberous, with small cracks. The lesion sites can be from 10 to 30 cm long. Most often, the swellings are located closer to the ground, sometimes huge bursts of stumps form. Such tumors die in the spring, dry out, and they can easily be separated from the bush.
If bloating rings the stem, then such a bush will die in the next 2-3 years. Bushes located at a distance of 3-5 meters from the affected should be attributed to patients with bacterial cancer, even if there are no external signs of the manifestation of the disease.
Bacterial wilt: quarantine disease
On a perennial and annual vine, longitudinal cracks appear without a tumor.
The lower eyes on the vine are underdeveloped or died. Symptoms of bacterial wilting are more pronounced at the beginning of the growing season in years with a cold and wet spring.
On diseased bushes, buds do not develop at the base of the annual shoot. At the ends of the vines, later awakening of the buds takes place and weakened green shoots develop with shortened internodes and small chlorotic leaves. Longitudinal black spots form on the petioles of leaves. Part of the shoots, reaching a length of 10-15 cm, begins to dry out.
Drying spreads from the bottom up, reddish-brown cracks form, starting from the second or third internodes. This leads to brittle shoots. The tips of the leaves acquire a reddish-brown color, and with high air humidity, a light yellow bacterial exudate appears on them. During this period, the greatest likelihood of infection of healthy bushes from patients.
Anthracnose or black spotted grape
This disease manifests itself on an annual vine with sunken spots (ulcers) with a dark (brown, dark purple, black) border in the form of a roller. Sometimes in wounds, bundles of conducting vessels are clearly visible. Heavily struck shoots seem to be burned. And with deep wounds around the roller, the shoot discolors. Anthracnose is a serious disease of cultivated and wild grape varieties. It manifests itself most destructively in warm, humid seasons.
If brown-black spots on the leaves grow, become gray, bulging or red borders appear, then your vines are infected with black spots, also known as anthracnose. Called by the fungus Elsinoe ampelina. The disease also leads to the formation of dark spots on the stems and berries.
Black rot: fungal disease
Black spots on the vine can also be a symptom of a fungal infection, which is commonly called black rot. Called by the fungus Guignardia bidwellii. As the disease progresses, small black dots turn into spots. Tiny dark blotches are fungal growths. And large ones are areas of dying plant tissue that eventually turn into holes.
Oidium or powdery mildew on grapes
Another name for this disease is powdery mildew. Fungal disease - pathogen - a fungus of the form Vitis. On the annual vine, a light whitish film first appears, which over time begins to look like brown spots of various configurations. Mushroom spores tend to spread rapidly in moist, cool conditions.
How to process grapes from diseases
After the examination, they plan to conduct the first (one or two) sprayings of grapes against a complex of diseases. If the vine is pure, characteristic of the color variety, there are no tumors and the death of the eyes is insignificant (5-15%), such plantings are not sprayed until the third or fifth leaf appears on the shoot.
If the vineyards are affected by anthracnose, it is advisable to carry out the first fungicide treatment during the period of kidney swelling. For this, 0.5-0.7% Abiga-Peak, 1-3% Bordeaux liquid, 0.2% Polyram can be used from the number of contact preparations; from the number of system-contact ones - 0.3-0.4% Mikal, 0.25% - Ridomil Gold, 0.2% Ordan.
In vineyards affected by bacterial cancer or bacterial necrosis, copper-containing fungicides should be preferred (Abiga Peak, Bordeaux liquid, Kuproksat, Ordan, Tsikhom). In addition, during the sap flow, it is not recommended to trim the bushes. And in the growing season should limit the excessive use of nitrogen fertilizers.
In vineyards heavily affected by oidium, it is advisable to carry out the first treatment in a phase of 1-3 leaves on the shoot with one of the preparations: 0.03% Topaz, 0.02% Strobi, 0.4-0.5% Tiovit Jet or Cumulus.
In vineyards affected by anthracnose and oidium, the best treatment option for swollen buds is 0.3-0.4% Mikal, in a phase of 2-5 leaves. This is a mixture of two drugs to simultaneously control oidium and anthracnose.
In vineyards oppressed by the root form of phylloxera, along with protection from seasonal diseases, a set of measures against root rot is required.
In personal subsidiary plots on grapes from the mentioned fungicides Abiga-Peak, Kuprikol, Kumulus, Tiovit Jet and Topaz are allowed.
We hope that our information will help you learn to recognize grape diseases, photos and a description of the diseases are presented in the article.
Video about grape diseases: