Conditions of autumn and winter of 2006-2007 promoted considerable development of wreckers and diseases on crops of winter grain crops.
Authors of article characterize a number of diseases and wreckers, make recommendations about preventive, treating and eradicating methods of fight.
Conditions of the autumn and winter period of 2006-2007 promoted considerable development of harmful organisms on crops of winter grain crops. The last year’s stock of an infection under favorable weather conditions can cause in the spring early manifestation of the whole complex of diseases. Violation of technology of cultivation (a choice of the predecessor, sowing terms, quality of disinfecting of a sowing material can be the reason of distribution of diseases as, etc.) Development on winter grain listostebelny diseases will depend in many respects on developing weather conditions. If the spring is warm and damp, on winter wheat of early and optimum terms of sowing mealy dew, a brown sheet rust, septorioz will develop; on winter barley, except for late crops – mealy dew, gelmintosporiozny a spottiness. In the autumn in some regions of the Crimea defeat of crops root gnilyami was revealed.
The main role of a photosynthesizing surface of a plant is directed on creation of the filled and healthy ear with high mass of 1000 grains and high quality.
It is necessary to represent well, to what losses conducts an exception or the wrong application fungicidov. For example, default of the actions directed on creation of a healthy flag leaf, can lead to a yield loss to 50 %. The disease of a young plant, for example, mealy dew is especially dangerous. Fight against mealy dew, irrespective of other actions, always conducts to increase of weight of 1000 grains.
Mealy rosaporazhaet at first the bottom leaves, then passes to the top. 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 are surprised in the spring. To Zagushchennye crops are subject to infection several times more strongly, than crops of optimum density. Injuriousness of an illness comes to light in reduction of an assimilyatsionny surface, chlorophyll destruction. Intensive development of an illness can cause reduction of quantity and weight of grains and a crop shortage to 15 %, and in days of epifitotiya – 30 % and are more.
Brown rzhavchinapshenitsa it is shown mainly on leaves, is more rare – on sheet vaginas and stalks. Infection of plants occurs at temperature from 2,5 to 31°S (an optimum 15-25°C) in the presence of dew or rain drops on leaves. Injuriousness of a brown rust depends on time of its emergence in a large number – than earlier it appears, it is more dangerous than subjects. The greatest danger is represented by mass autumn emergence of a brown rust on crops of winter wheat, especially when weather conditions of the next spring and the beginning of summer favor to further development of an illness. Autumn emergence of a rust on crops winter leads to sharp fall of winter hardiness of plants of wheat. Mass flash of a brown 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 harvesting reaches 25-28 %.
Septorioz appears on leaves, sheet vaginas, stalks, an ear of winter wheat. Infection occurs in the presence of water drops on plants and temperature in limits 5-30°S (an optimum 20-25°C). Defeat of crops is promoted by late terms of sowing, introduction of only nitric fertilizers, long damp and warm wind weather, a precipitation, especially in a kolosheniye – flowerings. Septorioz leads to reduction of an assimilyatsionny surface, premature drying of leaves and plants, decrease in a grain yield and deterioration of its sowing campaigns and technological qualities. Yield losses can reach 40 %.
Mesh gelmintosporioz barley strikes crops of early terms more. Yield losses at intensity of defeat from 50 to 70 % reach 33-50 %.
In vegetation of the winter grain it is necessary to apply to protection of crops against diseases fungicidy taking into account a range of their action, economic and ecological justification. Expediency of their application is determined by results of inspections of a fytosanitory condition of crops and an expected yield loss at this level of development of diseases on each field.
Actions for fight against fungoid diseases can be: preventive, treating and eradicating.
The most effective are preventive actions. But in any case fungicidy should be applied prior to the beginning of epidemic instead of when it began. At already progressing disease and the best fungicidy can’t cope with it.
Against a complex of diseases it is necessary to apply to protection of crops fungicidy a wide range of action: alto-super-0,4 – 0,5 l/hectares, impakt – 0,5 l/hectares, the absolute – 1,5 l/hectares, amistar extra, derozal. – 0,5 l/hectares, etc. It is necessary to determine expediency of their application by results of fytosanitory inspection of a condition of crops which experts in protection of plants should see off only.
Along with diseases, crops of winter crops are harmed by insects – fitofagi.
From the moment of shoots and in the subsequent crops of winter grains can be damaged by cereal plant louses among whom dominates Big Cereal and Ordinary more often. Injuriousness of a plant louse consists in weakening of plants and in transfer of an infection of a virus of a yellow karlikovost of barley (VZhKYa). It is not necessary to reduce risk from distribution of a plant louse because threat of infection of crops of VZhKYa in the spring remains. The virus is very harmful and extends on all bodies, the shortage of a crop can make 20-30 %. Against cereal plant louses and flies it is possible to apply bi-58 the new – 1,5 l/hectares, bazudin, 60 % of century e. – 1,5 l/hectares, decis forte – 0,05 l/hectares, zolon – 1,5 l/hectares, danady – 1,0-1,5 l/hectares, rogor-S – 1,5 l/hectares, kinmiks – 0,2 l/hectares, sherpa – 0,2 l/hectares, fastak – 0,2 l/hectares, fyuri – 0,07 l/hectares.
The grain ground beetle harms considerably to winter crops in the autumn and continues the food in the spring. At existence to a phase of a kushcheniye of 2-3 larvae on 1 sq.m carry out spraying of crops bazudiny, volatony, nurely D, etc.
In an exit phase in a tube, in order to avoid grain yield losses from a bug-cherepashki (not less than 2 individuals on 1 sq.m, crops process one of preparations: volaton 500, BI-58 new, decis, karate, sherpa, sumition, etc. Fight against bugs of the grain ground beetle, as a rule, unite with chemical protection of crops against bug larvae a harmful cherepashka.
For a start it is necessary to survey crops, especially on sternevy predecessors, and in the presence of 2-3 larvae on sq.m to carry out spraying. Against the grain ground beetle it is possible to apply insecticides: Damascus-1,5-1,8 l/hectare, fostran-1,5½/hectare, nurel D-0,75-1,0 l/hectares, etc.
In a phase a kushcheniye-exit in a tube it is necessary to pay attention to existence on crops of the wintered bugs a harmful cherepashka. Adult bugs which perfectly wintered, occupy crops, eat exclusively vegetative bodies of plants. Damages of plants at early stages of development (a spring kushcheniye) can lead to death of a plant. In the presence of the 2nd bugs on sq.m carry out processing by insecticides.
In an exit phase in a tube there can be a threat from tripsov and a cereal listovertka. At number tripsov – the 10th imago/ear and 0,5 larvae/plant or 10-15 % of damage of a sheet plate a cereal listovertka, a pyavitsa it is possible to carry out spraying by insecticides.
The huge competition between young plants grain and weeds – bad start for crop formation. Weeds are much stronger than cultural plants, they ascend quicker and extend on the big areas, actively absorb moisture, nutrients, light, air, suppressing development and a laying of bodies grain, causing productivity. Unlike other factors, temporary, harm done by them – constant and systematic. On the littered fields it is impossible to receive complete return from the fertilizers, new highly productive grades and the agroreceptions directed on increase of a crop. Even at such strong and competitive culture as winter wheat of a yield loss from weed vegetation can reach 50 %. For control over weeds and decrease in their quantity there are many ways. It both observance of crop rotations, and system of processing of the soil, agrotechnical and chemical receptions.
High level of a contamination of crops by weeds doesn’t give possibility in the next years to refuse from uses of herbicides. It is necessary to give special attention to fight against the long-term and malicious weeds which distribution in recent years strongly increased: sow-thistle pink, sow-thistle yellow, ambrosia polynolistny, wheat grass creeping, etc. At the correct application of herbicides these weeds are rather easy for destroying just in crops of winter wheat. These and other weeds lead to decrease in productivity of winter wheat and are threat for the subsequent cultures. After winter wheat, as a rule, in a crop rotation sow propashny cultures, to fight against weeds in them much more difficult and additional expenses are required.
Special problem this year is the contamination of crops of winter grain crops. Inspections of crops showed that the contamination of winter grain crops is higher than average (more than 25-50 pieces of weeds on sq.m) therefore processing of crops by herbicides can be begun in the early spring at existence of 3-36 copies on sq.m depending on dominating types.
The researches which have been carried out on Crimean GSXOS, confirm that it is enough one processing by herbicides for effective destruction of bulk of weeds in crops of winter wheat.
For this purpose it is necessary to pick up correctly: herbicide, depending on the main most problem types of weeds which more than others will oppress cultural plants; term of introduction and norm of an expense of a preparation. At violation of these rules even the most advanced preparations can not give expected result and to make negative impact on development of cultures.
On winter grain spraying by herbicides is necessary for carrying out, since the most developed crops and to carry out to an exit winter to a tube. In the conditions of cool spring at the lowered temperature mode application of preparations on the basis of 2,4 D will be inefficient, it is desirable therefore to process herbicides which "work", since +5°S (lintur, 70 WG-0,15 of kg/hectare, grodil ultra – 0,1-0,15 kg/hectares, granstar of-15 g/hectares etc.).
These preparations if necessary can be applied and in a phase of an exit of plants in a tube.
If temperature 18 ° and above, on the developed crops it is possible to bring any preparation, including and 2,4.
It is necessary to remember that herbicides on the basis of 2,4 D only temporarily oppress a sow-thistle, and preparations such as dialen super, granstar, etc. well it suppress.
It is not recommended to carry out processing of cultural plants which are in a stressful condition, preparations on the basis of metsulfuron-methyl (gerbilan, item page, laren, 60 % of page of the item, a magnum, EL of, the battle ship, century of, saracin, item page, a range, item page etc.). When processing the cultural plants being in the weakened and stressful condition, it is recommended to apply lateral mixes of herbicides with growth regulators (Mars – EL, Agate – 25 To, the Pendant). For increase of efficiency of processing of crops from weeds we recommend to use the combined herbicides or mixes of herbicides on the basis of two – three active ingredients (lateral mixes).
Effectively to use the combined herbicides: dialen With (dimetilaminny salt + dikamba), the cowboy (xlorsulfuron + dikamba), lintur (triasulfuron + dikamba), mikodin (2,4 D + dikamba) which affect destruction annual two-submultiple, including resistant to 2,4.
Lateral mixes of herbicides are effective: Granstar + saracin, gersotil + saracin or a range in polovinny doses; granstar or gersotil + 2,4 D an asset or esteron at deficiency of moisture; saracin or a range + an optimum or dikamba Plus in the presence of korneotpryskovy weeds.
Recently the question is actual: whether application of lateral mixes is possible: herbicide + insecticide, herbicide + fungicid. In many cases there is a need of simultaneous protection of plants from harmful organisms different in the nature. For this purpose apply lateral mixes of pesticides. For application of mixes it is necessary to adhere to certain requirements: the clash of dates of application of components, physical and toxic compatibility to avoid negative influence on cultural plants (deformation of leaves, stalks, an ear, burns, etc.).
It is necessary to remember that the problem of selection of components for lateral mixes is insufficiently well studied therefore to approach to this reception it is necessary carefully. Are well compatible the majority fungicidov to insecticides, and mixes of insecticides and fungicidov with herbicides aren’t desirable (except special exceptions, for example, wheat spraying in the spring group 2,4D herbicides) because it can lead to damage or death of cultural plants. At application of such mixes we recommend to address for scientific advisers, in scientific institutions and in the firms which are engaged in realization of means of protection of plants.
In the conditions of 2007 there were conditions optimum in recent years for development of weeds and diseases therefore for the maximum preservation of a crop of winter grain crops it is necessary to carry out as soon as possible processing by herbicides and surely one, and if necessary two processings by preparations of fungitsidny action.
S. Pelagenko, the first deputy minister of an agrarian policy of AR Crimea, L.Radchenko, the deputy director on scientific work, O. Romashova managing laboratory of agriculture, the candidate of agricultural sciences, N. Saenko, the senior research associate of laboratory of agriculture, the candidate of agricultural sciences, S. Tomashov, the research associate of laboratory of agriculture, E.Remeslo, the senior research associate of laboratory of plant growing and a kormoproizvodstvo.