In this publication diseases of winter grain crops are described: fuzarioz ear (drunk bread), mealy dew, septorioz, askoxitoz, olive mold (kladosporioz), their characteristics and symptoms of a disease of plants.
Reorganization 2002
Fuzarioz of an ear (drunk bread).
Wheat is surprised generally, barley is more rare. The disease is shown on an ear and grain during the period naliva. On the struck bodies there is a pink raid (a konidialny stage of a mushroom). Defeat is often accompanied by ear decolouration. Late on a place of a bright raid black points – fruit bodies of a sumchaty stage are formed. With cheshuek the mycelium of the activator gets into grain. Sometimes it concentrates in its cover, and at early and strong infection gets in endosperm where decomposes proteins, why grain turns out puny, and having got to a germ, lowers vsxozhest grains. The struck grain sometimes gets a pink shade.
Parasitizing on a plant, especially on grain, the mycelium allocates the toxins poisoning the person and animals. Symptoms of poisoning are a little similar to poisoning with alcoholic beverages therefore the illness received the name of drunk bread.
Injuriousness of a disease is caused by that on the struck grain the activator continues the development in storage conditions, infecting healthy grain if humidity is higher than it norm. The mycelium acting on a surface sticks together grain in dense lumps.
The infection remains on the vegetative remains and in the soil, and also in the struck grain. Infection always has local character. Further mass infection of ears or cones of this plant is made by konidiya which are carried by a rain, insects and a wind.
Epifitoty are observed in years with plentiful loss of a precipitation during the period naliva grains and before cleaning when because of bread rains polegayut and stand in fields.
Mealy dew.
The activator – a marsupial a mushroom. Mealy dew destroys all grain and many fodder and wild-growing cereals. Leaves and sheet vaginas on which there is a raid are surprised generally: at strong development of mealy dew stalks, koloskovy scales and an awn can be surprised. The raid gradually turns into dense mitselialny small pillows. In the beginning it white, then sereet, later bureet.
The disease is very harmful, especially at defeat of plants at early stages of development. The activator takes away nutrients and causes premature dying off of leaves. At average defeat of plants by mealy dew the grain yield decreases to 32-36 %, and at strong manifestation of a disease – it is even more. Such yield losses are caused by that is reduced the general and productive kustistost of plants (instead of 4-6 stalks – 1-4); height of plants. The number of cones and grains in an ear besides decrease, the mass of seeds, worsens quality of grain at the expense of decrease in protein and starch. Infection occurs during the whole vegetative period. Early crops fall ill in the autumn, by spring they can partially die off, and crops of optimum terms of sowing are surprised in the spring. To Zagushchennye crops of optimum density are subject to infection several times more strongly, than.
Septoroioz.
Activators – mushrooms from the sort Septjria.
The activator strikes all elevated parts of plants: koloskovy scales, ear core, stalks, knots, leaves, sheet vaginas, ears. On all bodies dark-brown spots with piknidami are formed. On koloskovy cheshuyax in education places piknid spots brighten. At strong manifestation of a disease ear cores, stalks and knots become dark-brown, almost black, the struck fabric becomes covered piknidami.
On leaves and sheet vaginas originally there are small, dark-brown spots, then the fabric near them turns yellow, spots increase, dry, become covered piknidami, and leaves die off. At defeat on seeds there are not clearly outlined brown spots. Sick plants usually lag behind in growth, strongly cluster, the ear is shortened, in it the number of grains is reduced. In separate years septorioz causes a significant damage to wheat crop.
Infection sources – the infected vegetative remains and seeds. With seeds the activator gets on other fields of a crop rotation, to new areas and zones.
Sick seeds give the infected shoots. In the presence of a precipitation, fogs and dews piknospor with drops of water get on stalks, on again being formed leaves, an ear and grain. Infection occurs through the drops which have settled on plants of water at temperature in limits 5-30oS (an optimum 20-25os). Late terms of sowing, introduction of only nitric fertilizers, a precipitation, especially in a kolosheniye – flowerings promote it. Septorioz leads to reduction of an assimilyatsionny surface and premature drying of the leaves, all plant, decrease in a grain yield and deterioration of its sowing qualities. Yield losses can reach 40 %.
Askokhitoz.
Askokhitoz strikes barley, wheat and is caused by a mushroom.
On leaves of wheat of a spot originally small, roundish or the wrong form, with a dark brown border. In a consequence of a spot merge, cover quite often all plate of a leaf. Leaves become dirty-gray color and dry up. In the center of spots black points – piknidy a mushroom are visible.
Injuriousness askoxitoza consists in a premature usykhaniye of leaves. In the years favorable for development of an illness, a pathogen can cause death of the winter.
Olive mold (kladosporioz). Strikes wheat and other grain cereals, especially weakened plants, in their ripening. The activator – an imperfect mushroom. The disease is shown on stalks, ears, the grains, growing old leaves in a look olivkovo – a velvety raid (a mushroom sporonosheniye).
E.Remeslo, senior research associate of the APP UAAN Crimean institute,
S. Kindruk, deputy chief, head of department of forecasts and diagnostics of the State inspection of protection of plants.