In the present article concrete recommendations about control of a condition of winter grain crops during the winter and spring period, and also by definition of a condition of crops in rewintering and methods of selection of monoliths on an otrashchivaniye of plants are made by various methods: method of monoliths, water, sugar, method of dyes and biological control.
Methodical recommendations of the Ukrainian academy of agrarian sciences
From history: the lowest minimum temperature in the Crimea was observed in January, 1940 – 31,7°S, in January of 1942 g and in February, 1954 to – 31°S, in 1947 and 1950 the absolute minimum of air temperature went down to-28°S. The Prodolyozhitelnost of the periods of abnormal and cold weather was from 3 to 6 days.
The winter of 2006 showed an urgency of a question of preservation of viability and rewintering of winter grain and forage crops. Conditions at which air temperature fell in the separate regions of the Crimea to 25-29 degrees below zero, on fields with small snow cover can lead to partial or full death winter, and also wintering forage crops.
According to Klepinino’s agrometeorological station, since January 20th of the current year sharp fall of temperature was observed. The absolute minimum of air temperature is noted on January 24th – 29,1°S. Within 5 days (on January 21-25) the minimum air temperature was lower – 20°S. Daily average air temperature fluctuated from-15 ° to – 24°S and was lower than norm on 13-22°C.
The minimum temperature of the soil on depth of knot of a kushcheniye winter in the current year went down at the beginning of a cold snap (on January 21-22 to – 6°S), at height of snow cover of 3 cm, and at the end of the cold period to – 5,5°S, at height of a cover of snow 11 see Promerzaniye the soil reached 18 see. The average height of snow in the field, by data snegosemok, on fields of the APP Crimean institute made on January 20th – 2 cm, on January 25th – 11 see. Wind strengthening to 12 m/s was adverse. and drifting snows that promoted snow redistribution on fields. About 20 % of the areas appeared with small height of snow (2-5 cm). Similar weather conditions were observed in all territory of the Crimea occupied with a winter wedge.
According to a long-term forecast in February the cold wave with very low temperatures practically can repeatedly come, thus their impact on rewintering winter will be considerable as the plants which have transferred the first blow of low temperatures, become less steady.
Rewintering of winter crops depends on a set of factors and, first of all, from observance of timely and high-quality performance of agrotechnical receptions. The majority of grades of the winter crops cultivated in the Crimea, have a necessary stock of frost resistance. So, for grades winter wheat the temperature on depth of knot of a kushcheniye 17-180C below zero ¸ for winter barley – - 14-150C is critical. The settlement critical temperature of a vymerzaniye winter in the third decade of January made: for winter barley – 10,20S, for winter wheat – 140S.
Considering weak training of winter grain crops (warm autumn), absence or insignificant height of snow cover on the regions of the Crimea, influence of low temperatures on plants of winter crops can be pernicious.
At the same time stability of plants to adverse weather conditions varies depending on a phase of development of plants and their condition. Influence of adverse conditions of the winter and early-spring period on plants of winter crops can lead to considerable decrease in their efficiency, and in some cases, and to full death of crops.
Frost resistance of winter plants, first of all, is connected with a water condition in cages and mezhkletnik. Water – the main component of live substance, also is necessary for all biochemical and biophysical processes occurring in vegetative organisms. Cold-resistant plants form ice crystals in mezhkletnik at temperature – 5…-10°C. Endocellular ice at such temperature isn’t formed, as water diffundiruet from a cage in mezhkletnik where crystallizes. However water can leave cages to a certain limit below which cages are dehydrated and perish. It is necessary to consider that if dehydration of fabrics of plants winter during the autumn period is an important factor of their training and increase morozo-and winter hardiness, the increase in the content of water by the end of the winter period reduces their stability to low temperatures and other adverse phenomena.
For the accounting of a condition of winter crops in their rewintering it is necessary to carry out systematic control. It is important to define in due time vitality of plants in crops, the damage rate and in due time to be prepared by adverse factors for care of plants at renewal of their vegetation, and in case of need, their partial or complete resowing. It is still important and consequently that grades available now summer grain (first of all summer barley), at early crops in so-called "windows" form a grain yield at level of winter crops.
By science it is developed a number of methods of definition of a condition of plants in rewintering: a method of monoliths, (the most available method for farmers of farms of all forms of ownership); water method; sugar method; method of dyes, analysis of cones of increase and fabrics of knots of a kushcheniye. And authentic from them the method of monoliths, a water method, and its updatings are the most reliable.
Method of monoliths. For the analysis of plants at this method select in cm monoliths in the size 30 x 30, in the thickness of 15 cm in typical places of a field on two adjacent ryadka. If the condition of plants on various sites of a field is non-uniform, neobxodimo to select some monoliths so that samples of all groups of plants were presented. For this purpose before winter of a place of selection of monoliths otmechayut landmarks, and for its simplification, on a contour of future monolith it is possible to drive strips of a cardboard or a polyethylene film.
The selected monoliths place in wooden boxes of the corresponding sizes, prikryvayut a sacking, canvas or other heatinsulating material and transportiruyut in a room with temperature not above +5. +10 °C for defrosting. Boxes with monoliths cover with the humidified sacking or other vozdukhoproyonitsayemy material and leave before complete thawing. Usually for this purpose 1-1,5 days are necessary. After thawing monoliths transfer to the warm, well shined room with temperature +7 … +20 °C. Elevated mass of plants cut off scissors at height of 5-7 cm from a soil surface, near walls of boxes the soil condense, and if necessary pour, that emptiness and cracks weren’t formed. A plant polivayut water of room temperature as required, without allowing a monolith peresyyokhaniye. At creation of optimum conditions for growth of plants the predyovaritelny assessment of viability can be carried out in 10 days, and okonchayotelny – in 2-3 weeks.
At an assessment it is necessary to carry the plants forming new leaves and central roots to the viable. It is necessary to note that at underdeveloped plants since autumn, and in the conditions of insufficient lighting, at the beginning and the middle of winter new central roots can not be formed, but at good growth of sheet plates such rasyoteniye should be carried to the viable.
The method of monoliths gives the most authentic characteristic of viability of winter crops under condition of strict observance of all rules of selection, transportation, thawing and an otrashchivaniye of samples. Violation at least odnogoiz them leads to distortion of results.
The Vodnyymetoddayetvozmozhnost of faster assessment a sostoyayoniya of plants, however its reliability is slightly lower, than a method of monoliths. In 2-4 typical places of a field vyrubyvayut plants from two adjacent ryadok on 0,5 running meters. Together with lumps of the earth them defreeze, kakmonolity then separate from the soil and wash water of room temperature. After that at them cut off roots at distance of 3-4 cm, and escapes with leaves on 5-6 cm from kushcheniye knots. Plants place in superficial capacities with water (rastilni, plates) so that they were covered with water on 2-3 cm above the basis of knot of a kushcheniye. Samples expose in well shined room with temperature of 18-20 °C, water neobxodimo to change each 2 days. In 2-3 days appreciable at live plants, and a final assessment it is possible to do growth of leaves and central roots in 7 days. Zhizyonesposobnye plants actively grow, form new leaves and backs, povreyozhdenny grow poorly, and victims don’t form new leaves and roots
Updatings of a water method are the sugar method, a method of the Don scientific research institute of agricultural industry and an express method of Institute of plant growing of V.Ya.Yuryev. Distinctive feature of a sugar method is that instead of water for an otrashchivaniye of plants sugar solution is used. For definition of a condition of plants by an express method the preparatory work is carried out as well as at a water method, with that only a difference that the elevated part of plants is cut off at level of a divergence of leaflets, and by roots – on 1 cm from kushcheniye knot. Thus plants are more compact and convenient to Podgoyotovlennye in work, it is less porazhayutsya a mold and quicker grow. Them place in chemical glasses with water so that water covered the lower part of knots of a kushcheniye, from above cover with glass or a film, expose in well shined room with temperature +24… +26 °C. In a day at live plants the gain of 3-6 mm is observed, victims of a gain don’t give. The final accounting of live plants carry out in three days.
At the "Don" method of an otrashchivaniye at previously prepared plants roots and leaves are cut off at distance of 1,0-1,5 cm from kushcheniye knot. Cut off place in glass jars in capacity of 250-500 ml on which bottom, cotton wool, a gauze or the filtering paper, moistened with water are put.
For creation of high humidity banks close and 16-24 hours maintain in a warm place at temperature 24-26°C. At well remained plants the gain of a stalk makes 10 mm and more, weakened but quite viable have a gain of 3-5 mm. The lost plants don’t grow. The "Don" method of an otrashchivaniye use at Klepinino’s agrometeorological station and consider that on accuracy and reliability it doesn’t concede to a method of monoliths, and allows to define a condition winter in the shortest terms.
Determination of viability of winter plants by this way doesn’t demand the difficult equipment and is available in the conditions of farms.
The method of dyes consists in use of such himiyochesky substances as fuchsin sour and tetrazol. On selected defrozen and otyomyty as at a water method, plants do a longitudinal cut at level of a razmeyoshcheniye of a cone of increase. Cuts place on subject glass and paint a rasyotvor of fuchsin or tetrazola. Fuchsin paints dead fabrics in bright red color, live cages remain slabozelenovaty or colourless. Tetrazol not izmenyaet colors of the lost fabrics, and in live cages under the influence of enzymes obrazuetsya formazin, having bright crimson or cherry color.
The method of biological control (the analysis konusa increase according to F.M.Kuperman) consists in supervision over a cone a narastayoniya under a binocular magnifying glass, previously having opened it from rudiments of leaves. At live plants an increase cone pale green, tourist’s mountain; at victims – differs turgor loss, turbidity, yellowish-brown and koyorichnevy coloring. It is necessary to pay attention also to a condition of fabrics of knots of a kushcheniye. At the damaged plants they gain brown color; the defeat zone is more extensive, the plant is less viable. The death of such plants in the conditions of late or dry spring is especially probable.
On the basis of calculation of the live, weakened and lost plants in tests recalculation per unit of area is carried out them.
It is necessary to note that rewintering of winter crops, their stability to low temperatures substantially depends on high-quality structure. Use of grades not adapted for specific conditions of the region often leads to their death or strong easing. It first of all belongs to rewintering of winter barley and cabbage (a rape, mustard, a brace bit).
Winter wheat as the culture, very much reacts on the predecessors which influence isn’t limited to only autumn growth, and extends on formation of abilities morozo-and winter hardiness. The positive role of the predecessor can be shown by a full measure only under condition of the correct approach to soil processing. The role of processing of the soil in increase of winter hardiness of the winter consists in its main appointment – to create such conditions in an arable layer of earth at which for plants optimum conditions of a water, nutritious, air and thermal mode are provided.
Unfortunately, quite often experts, deciding destiny of a winter wedge, are guided not by calculations and science conclusions, and intuition. Thus sometimes peresevayutsya massifs on which it is possible to expect productivity of 20 c/hectares and more, and those crops which with approach of spring appear lost, peresevayutsya with delay therefore the soil dries up, leave the best terms of sowing summer, and their crop on resowing winter, as a rule, happens much lower, than on zyabi.
Diseases and wreckers of field cultures also have in recent years the negative impact on conditions of rewintering of the winter. The system of protection of the winter should be based on the basic principles organizational and economic, agrotechnical and chemical methods according to the scheme: performance of a complex of zone agrotechnical receptions which create optimum conditions for growth and development of plants and is reduced by possibility of reproduction of wreckers and diseases; use of steady grades, application of chemical means of protection throughout the entire period of vegetation taking into account an economic threshold of injuriousness. One of the most dangerous and widespread wreckers of winter crops the grain ground beetle is considered. It is possible to consider as a zone of injuriousness of the grain ground beetle Krasnogvardeysky, May Day, Dzhankoysky, Saksky, Soviet and Krasnoperekopsky areas where the population percent wreckers often exceeds 42-47 % from total area of crops. The grain ground beetle most intensively breeds at existence on fields of the postharvest remains (straw and grain). The sprouted fruit drop provides with a forage otrozhdayushhixsya larvae before emergence of shoots of the winter grain. Such conditions were created the last two years and consequently it is possible to predict that number of the wrecker vozrastyot several times. A big damage of efficiency of winter wheat, poseyanny before optimum terms, cereal flies who damage the central ear put and at small degree of a kustistost the crop sharply decreases.
F. ADAMEN, doctor of agricultural sciences, academician of UAAN. AP ARK ministry, APP Crimean institute.