Cabbage diseases and pests

Fusarium wilt – Fusarium oxysporum
Infections: infection prefers high temperature (optimal 27-28 ° C), high soil moisture and pH 5-5.6. Pests caused by roots, during transplantation, nematodes or other pests, are the gates of infection. Symptoms: In plants infected with Fusarium Oxysporum, gradual (rarely severe) wilt occurs, which usually occurs during the flowering or fruiting phase. With a sharp wilting, in conditions of high temperatures, the plants die within a few days, drying out without losing their green color. Generally, wilting phenomenon lasts 1-2 months, affected plants freeze in growth, turn yellow, wilt and dry, and then covered in wet weather with white mold. In advanced plants, manifestations may begin with the opening of the first flowers. At first there was a yellowing of the basal leaves, followed by a slow wilting, at first reversible (plants recover during the night and on cold days), then permanent. As a result, the fruits remain small and ripen early or do not reach maturity, and the seeds inside the fruit are brown or yellow. The woody vessels inside the stems and petioles are brown. Prevention – the most important stage in controlling this disease are preventive measures: planting resistant hybrids, disinfecting the soil, collecting and destroying the remains of infected plants, etc. Permanent use of chemical fertilizers, which leads to acidification of the soil (ammonium nitrate, superphosphate, etc.) should be avoided.

Buha verzei – Mamestra brassicae L.

Description – Cabbage owl two generations a year and wintering in the breech stage at a depth of 5-12 cm in the soil. Butterflies appear in late May or June and have a nocturnal flight. The eggs are laid in groups, often 10-40, on the underside of the cruciferous leaves. A female can lay an average of 600-800 eggs. After two weeks, larvae appear that feed on leaves, especially at night. The second generation appears in July and develops mainly on late cabbage or other crosses, until September. The method of damage – when they appear, the larvae bite the lower layer of the epidermis and the pulp of the leaves, and then puncture the leaf in the form of irregular holes. Caterpillars of the latter age bear irregular galleries in the heads of cabbage. Heads that have been attacked rot, both due to the attack and due to the faeces of the larvae, which helps the development of many molds. Karate Zeon can be used to combat this pest. Karate Zeon is a contact insecticide that, in addition to its rapid and shock-absorbing effect against pests, provides the longest protection period thanks to Zeon technology. The composition contained in Zeon capsules allows an amount of insecticide to reach the plant, without losing the atmosphere when applied. The gradual release of the insecticide from the capsules determines the formation of persistent deposits on the surface of the plant, resistant to the influence of ultraviolet radiation and precipitation. In cabbage cultivation, Karate Zeon was used to control white butterfly (Pieris brassicae), gray lice (Brevicoryne brassicae) and cabbage owl (Mamestra brassicae), at a dose of 0.015% (0.09 L/ha for white butterfly and 0.075 L/ha for cabbage) and a 7-day cutoff. Application recommendations – Treatments are carried out on warning, depending on the biology of each pest. In order to ensure the best possible effect, it is recommended to cover the treated crops as evenly as possible. Avoid use at high temperatures during the day, when pests are less susceptible and photolysis is severe. The maximum number of recommended treatments per season is 3. It is also recommended to alternate with products from other chemical groups, such as Actara 25 WG.

White cabbage butterfly – Pieris brassicae brassicae L.
Description – this species has 2-3 generations per year, and winters in the breech stage on logs, trees and shrubs, on fences, on the walls of houses, etc. Butterflies appear in spring, late April or May. The flight of butterflies is spread over a period of 2-25 days. Eggs are laid on the underside of cabbage leaves and on other crosses that are planted or spontaneously, in groups of 15 to 20. The female lays 200-300 eggs. The method of damage – in the early ages, the larvae bear fruit on the lower layer of the epidermis and the pulp of the leaves. From the age of three the larvae spread on all the leaves they bear, especially on the edges. In large attacks, only thicker veins remain from the leaves. It also indirectly harms cabbage rot due to the feces that accumulate between its leaves. For the fight, you can use the products: Affirm or Karate Zeon. Affirm is a relatively new insecticide, derived from nature, that fights a large number of Lepidoptera (larvae, worms, mites, etc.) of vegetable cultivation. The product is systemically topical or penetrating, with a rapid “shock” effect on the target insects, and acts by contact and ingestion. Confirmed rainproof, and through its dual action style it provides long lasting protection. Affirm is an environmentally selective product, fauna is a beneficial insect and has a very favorable residue profile, below the detection limit. For field grown cabbage, Affirm guarantees control of the following pests: white cabbage moth (Peris brassicae) and cabbage moth (Plutella maculipennis), using a dose of 1.5 kg/ha, resting time (minimum time period from application last treatment until harvest) 3 days . It should be noted that treatments start when the larvae hatch or when they first appear on the farm. Application recommendations – the product is applied before the larvae hatch in the egg, when the first larvae appear or when the maximum flight curve is recorded, the moment is determined by pheromone traps, or at a warning. For best results, it is recommended to mix with one of the following adjuvants: mineral oil, at a dosage of 0.25% (250 ml / 100 liters of water) or with organic silicon adjuvants (example: Silwet), at the dosage recommended by the manufacturer. It is recommended not to exceed three treatments per season with Afirm. The interval between applications is 7-14 days, depending on the crop, climatic conditions and pest pressure.

Gray cabbage louse – Brevicoryne brassicae L.

Description – Gray louse is a non-migratory species that grows on plants of the Cruciferae family. 16-18 generations can succeed in a year. The generation lasts on average from 10 to 14 days, but the generations in spring and autumn develop slower, which can last between 15 and 30 days, due to the cold weather. The optimum temperatures for the growth of the gray louse are between 18 and 26 degrees Celsius. It is winter in the egg phase, which the females lay in the fall, on the stems and leaf petioles of cabbage and other cultivated or sapling cruciferous plants. Damage – Planting and spontaneous Crusaders attacks from late March or early April through late autumn, with heavy damage to cabbage and cauliflower. In the years of invasion, adults and larvae form huge colonies, sometimes completely covering the leaves and shoots from which they suck the cell juice. After the attack, pale yellow or pink spots appear on the leaves. The fight can be carried out with the help of the following products: Actara or Karate Zeon. Aktara is a long-acting systemic insecticide that controls a wide range of pests in a large number of crops. It works by contact and ingestion. The product quickly enters the plant and is then carried upward (acropetal) through the vascular system, protecting the entire plant and new growth. Pests are controlled in both the larval and adult stages. For the field-grown cabbage crop, it guarantees the control of the following pests: green bed bugs (Eurytoma omatum) and gray lice (Brevicoryne brassicae), at a dose of 0.02% (0.12 kg / ha), with a time break of 7 days. Application recommendations: Treatments are carried out on warning, depending on the biology of each pest, or when the first pests appear in the culture. The maximum number of recommended foliar treatments per season is 2-3. It is recommended to alternate with phytosanitary products of other chemical groups (eg Karate Zeon).

Red cabbage bed bug – Euryderma omatum L.
Description: Red cabbage bed bugs form from one to two generations per year, depending on the region. It’s winter as an adult in the forest of foliage and under plant debris in the field. The emergence of adults occurs in early spring, sometimes in March. In the first days it feeds on various spontaneous cruciferous plants, and then transfers cultivated plants (seedlings or seedlings of broccoli, cauliflower, etc.). Method of damage: adult bites and larvae suck the cytosol from tissues. Pale yellow spots appear in the affected areas, near which the tissues dry out. In seedlings that have been attacked, the flowers are aborted and the seeds are dried. The Aktara product can be used for control.

Victor Vătămanu

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