Barley treatments, most common diseases and pests of this cereal

barley hordeum vulgare

barley hordeum vulgare
The barley (Hordeum vulgare) is one of the first crop plants, which has been grown since the Stone Ages, when men have first started to do agriculture. Nowadays, the barley is widely spread in the equatorial and arctic areas. This plant is used both in our diet and in the animals’ diets. Barley is also used in beer manufacturing. The barley has large quantities of manganese, phosphorus, copper, magnesium, iron, zinc, potassium and it is also an important fiber source. The barley is very similar to the wheat, this is why they share a large number of diseases and pests.

Main diseases

Virosis:

Barley yellow dwarf virus:

The affected plants have a darker color and then they turn yellow. This virosis attacks the plants since their sprouting stage, causing a stop in the plant’s natural growth, followed by a lack of spike growth. If the plants are attacked during their knotting stage, they grow less knots, the tips and veins of the leaves are yellow. The affected plants grow some spikes, with a large number of sterile spikes. This virus is transmitted by aphids.
barley hordeum vulgare Barley yellow dwarf virus
Prevention and control measures:

  • Destroying the weeds from the crops;
  • Performing specific soil maintenance;
  • Sowing during the correct time;
  • Applying pesticides against acari;
  • Planting resilient species;

Barley stripe mosaic virus:

The infected seeds grow plants which are slightly yellow. As the virus evolves, the leaves have yellow or gray stripes. The plant has a mosaic aspect. In the first stage of the spikes’ growing process, the leaf spots turn brown and the affected tissues die. The affected plants grow small and sterile spikes. This virus is transmitted through the infected seeds.
barley hordeum vulgare Barley stripe mosaic virus
Prevention and control measures:

  • Destroying the spontaneous plants (Poaceae family) from the crop;
  • Performing the needed soil maintenance;
  • Plating resilient species;
  • Using certified seeds, which have been obtained from a reliable source;

Mycosis:

Powdery Mildew, caused by Erysiphe graminis:

This disease is visible since spring. On the base leaves and on the stems white, felt looking like spots appear. The spots become dusty and circular formations arise, which represent the fungus’ fruition. The attack can rapidly extend and it can affect even the spikes. The affected tissues become yellow and wilted. The leaves prematurely become dried out, the spikes no longer grow as they should and the plant grows frail seeds. the fungus spends the winter on the vegetal residues from the surface of the soil. The moisty autumn weather can cause autumn infections. This disease is favored by excessive nitrogen fertilizing, lack of crop rotation or sowing high densities.
barley-hordeum-vulgare-Erysiphe-graminis
Prevention and control measures:

  • Burying the vegetal residues by ploughing;
  • Destroying the weeds;
  • Balanced fertilization;
  • Plating resilient species;
  • Applying 1-2 treatments during the phenophase, using Bumper, Topas, Kumulus, Mirage, Zamir;

Barley Stripe, caused by Pyrenophora graminea:

The first symptoms are visible since April. Bleached stripes can be seen on the leaves, stripes which are parallel with the main vein. Slowly, the stripes turn brown, the affected tissues become dry and covered by a gray fluff. On this fluff, black to brown, circular formations appear, which represent the fungus’ fruition. The dried-out tissues break from the tip to the base, making the leaves looking torn apart. The affected plants are under-developed, the spikes are deformed and grow thin, solid and brown seeds. these seeds will carry the disease further. This disease is transmitted through the infected seeds and through the vegetal residues from the surface of the soil.
barley hordeum vulgare Pyrenophora graminea
Prevention and control measures:

  • Respecting an optimum density;
  • Destroying the weeds;
  • Correct crop rotation;
  • Balanced fertilizing;
  • Using certified seeds, which were obtained from a reliable source;
  • Chemical treatments, using: Nativo, Mystic, Amistar Xtra, Menara;

Spot Blotch Disease, caused by Pyrenophora teres:

The main symptoms of this disease are visible on the leaves. Yellow, circular spots grow on the leaves. As the disease evolves, the spots grow bigger. On the surface of these spots, brown stripes can be seen. These stripes grow, the spots turn brown and become covered by a silky fluff. After the attack, the leaves turn yellow and wilt. If the conditions are favorable, the disease can also affect the spikes. They grow frail seeds, of a yellow-brown color, which will carry the infection. The disease can also live on the vegetal residues from the surface of the soil, causing infections in the year to come.
barley hordeum vulgare Pyrenophora teres
Prevention and control measures:

  • Respecting the optimum density;
  • Destroying the weeds;
  • Correct crop rotation;
  • Balanced fertilizing;
  • Using certified seeds, which come from a reliable source;
  • Using products to prevent the Barley Stripes are useful against this disease too;

Loose Smut of Barley, caused by Ustilago nuda:

The affected plants grow a premature spike. The spike components are destroyed and replaced by a black spore mass. These get carried by the wind and land on the healthy plants or remain on the soil. All that remains from the spike is the central ax.
barley hordeum vulgare Ustilago nuda
Prevention and control measures:

  • Plating resilient species;
  • Correct crop rotation;
  • Treating the seeds before sowing represents the main prevention method. Products to be used: Vitavax, Dividend Star , Kinto Duo;

False Loose Smut, caused by Ustilago nigra:

This disease is widely spread in the East-European countries. This disease has similar symptoms with the Loose Smut of Barley. The stem components are completely destroyed and replaced by a black mass of spores. These are carried by the wind and stick to the healthy plants or remain on the soil. The difference between these 2 diseases is that the False Loose Smut appears 10 days after the Loose Smut of Barley.
barley hordeum vulgare Ustilago nigra
Prevention and control measures:

  • Planting resilient species;
  • Correct crop rotation;
  • Treating the seeds before sowing represents the main prevention method. Products to be used: Vitavax, Dividend Star , Kinto Duo;

Covered Smut, caused by Ustilago hordei:

The plants grow premature spikes. The spike’s components are destroyed and replaced by a black mass of spores. The spore mass is covered by a silver membrane, which give the spike a compact aspect. During harvesting, the spikes break apart and release the fungus’ spores. These end up on the healthy seeds or remain on the ground. In both cases, they will cause infections in the years to come.
barley hordeum vulgare Ustilago hordei
Prevention and control measures:

  • Planting resilient species;
  • Correct crop rotation;
  • Sowing at the correct time;
  • Ploughing at the necessary depth;
  • Correct density;
  • Treating the seeds before sowing represents the main prevention method. Products to be used: Vitavax, Dividend Star , Kinto Duo;

Dwarf Bunt, caused by Tilletia pancicii:

The attack on barley is similar to the attack the wheat. The infected spikes have a green to blue color and a pale-yellow color when they are mature. The spikes are rigid, the stems are short and fragile. The affected seeds have a compact aspect. Their contents are destroyed and replaced by a black spore mass. The affected plants are smaller than the healthy ones. During harvesting, the seeds break and release the spores. The spores remain on the soil or stick to the healthy seeds.
barley-hordeum-vulgare-Tilletia-pancicii
Prevention and control measures:

  • Deep summer ploughing;
  • Sowing during the correct time;
  • Correct crop rotation;
  • Cleaning the machines before using them of different crops;
  • Treating the seeds before sowing. Products to be used: Amiral Proffy, Divident, Orius 2 WS;

Barley Brown Rust, caused by Puccinia hordei:

On the superior side of the leaves circular, orange colored pustules grow. As the disease evolves, on the inferior side of the leaves, small, black pustules appear, which are chaotically placed in circles. After the attack, the photosynthesis capacity is reduced and the production decreases.
barley-hordeum-vulgare-Puccinia-hordei
Prevention and control measures:

  • Plating resilient species;
  • Sowing during the correct time;
  • Balanced fertilizing;
  • Chemical treatments, using: Zamir, Mirage, Orius, Artea, Amistar Xtra;

Barley Scald, caused by Rhynchosporium secalis:

Small, green to blue spots appear on the leaf and its stem. The spots grow and turn yellow, surrounded by a brown edge. They eventually unite and cover up large surfaces of the lead. After the attack, the leaves dry out and black spots appear on the seeds. This disease is favored by the lack to crop rotation and a high humidity.
barley hordeum vulgare Rhynchosporium secalis
Prevention and control measures:

  • Implementing a crop rotation that does not contain wheat and rye;
  • Treating the seeds before sowing. Products to be used: Divident, Orius 2 WS;
  • Chemical treatments during the vegetation period, using: Bumper, Mirage, Zamir;

Stripe Rust on Barley, caused by Puccinia striiformis:

This fungus attacks all the organs from the plant’s shoot system. Orange, rectangular pustules grow on the infected organs, pustules which are parallel to one another. The infections start from the base leaves and, in severe cases, it can affect the spikes. After the attack, the leaves will prematurely wilt, the spikes will stop growing and the seeds will be empty.
barley hordeum vulgare Puccinia striiformis
Prevention and control measures:

  • Planting resilient species;
  • Sowing during the correct time;
  • Balanced fertilizing;
  • The products used to prevent the barley brown rust can also be used against stripe rust;

Fusarium Head Blight, caused by Gibberella zeae:

This disease affects the crops during hot and dry years. The disease attacks the plant since its first stages of growth, when brown spots appear on the plants’ little stems. After the attack, the stems rot. If the fungus attack in the sprouting stage of the plants, the plants will have a brown area at their bases. They will remain small and under-developed and their spikes will be under-developed and brown. The worst attack affects the plant during its sprouting stage, when the spikes turn white and red. At the base of the white spikes, a pink mold or orange colored bumps grow, which represent the fungus’ fruitions. The seeds are frail and have no germinative properties. During the plant’s vegetation period, the disease is transmitted through the fungus’ spores and mycelium. The disease lives from one year to another through the infected seeds.
barley hordeum vulgare Gibberella zeae
Prevention and control measures:

  • Balanced fertilizing;
  • Avoid a lack of crop rotation or wheat-corn rotation;
  • Planting resilient species;
  • Treating the seeds before sowing. Products to be used: Amiral Proffy, Divident, Orius 2 WS;
  • Chemical treatments to be applied during the spikelet stage. Products to be used: Bumper, Zamir;

Stem rust (Black rust), caused by Puccinia graminis:

The symptoms of this disease are pustule formations which grow on all the organs from the shoot system, especially on the stems. This is why this disease is called the stem/black rust. The difference between the stripe rust and brown rust is represented by the fact that the attack starts on the superior side of the plant.
barley hordeum vulgare Puccinia graminis
Prevention and control measures:

  • Planting resilient species;
  • Sowing during the correct time;
  • Balanced fertilizing;
  • Products which help fight the brown rust and the stripe rust can also be used for the stem/black rust;

Main pests

Scarab Beetle (Anisoplia spp):

This pest grows a generation once every 2 years and spends the winter as a larva. The adults feed on the flowers’ ovaries. After the attack, the seeds are destroyed either partially or completely. The larvae are not dangerous.
barley hordeum vulgare Anisoplia spp
Prevention and control measures:

  • Performing a thorough ploughing after harvesting;
  • Correct crop rotation;
  • Chemical treatments need to be applied when, on a square meter, there are more than 5 adults. Products to be used: Proteus, Pyrinex 25 CS, Biscaya, Fury, Mavrik;

Green Bug/Wheat Aphid (Schizaphis graminum):

It grows 15-20 generations per year and spends the winter as an egg on the barley or on the spontaneous species. The adults and the larvae colonize the leaves and the stems, sucking the sap from the tissues. The affected leaves have red colored spots, they curl and then wilt. The severe autumn attacks lead to plant wilt, the attacks performed during the seeds formation period leads to a production decrease.
barley hordeum vulgare Schizaphis graminum
Prevention and control measures:

  • Sowing during the correct time;
  • Destroying the spontaneous crops;
  • Treating the plants when there are more than 10 adults on a plant. Products to be used: Confidor Energy, Mavrik, Nurelle D, Actara, Biscaya;

Corn Ground Beetle (Zabrus tenebrioides):

It grows one generation per year and it spends the winter as a larva, inside the soil. It comes out right after the snow melts. The adults feed on the flowers and seeds in their different growth stages. The larvae only feed on the plant’s shoot system, never on the roots. They attack the leaves, pull them inside the galleries they have dug and torn them apart. The affected plants are completely destroyed.
barley hordeum vulgare Zabrus tenebrioides
Prevention and control measures:

  • Treatments, using Actara, Biscaya, Karate Zeon, Fury, Kaiso Sorbie;

Cereal Leaf Beetle (Lema melanopa):

It grows one generation per year and it spends the winter as an adult in the foliage of the spontaneous plants from the side of the roads, in forests, etc. the adults normally come out during the second part of April, lay the eggs on the superior side of the leaves, near their base, parallel to the main vein. The adults chew on the leaves, punching holes on both epidermis and parenchyma, the larvae eat the inferior epidermis and parenchyma, leaving intact the inferior epidermis. If the attack is severe, only transparent membranes can be seen from the entire plant; the plants end up having an overall white color. This pest attacks the plant’s growing places, the areas attacked can be seen as white spots in the field.
barley hordeum vulgare Lema melanopa
Prevention and control measures:

  • Chemical treatments need to be applied if there are more than 10 adults or 250 larvae. Products to be used: Actara, Biscaya, Karate Zeon, Fury, Kaiso Sorbie;

Barley Thrips (Limothrips denticornis):

It grows 2 generations per year and it feeds on different spontaneous or planted crops, but it prefers the barley. This insect attacks the spikes, stems and pods. After the attack, the spikes are atrophied either partially or totally. The stem twists and curls on its upper part. If the attack is severe, the spikes no longer grow seeds, or, the seeds they grow are empty.
barley hordeum vulgare Limothrips denticornis
Prevention and control measures:

  • Sowing during the correct time;
  • Correct crop rotation;
  • Autumn ploughing;
  • Treatments to be applied when there are more than 8 adults on a plant. Products to be used: ctara, Biscaya 240 OD, Decis Mega 50 EW, Faster 10 CE, Fury 10 CE, Kaiso Sorbie 5 WG.

European Wheat Stem Sawfly (Cephus pygmaeus):

This is a polyphagous pest (it attacks the barley, too) which grows one generation per year and which spends the winter as a larva on the vegetal residues from the surface of the soil, or inside the soil. The adults come out during May-June and lay the eggs inside the knots underneath the spikes. After they hatch, the larvae chew the inside of the stems. The spikes no longer develop and turn yellow. Rains and winds can lead to spike breakage.
barley-hordeum-vulgare-Cephus-pygmaeus
Prevention and control measures:

  • Deep ploughing;
  • Correct crop rotation;
  • Chemical treatments, using Proteus, Pyrinex 25 CS, Biscaya, Fury, Mavrik;

Barley pest flies:

The barley crops are attacked by more than one species of pest flies. These are hard to identify, even to a specialist eye. During long and dry autumns the attack of these species is severe. The adults lay the eggs inside the stems and in the root-stem areas. After they hatch, the larvae chew the interior of the stems, making the leaves turn yellow and stop developing. The plants have a large number of knots, a small quantity of spikes and seeds.
barley hordeum vulgare Pest Flies
Prevention and control measures:

  • The main prevention method is sowing during the correct time. In this way, the plants will grow after the insect will have fulfilled its biological cycle, making the attack minimum.

Wheat Bug (Aelia spp.):

It grows one generation per year and it spends the winter as an adult inside the forests’ foliage or in other sheltered places. The adults come out during spring and lay their eggs on the plant’s shoot system organs. The adults and the larvae feed on the cellular juice of the leaves, stems, spikes and seeds. when this pest attacks the spike, the area above the sting turns white and no longer grows seeds. The seeds affected during their first development stages become wrinkled.
barley hordeum vulgare Aelia spp.
Prevention and control measures:

  • Chemical treatments, using Proteus, Pyrinex 25 CS, Biscaya, Fury, Mavrik;

Corn Bug (Eurygaster spp):

It grows one generation per year and it spends the winter as an adult inside the forests’ foliage or in other sheltered places. The adults come out during spring, when the temperatures exceed 9 degrees Celsius. The adults lay their eggs on the organs from the plant’s shoot system. Both the adults and the larvae feed on the cellular juice of the leaves, stems, spikes and seeds. When this pest attacks the spike, the area above the sting turns white and no longer grows seeds. The seeds which have been attacked during their first development stages, become wrinkled.
barley hordeum vulgare Eurygaster spp
Prevention and control measures:

  • Chemical treatments, using Proteus, Pyrinex 25 CS, Biscaya, Fury, Mavrik;

                         

 

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