Sea buckthorn - treatments, pest and disease control

Sea buckthorn (Hippophae rhamnoides) is a fruit-bearing shrub, widespread in hilly and mountainous areas. Sea buckthorn fruits contain minerals and vitamins in considerable quantities, and for this reason, it is cultivated in many regions. It grows in the form of a 1-1.5 m high bush and it has high light demands, being cultivated only on well-lit fields. It is very resistant to biotic factors, being slightly affected by diseases and pests

The main diseases of sea buckthorn shrubs

**Verticillium wilt (Verticillium sp.)**

This disease is present in the areas where sea buckthorn is cultivated and occurs mainly in plantations aged between 5 and 8 years. The first symptoms are yellowing and gradual wilting of the leaves. The fruits ripen prematurely and dry. After the attack, the plants wilt during the day and look normal in the evening. Also, red bumps appear on the shrub bark. If you make a section in the stem, you can see the tissues turning brown. Infected shrubs wither after a 1-2 year period since the first symptoms appeared.

Prevention and control measures:

if the disease is at an advanced stage, the shrubs must be removed from the plantation and burned.

Fusarium sp.

It produces symptoms similar to those produced by Verticillium. The disease initially causes vein discoloration, followed by petiole wilting. These symptoms can be seen initially on a few leaves, and eventually in the whole bush. If you make a section in the stem, you can see the tissues turning brown. Eventually, the plant withers irreversibly.

Prevention and control measures:

removing and burning the unhealthy shrubs, if the disease is in an advanced stage.

Rust (Puccinia sp.)

The first symptoms of this disease include chlorotic spots on the upper part of the leaves. The disease progresses and on the underside orange pustules appear, representing the fungus fructifications. These lead to severe leaf deformation.

The main pests of sea buckthorn shrubs

Aphids

They are polyphagous species that migrate from one plant to another or from one species to another. Aphids grow on wild flora and then move to cultivated species. The attack occurs as a colony on the underside of leaves, on flowers or inflorescences, and young shoots. The insects feed on plant sap, causing stress to the plant. In case of a severe attack, aphids lead to plant death.

The San Jose scale (Quadraspidiotus perniciosus)

It is a polyphagous species that attacks over 200 plant species. It has 1-3 generations per year and overwinters as larvae on the bark of affected species. Females and larvae spread to all organs of affected plants, including fruit, and feed on plant sap. In a massive attack, the shields protecting the insect bodies overlap and suffocate the shrubs. They stagnate in growth, and after 2-3 years they wither.

**Buffalo treehopper (Cerasa bubalus)**

It is a species that causes indirect damage to shrubs. It develops one generation per year and overwinters as an egg in cracks in the bark of shrubs. This treehopper feeds on the sap of herbaceous plants (clover, alfalfa, etc.). The females lay their eggs on the shrub branches in an incision made with the ovipositor. The bark cracks in the affected area and sap flow is stopped. Attacked branches no longer bear fruit normally, and dry up when attacked severely. Also, the wounds produced are entry points for plant pathogens. The greatest damage is to young plants, which wither after the attack.

Control measures:

Controlling this insect is difficult and requires preventive methods:

inspecting the planting material carefully;
pruning and burning the affected branches;
weed control;
chemical treatments during the dormant period with a horticultural oil.

**The gypsy moth (Lymantria dispar)**

It is a dangerous species that causes massive defoliation of trees and fruit species. It hibernates as an egg in a silky shelter created on the bark of attacked species. In spring the larvae emerge and move on the leaves, causing defoliation.

Citrus flatid planthopper (Metcalfa pruinosa)

It is a polyphagous species that attacks vines, ornamental trees and shrubs, and fruit trees/shrubs. It develops one generation per year and overwinters in the egg stage in the branches of attacked plants. Adults and larvae feed on the plant sap, preventing plant growth and spreading numerous viruses. Fighting this species is very difficult due to the wax layer covering the insect’s body. For this reason, the planthopper can quite easily be confused with the woolly apple aphid (Eriosoma lanigerum).

Mites

They are insects that are very difficult to see with the naked eye. Aphids are polyphagous species that attack many plants and fruit trees, both cultivated and wild species. They feed on the plant’s sap and after the attack the leaves look parchment-like, the flowers abort and the plant stagnates in growth.

Common cockchafer (Melolontha melolontha)

This insect is particularly dangerous. It develops a generation every 3 to 4 years and overwinters as larvae of various ages in the soil. During the development period, the larvae feed on the underground parts of various plants and the attack leads to bush wilting.

Control measures:

mobilizing the soil around the bush;
specific insecticide treatments.

Nematodes

Nematodes overwinter as adults inside affected plants and in the soil. They migrate with the help of water in the soil and live inside the affected plants, feeding on the plant’s sap. The flowers of attacked plants remain undeveloped or even deform.