Oat treatments, most common diseases and pests of this cereal

oat avena sativa

oat avena sativa
The oat (Avena sativa) is a highly known and cultivated plant, worldwide. Even though most of the production is used in the animals’ diets, the oat is an important nutrient source for people, too. The oat seeds contain calcium, iron, manganese and zinc. These have a cleansing, tonic, calming and laxative role. The oat seeds contain a considerable quantity of fibers. These stimulate the digestion and help the digestive system in its function.

Main diseases

Virosis:

Barley yellow dwarf virus:

The affected plants are darker, they turn yellow or even red after some time. This virosis affects the plants since its first stages of development. This virus caused a severe plant dwarfism, followed by the lack of spikes. If the plants are attacked during their twinning stage, they grow less and the tips and leaf veins are yellow. The affected plants grow spikes, but a lot of spikes are sterile. This virus is transmitted through aphids.
oat avena sativa Barley yellow dwarf virus
Prevention and control measures:

  • Destroying the spontaneous plants from the crop;
  • Performing the needed soil maintenance;
  • Sowing during the correct time;
  • Applying pesticides in order to prevent aphids;
  • Planting resilient species;

Mycosis:

Semiloose smut of oats (Ustilago avenae):

Before the spikelets grow, the plants are easily recognized as their tips are yellow. The affected plants’ inflorescence appears later and the spikelets are transformed into a black spore mass. The symptoms of this disease are influenced by the weather conditions. On a moist and chilly weather, the development rhythm of this of this disease is slowed down, the spore mass is consolidated and the spikelets are partially destroyed. On a dry and warm weather, this disease rapidly evolves, the spores are released faster.
oat avena sativa Ustilago avenae
Prevention and control measures:

  • Planting resilient species;
  • Treating the seeds is the most effective prevention method. Products to be used: Vitavax, Dividend Star , Kinto Duo;

Covered Smut, caused by Ustilago levis:

This is as common as the semiloose smut. The symptoms are similar, but the Covered Smut does not attack all the spikelet’s organs, only some of them. The seeds are transformed into a black spore mass. The spore mass is eventually released. The releases spores wither stick to the healthy seeds or fall on the ground.
oat avena sativa Ustilago levis
Prevention and control measures:

  • Treating the seeds before sowing with products used in the treatment of the semiloose smut;
  • Early sowing;
  • Balanced fertilizing to increase the plants’ resistance;

Barley Crown Rust, caused by Puccinia coronata:

The first symptoms can be seen during June-July. On the superior side of the leaves circular pustules grow, irregularly displayed. These are orange at first and covered by the epidermis. After the epidermis breaks, the spores are released and the pustules become dusty. During the last days of summer, black pustules appear, which are placed around the orange pustules.
oat avena sativa Puccinia coronata
Prevention and control measures:

  • Planting resilient species;
  • Destroying the spontaneous plants from the crop;
  • Summer ploughing performed after harvesting to dig the fungus’ spores into the soil;
  • Balanced fertilizing;
  • Chemical treatments, using Zamir, Mirage, Orius, Artea, Amistar Xtra;

Leaf Stripe, caused by Pyrenophora avenae:

The symptoms of this disease are visible on the superior side of the leaves, where small, yellow spots appear. As the disease evolves, the spots grow bigger. On the surface on the spots brown stripes can be seen. These grow and the spots become covered by a silky fluff. After the attack, the leaves become yellow and wilt. If the weather conditions are favorable, the disease attack the spikes. These spikes grow frail seeds, of a yellow-brown color, which will carry the disease to the next year. The disease can also live on the vegetal residues from the surface on the soil and caused infections in the next years.
oat avena sativa Pyrenophora avenae
Prevention and control measures:

  • Respecting an optimum density;
  • Destroying the spontaneous plants from the crop;
  • Correct crop rotation;
  • Balanced fertilizing;
  • Using certified seeds which come from reliable sources;
  • Chemical treatments, using: Nativo, Mystic, Amistar Xtra, Menara;

Powdery Mildew on Cereals, caused by Erysiphe graminis:

This disease starts attacking the crops in spring. On the plant’s base leaves, felt looking like, white spots appear. The spots turn dusty, and circular formations appear on the spots, which represent the fungus’ fruition. The attack can rapidly spread and it can attack even the inflorescences. The affected tissues become yellow and wilted. The leaves prematurely wilt, the spikelets no longer grows as it should, the plant produces frail seeds. The fungus spends the winter on the vegetal residues from the surface of the soil. Moist, autumn weather can cause autumn infections. This disease is favored by excessive nitrogen fertilizing, a lack of crop rotation or sowing high densities.
oat avena sativa Erysiphe graminis
Prevention and control measures:

  • Burying the vegetal residues by ploughing;
  • Destroying the spontaneous plants from the crop;
  • Balanced fertilizing;
  • Planting resilient species;
  • Applying 1-2 treatments during the phenophase, using Bumper, Topas, Kumulus, Mirage, Zamir;

Stem Rust, caused by Puccinia graminis:

The symptoms of this disease are visible in the form of pustules which grow on all the organs from the plant’s shoot system, especially on the stem; this is why this disease is called the stem rust. Compared to all other rust disease, where the attack starts from the base of the plants, in the case of the stem rust, the attack starts on the superior organs of the plant and spreads to the rest of the organs.
oat avena sativa Puccinia graminis
Prevention and control measures:

  • Avoid excessive nitrogen fertilizing;
  • Planting resilient species;
  • Balanced fertilizing;
  • Chemical treatments, using Zamir, Mirage, Orius, Artea, Amistar Xtra;

Head blight of maize, caused by Gibberella zeae:         

This disease attacks during warm and dry summer days. The disease is visible since the plant’s first development stages, when, on the little stems, brown spots appear. After the attack, the stems rot. If the fungus attacks in the knot growing stage, the plants will have brown spots at the base of the stems, too. These remain small, grow under-developed, brown spikes. The attack affects the plant the most during the spikelet forming stage, when the spikelets turn white and red. At the base of the whitened spikelets a pink mold grows, or orange bumps, which represent the fungus’ fruition. The seeds are frail and lose their germinative properties. This fungus is transmitted during the vegetation period by the fungus’ spores and mycelium. The disease lives from one year to another in the form of infected seeds.
oat avena sativa Gibberella zeae
Prevention and control measures:

  • Balanced fertilizing;
  • Lack of crop rotation or just a wheat-corn crop 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 plant’s first growth stages. Products to be sued: Bumper, Zamir;

Main pests

Oats Thrips (Stenothrips graminum):

It grows a generation once every 2 years and it spends the winter as an adult, inside the soil, at a 30-50 cm depth. This pest also attacks a number of spontaneous plants, not only planted crops. After the attack, the plants have bleached spots on their leaves and spikelets. Also, the spikelets are sterile, their seeds are deformed or empty.
oat avena sativa Stenothrips graminum
Prevention and control measures:

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

Wheat Aphid (Schizaphis graminum):

It grows 15-20 generations per year and it spends the winter as an egg on the oat or or the spontaneous plants. The adults and the larvae colonize the leaves and stems, sucking the sap from the tissues. The affected leaves have red colored spots, become curled and then wilt. The severe autumn attack lead to plant wilt and, during the seeds growing stage, it leads to a decrease in the production.
oat avena sativa Schizaphis graminum
Prevention and control measures:

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

European Wheat Stem Sawfly (Cephus pygmaeus):

This is a polyphagous pest (it attacks the barley too), which grows more than 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 their eggs on the knot located under the spike. After they hatch, the larvae chew the contents of the stems. The spikes no longer develop and turn yellow. Rain and winds lead to stems breakings and spikes falling off.
oat avena sativa Cephus pygmaeus
Prevention and control measures:

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

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 road, forests, etc. the adults normally come out in the second half of April, they lay the eggs on the superior side of the leaves, near the base, parallel with the main vein. The adults chew the leaves, punching holes on both of the epidermises and parenchymas, the larvae eat the inferior parenchyma, leaving the inferior epidermis. If the attack is severe, the entire foliage is destroyed, transparent membranes are left, making the plants look white. The attack takes place in the growing spots from the parcel, which are easily recognizable as white spots in the field.
oat avena sativa Lema melanopa
Prevention and control measures:

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

Ground Beetle (Zabrus tenebrioides):

It grows one generation per year and it spends the winter as a larva, inside the soil. This pest come alive right after the snow melts. The adults feed on the flowers and seeds on their different development stages. The larvae feed only on the plant’s shoot system organs, never on their roots. They attack the leaves, drag them into the galleries they have dug and rip them apart. The affected plants are totally destroyed, the attack is visible in the growing spots on the parcels.
oat avena sativa Zabrus tenebrioides
Prevention and control measures:

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

Scarab Beetle (Anisoplia spp):

It grows one generation once every 2 years and it spends the winter as a larva. The adults feed on the flowers’ ovaries and on the young seeds. After the attack, the seeds are destroyed either totally or partially. The larvae are not harmful.
oat avena sativa Anisoplia spp
Prevention and control measures:

  • Correct crop rotation;
  • Chemical treatments to be applied when there are more than 5 adults on a square meter. Products to be used: 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 on the forest’s foliage or on other sheltered spots. The adults come out during spring, when the temperatures exceed 9 degrees Celsius. After they hatch, they lay their eggs on the shoot system organs. Both the adults and the larvae feed on the cellular juice of the leaves, stems, spikes and seeds. When this disease attacks the spike, the area above the sting becomes white and no longer grows seeds. Young seeds which have been affected become wrinkled.
oat avena sativa Eurygaster spp
Prevention and control measures:

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

Wheat Bug (Aelia spp.):

It grows one generation per year and it spends the winter as an adult on the forest’s foliage or on others sheltered places. The adults come out during spring and lay their eggs on the organs from the plant’s shoot system. The adults and the larvae feed on the cellular juice of the leaves, stems, spike and seeds. When the attack affects the spike, the area above the sting turns white and no longer grows seeds. if they young seeds are attacked, they become wrinkled.
oat avena sativa Aelia spp
Prevention and control measures:

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

Saddle Gall Midge (Haplodiplosis marginata):

It grows one generation per year and it spends the winter as a larva, inside the soil. During the last days of April, the beginning of May, the larvae climb up to the surface of the soil and turn into pupas. The adults come out after 4-5 days and lay their eggs on the superior leaves. The eggs and the larvae are sensitive to dryness. After they hatch, the larvae get into the leaves’ petiole, where they remain. The affected plants have elongated bumps with deepened central areas on their petioles because of the larvae which climbed and remained there. On the affected areas, the stems have all the veins destroyed. This leads to a stop in the plant’s growing and spike forming, premature ripe, reduced number of seeds in a spike.
oat avena sativa Haplodiplosis marginata
Prevention and control measures:

  • Chemical treatments to be applied if there are more than 5-6 larvae on a plant. Products to be used: Confidor Energy, Pyrinex Quick, Actara, Nurelle D, Actellic;

 

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