Diseases of winter grain crops during the spring-and-summer period

In a note recommendations about carrying out preventive and protective measures in fight against diseases of grain crops are presented.

Reorganization 2002

         The phytopathologic situation in the territory of the Crimea remains difficult. In many areas because of violation of the agrotechnology, insufficient volume of protective measures and favorable weather conditions accumulation on fields of grain crops of an infectious stock of causative agents of diseases proceeds. Existence of such stock of an infection leads to mass development and distribution of diseases, as it was noted in 2007-2008 in 3-4 weeks prior to cleaning winter grain. In a phase of dairy ripeness in crops grain mass development of a yellow rust, septorioza, mealy dew, gelmintosporioza, a brown sheet spottiness was noted.

         In the conditions of expected early spring of the current year, after rewintering, plants leave weakened, especially outgrown,  there is a probability of distribution of many diseases which activators are mushrooms, bacteria, viruses.

         Differences of the temperature mode, the increased humidity, last year’s stock of an infection, poor-quality protravlivaniye of seeds will promote very early manifestation of root gnily, mealy dew, septorioza, askoxitoza, a brown sheet rust, mycotic diseases.

         Preventive and protective measures fungicidami in fight against these diseases most effectively to carry out to the kushcheniye period (in introduction of herbicides). And application fungicidov at fight against a brown sheet rust, fuzariozy, an olive mold, septoriozy on an ear is expedient in an exit of plants in a tube – naliva grains. High efficiency for improvement of plants is provided by processing of crops fungicidami: Alto-super 330E, k.e., Bayleton, item page, Bumper, page of the item, Impakt, 25S, k.s., Kolfugo super, century of page, etc.

         At not carrying out protective measures the shortage of a grain yield of grains from a complex of diseases in epifitotiyny years can reach 25-50 % and more.

         Rust.

 The rust of grain cereals is caused by mushrooms of a class of Bazidiomitseta, Rzhavchinovye’s order.  The main type of defeat – education uredo pustul on the struck fabrics. They serve for reproduction of a mushroom and mass infection of plants.

Injuriousness. The rust sharply reduces immunity of plants, drought resistance, winter hardiness, a water mode, increasing a transpiratsiya, causing decrease in photosynthetic activity of leaves and breaking metabolism processes in plants that leads to reduction of growth and delay of a phase of a kolosheniye; reduces drought resistance of plants.  Almost annually from this disease it is roughly lost from 15 to 25 % of a crop. Big injuriousness of a rust speaks that the illness has instant and mass character.

          Linear or stem rust. It is shown both on barley, and on wheat. Strikes stalks, sheet vaginas, and sometimes awns and an ear core. On them at first are formed yellow (rusty) oblong summer pustuly-the urediniya, being accompanied by a rupture of epidermis. Then by the end of summer develop black snowing slightly oblong teliopustuly with teleospor.

         Brown sheet rust. The disease is shown on wheat, barley. Strikes leaves, sheet vaginas on which the brown roundish small pillows scattered in a disorder are formed are more rare. Late on growing old leaves, more often from the bottom party, it is possible to find and teleopustuly in the form of the black brilliant small pillows covered with epidermis of a leaf. Yield losses from a brown sheet rust depend on terms of its mass development, firmness of a grade, technology of cultivation. Mass flash of a brown sheet rust on wheat crops in a phase of flowering can cause decrease in productivity twice, and at flash in a phase of dairy ripeness – decrease in a crop to 25-28 %.

         Yellow rust. Strikes wheat, the barley, many types of pasturable and wild-growing cereal herbs. Besides, cereals play an essential role in accumulation and transfer of the infectious beginning, especially the summer and winter periods. A characteristic symptom of an illness is the linear arrangement of urediniya on parts of plants.

          The yellow rust strikes all elevated parts of plants (sheet vaginas, leaves, grains and flower scales.) The mycelium of a yellow rust transfers low temperatures. Distribution and the maximum development of a disease is noted in May – June.

          In farms against a yellow rust the same actions and fungicidy, as against all other types of a rust are applied. However, it is a mistake. Processing fungicidami plants in the field, is a little effective. The reasons of it consist in features of development of an illness: as, having taken root into a leaf fabric, the mycelium is capable to extend almost freely in it, irrespective of any contact fungicida. In this regard, against a yellow rust it is expedient to apply fungicidy system action.

E.Remeslo, senior research associate of the APP UAAN Crimean institute,

S. Kindruk, deputy chief, head of department of forecasts and diagnostics, State inspection of protection of plants of AR Crimea.