Septoria avenae blotch
Septoria avenae blotch is the most common oat disease in Western Australia. It occurs throughout the cereal growing areas and is most severe in the high rainfall areas.
The disease is caused by the fungus Parastagonospora avenaria f.sp. avenaria (synonym: Phaeosphaeria or Stagonospora avenae f.sp. avenaria). It is not one of the septoria diseases of wheat, which are caused by different species.
The fungus infects leaves (Figure 1), sheaths and stems (Figure 2) and may also infect heads. Symptoms begin as mottled light and dark brown blotches, with dark brown centres. They are restricted and distinct at first but may enlarge to cover most of the leaf.
Figure 1 Leaves affected by septoria avenae blotch
See Also
Oat Allergy: What You Need to KnowIs It Okay to Eat Oatmeal at Night? Foods for a Restful SleepNutritionists: The Prep Shortcut That Makes Oats 4 Times Healthier & Tastes Great Too!Oats Crop UPSC Notes - About, History, Climate Requirements, Soil Conditions, Farming Techniques, Physiology, Crop Development, Diseases, Harvesting, Oat Economy, Top Ten Oat Producing Countries, Top Oat Producing States, Major Oat Producing States Map, I
Figure 2 Stems affected by septoria avenae blotch
Lesions in the leaf sheath extend into the stem causing death and blackening (Figure 2) which may lead to lodging. The fungus sometimes causes a dark discolouration of the grain (Figure 3) when unseasonably late rain occurs.
Figure 3 Grain showing discolouration from septoria avenae blotch
Septoria avenae blotch may cause up to 50% yield loss and crop lodging in extreme cases but losses of around 10% are more common in high rainfall areas. Tall or slow maturing oats are less likely to be affected by the disease than short (dwarf) or fast maturing varieties (Figure 4).
Figure 4 Tall, late maturing oat varieties (right) are less prone to septoria avenae blotch than short, early maturing varieties (left)
Infected stubble is the main source of carryover infection from one season to another. The sexual stage of the fungus occurs on infested stubble and produces ascospores which are spread moderate distances by wind. Oat stubbles in paddocks rotating from oat probably contribute most of the inoculum to nearby paddocks. In multiple cropped oats where stubble is not destroyed, ascospores land on the new crop in much larger quantities, resulting in the development of earlier and more severe outbreaks.
During the season, the fungus on diseased plants produces splash-borne pycnidio-spores which spread the disease onto new foliage during rain. These spores do not move between paddocks but may also be produced by infested stubble residues and contribute to the development of new disease in multiple cropped oats.
Control
Use more resistant varieties in disease-prone areas if suitable agronomic types are available. For current disease resistance tables see: Oats: choosing a variety.
Sow at the time appropriate for the maturity of the variety.
Foliar fungicide registrations exist for control of this disease, refer to Registered foliar fungicides for cereals in WA.
Septoria avenae blotch can be minimised by not growing continuous oat crops. In continuous oat cropping, stubble from diseased plants should be destroyed by burning or ploughing. Burning is not advised on light soils subject to wind or water erosion. Heavy soils, that is, soils which are 50-60% covered with clods of 2-3cm diameter, may be considered for burning. Following crops should be sown at low speeds into moist soil.
FAQs
Major leaf diseases of oats are stem rust, leaf rust, barley yellow dwarf virus and septoria avenae blotch; their severity changes with seasons.
What is the leaf disease in oats? ›
Crown rust, also known as leaf rust, is caused by a fungus, Puccinia coronata f. sp. avenae. The crown rust fungus is specific to cultivated oat, wild oat and a few other wild grasses, but will not infect wheat, barley or rye.
What disease is in winter oats? ›
Crown rust and mildew are the target foliar diseases in oats. Other diseases are either infrequent or not hugely damaging.
How many days does it take for oats to reach maturity? ›
The growth time for oats can be anywhere from 80 to 110 days, depending on the growing conditions and crop variety. Factors like an abundance or scarcity of nutrients and moisture can lengthen or reduce the time it takes for the plant to reach any given growth stage.
Where are oats mainly grown? ›
Oats are grown in many parts of the world, mainly in Northwest and Eastern Europe, North America, Canada, Australia and China. It is a crop typical of and well adapted to the cooler climates (Nordic countries, Canada).
How to get rid of leaf disease? ›
Provide frequent treatment of neem oil or another fungicide to the foliage. Copper-based fungicides are safe and effective for most plants, but always do your research – copper can be harmful to certain plants. Avoid getting water onto the leaves as it recovers. Keep the plant away from other plants temporarily.
What are the symptoms of leaf disease? ›
Symptoms associated with necrosis include leaf spots, blight, scab, rots, damping-off, anthracnose, dieback, and canker. Symptoms associated with hyperplasia include clubroot, galls, warts, and leaf curls.
What are the bacterial diseases of oats? ›
| Bacterial diseases |
|---|
| Bacterial blight (halo blight) | Pseudomonas coronafaciens pv. coronafaciens |
| Bacterial stripe blight | Pseudomonas coronafaciens pv. striafaciens |
| Black chaff and bacterial streak (stripe) | Xanthom*onas campestris pv. translucens |
Major leaf diseases of oats are stem rust, leaf rust, barley yellow dwarf virus and septoria avenae blotch; their severity changes with seasons.
What is the GREY speck disease of oats? ›
Grey speck disease of oat and barley is a non pathogenic deficiency disease. It occurs due to deficiency of manganese. In the case of severe deficiency, the crop can die completely.
Young oats are thirsty; keep them happy with consistent moisture. As they mature, let the soil start to dry out before you water again. In spring or fall, you might get away with less frequent watering—unless you're living in a rain shadow, then it's all hands on deck.
What is the best crop to grow after oats? ›
More desirable rotational crops include: canola, hayfields, peas, lentils, soybeans, and/or other legumes. Pulses give the oat crop a strong yield potential by providing nutrients and reducing disease risk.
How late can you plant winter oats? ›
Spring oat or winter oat can be planted for for- age in late February to late March in a tilled seed- bed or in a suppressed grass sod.
Which country is famous for oats? ›
About a quarter of the more than 22 million tons of the global production -by far- is harvested in Russia, followed by Canada, Poland, Australia and Finland.
Where did oats originally come from? ›
A member of the grass family, oats are believed to have originated from western Asia and eastern Europe. Evidence suggests Paleolithic hunter-gatherers ate wild oats approximately 32,000 years ago in what's now southern Italy, and Neolithic people cultivated them some 11,000 years ago in the West Bank's Jordan Valley.
Can you eat raw oats? ›
Yes, oats can be eaten without cooking. For example, there are a number of no-bake cookies containing oats that are very popular. However, because some individuals have more sensitive digestive tracts, it is a good idea to introduce raw oats to your diet slowly and to drink some fluids when eating the oats.
Are weevils in oats safe to eat? ›
Usually people first notice an infestation when they see moths flying around the pantry or black weevils in stored food. Some weevil species even fly. This calls for immediate and thorough action – but they won't harm you. “It doesn't hurt if you eat them and it's all extra protein,” Blackburn says.
Why are oats sprayed with glyphosate? ›
Oats aren't genetically modified, but many farmers still spray the weed killer on oats to dry the plants out at harvest time. Called desiccation, this practice allows farmers to skip the step of cutting oats and letting them dry in the field.
What causes leaf spot disease? ›
Most leaf spot diseases are caused by fungi, although other organisms, such as bacteria and nematodes, can also cause foliar diseases.
