In the publication diseases of grain crops are described: ordinary or gelmintosporiozny root decay, fuzariozny root decay, tserkosporillezny root decay (fragility of stalks), ofiobolezny root decay, their characteristics and symptoms of a disease of plants.
Reorganization 2002
The root decayed.
The root decayed wheat and some barley are among outwardly a little appreciable, but very harmful diseases of grain cereals. Activators root the gnily – the widespread types of mushrooms living on covers and in seeds, in the soil and on the vegetative remains of the died-off plants. They strike many types of plants from the most various families, easily transfer various climatic and soil conditions.
These diseases infectious, caused by semi-parasites (one or a complex), bringing to rotting, destruction of root and radical parts of plants or to defeat of vascular system. As a result of their harmful action of a plant are oppressed, turn yellow and leaves dry up, the kolosheniye delay, a shchuplost of grain and a pustokolosost, and also death of productive stalks are shown a belostebelchatost, a belokolositsa. The infection root the gnily collects in the soil, especially at permanent cultivation of grain cereals, on the vegetative remains, the transmission of infection with seeds in some cases is possible.
Root decay as manifestation unite in various diseases: decay of sprouts, burn of sprouts, root decay, decay of the basis of a stalk, decay of knot of a kushcheniye, break of a stalk, etc. The term root decay covers the diseases which activators get from the soil into root system or the bases of stalks.
In recent years root decay extended widely and cause a significant damage to agricultural industry. The standard of farming is lower, the losses from them are more considerable. Non-compliance with crop rotations, existence of a monoculture of this or that type of a grain cereal, a low agrotechnology lead to deterioration of structure of the soil, to fertility exhaustion, creation of adverse conditions for development of plants. All this promotes accumulation in the soil of pathogenic mushrooms. In some cases root decay become the reason of mass death of crops.
Signs of defeat various gnilyami are similar with each other. The part of plants happens is infected by two, three activators. Symptoms of diseases can change as a result of presence on the struck body of saprofitny microorganisms. Therefore in field conditions to distinguish them happens hardly.
Seeds, the soil and the vegetative remains can be sources of primary infection. Pathogenic mushrooms are capable to remain in the soil within several years. Duration of a survival in the absence of the main owners depends on in what form the mushroom remains. Konidy of types of the sort Helmhosporium, for example, keep viability till 3 years, konidiya and Ophibolus graminis askospor – 2-4 years, oospores of representatives from the sorts Pythiumi Aphanomyces till 5 years and more, hlomidospor of types of Fusarium – over 5 years. Some types of mushrooms inhabitants of the soil can keep viability extremely long, in communication with what crop rotations for fight against them are often a little effective.
Activators root the gnily possess wide specialization, are capable to strike not only grain and wild-growing cereals, but also plants from other families. This property helps pathogens, in the absence of the main owners, to survive for many years.
Depending on activators distinguish ordinary, fuzariozny, tserkosporellezny and ofiobolezny the root decayed.
Ordinary or gelmintosporiozny root decay.
Its activator – the imperfect mushroom relating to Dematiactiaceae family.
The disease causes pobureniye, deformation and a curvature of sprouts which often perish to an exit koleoptile on a soil surface. At emergence of shoots on a vagina of the first leaf, and later on the basis of a stalk brown strips and spots are found. In a trubkovaniye and flowering there is a pobureniye of knot of the kushcheniye, the first elevated and underground interstice, and also the basis of leaves. In warm damp weather the mushroom often settles on ears, gets into a pericarp and endosperm, causes pobureny zones of a germ. Thereof grain remains underdeveloped and puny. Defeat of this kind call a black germ.
Fuzariozny root decay. It is considered to be activators of root decay imperfect mushrooms of the sort Fusarium. Fuzariozny root decay, as well as ordinary, can cause dying off of sprouts before achievement of a soil surface by them. It causes a pobureniye of primary and secondary roots, an underground interstice and the stalk basis. On these bodies of plants at first there are brown or brown strokes or strips which then expand and often merge and band them. Pobureniye of the basis of a stalk is usually found at the beginning of flowering and considerably increases to harvesting. In damp weather in places of defeats there is a pink raid. In vegetation the illness causes an izrezhivaniye of crops and dying off of productive stalks. The part of the struck plants forms an underdeveloped ear with puny grain, and sometimes remains pustokolosy.
Tserkosporillezny root decay (fragility of stalks).
The illness is shown in the form of a spottiness on the bottom party of a stalk. Spots elliptic, bordered with a "chocolate" border and light-brown in the center. In defeat places the fabric collapses, stalks are bent, polegayut or crack. On the struck stalks a weak smoky raid – a mushroom sporonosheniye.
Ofiobolezny root decay. The activator of ofiobolezny root decay – a marsupial a mushroom. Decay on shoots is shown. Plants lag behind in growth, turn yellow, leaves die off them. Sometimes plants perish. On roots and knot of a kushcheniye there are brown roundish spots which quickly increase and blacken. The illness quite often is at the bottom of a weak kustistost of plants. In ears of the struck plants very puny grain is formed or not formed in general.