Die-Back Disease

Common Name Die-back Disease La France Disease, Mummy. 

An infrequent and difficult to detect disease. Their habitats are other larger particles or organisms. 

Microscopic Characteristics Particles typically ovoid to polyhedral, measuring 25 or 34 nanometers. Elongated particles measure 19-50 nanometers. Virus particles dwell within hyphal cells or 

History, Use and/or Medical Implications Responsible for many plant, animal and human diseases. Typically viruses are associated with larger carrier particles, particularly bacteria. 

Comments Virus is most likely introduced during or directly after spawning. Infected farms experience losses up to 70%. First reported from Europe, measures of control and prevention have been developed and successfully tested by the Dutch. Most notably, virus spreads by attaching itself to mushroom spores which then become airborne. Virus also spreads through the contact of healthy mycelia with diseased mycelia. Afflicted mushrooms are soon exploited by a host of other parasites, making a late and accurate diagnosis of this contaminant difficult. 

---

Citrus aurantifolia (Rutaceae) Die back disease Lime decline disease East Shewa, Africa Saudi Arabia Arocha et al. (2006) Alhudaib et al. (2009)... 

Mycelium runs through the casing and Then disappears. Die Back Disease (Virus). Discard and begin anew with a virus-free strain. See Chap. XIII. 

Flowering (though not all cultivars flower) is an indication that the tubers are large enough to harvest otherwise, scrape soil away from the roots to check. Maincrop potatoes can be left in the ground and used as required until the foliage dies back. Only store disease-free, undamaged tubers (see also p.271). 

Trunk or branches with oozing lesions branch tips die back. Cause Canker. Bleeding canker is spread by the beech scale, which feeds on the bark, causing wounds that permit entry of the fungus. Control the insect and you ll prevent the disease. For more details on dealing with canker, see Trunk or branches with oozing lesions branch tips die back on page 238. 

Shoots blacken, wilt, and die back. Cause Canker. Also known as dieback, this disease is caused by 2 fungal organisms and most often occurs during rainy weather. Prune and destroy infected shoots thin plantings to improve air circulation. Remove and destroy severely infected plants. If canker has been a problem, use preventive sprays of bordeaux mix. 

Stem tips may die back as a result of disease problems, such as fire blight, or from physical damage to the plant. 

Symptoms Dutch elm disease (DED) causes leaves to wilt, yellow, and drop early. Usually, branches show symptoms and die back one at a time. Sometimes the whole tree will wilt and die suddenly. 

Above right) End of the season As the stems of maincrop potatoes die down, it is wise, especially if you see any signs of disease on the foliage, to out the stems back. The tubers can be left in the soil, but all must be lifted before the first frost. 

---