Lyange
E.R.
L.N.Gumilyov Eurasian National University, Astana, Kazakhstan
STABILITY OF
GRADES AS THE MAJOR FACTOR OF PROTECTION GRAIN FROM POWDERY MiLDEW (BLUMERIA
GRAMINIS DC.)
As there can not be a united technology of intensive, so
there can not be a united integrated system of protection of plants. The
suitable integration and technology should correspond to each field.
As it is known, the basis of intensive grain producing
consists of grades (group of grades) which are high-yielding and ecologically
adapted to conditions and technologies. The grade and its genetic possibilities
define potential efficiency. For construction of effective protection it is
necessary to know stability of the zoned grades to separate components of a
pathogenic complex. The grade monopolism is dangerous for stability maintenance
agro coenosis to a complex of illnesses and in order to receive
stable yield it is necessary to cultivate not less than 3-4 grades differing on
immune genetic properties. Thus we carry out a role of mutual sanitary
insurance. [1].
So according to the academician of Russian Academy of
Agrarian Sciences V.A.Zaharenko [2], in 2004 from 2686 new studied grades of
agricultural crops only 72, or 2,7 % had complex stability, therefore the
saturation of crops by steady grades is extremely insufficient. However even
the available set of grades of wheat allows to constrain essentially
development of the most dangerous illnesses and by that to reduce pesticide
loading on agrocoenosis. Therefore it is offered to use the highly developed grade
policy, which includes timely grade change, mosaic placing of grades in crop
rotation fields, their alternation in time and space, systematic grade
renovation. In a basis of such approach seeding of the tolerant grades having
complex stability, non-admission of domination of certain race in agrocoenosis,
decrease of harmful organisms and speed of their development lie.
By means of a grade it is possible to solve
successfully not only problems of protection a plant from harmful organisms,
but also questions of resource – saving, less expenditure, ecologically manufactures
of agricultural products. There are two basic directions of practical use of
selective achievements in protection of plants: use of grades genetically
protected from harmful organisms of grades and scientifically valid strategy of
their application based on mosaic placing of grades on agro landscape niches,
proved sort change, use of the grade mixes possessing not related genotypes of
stability.
Cultivation of grades with complex and group stability
to pathogen is a rod element in the integrated protection of plants. However to
combine in one genotype the high stability to pathogen with increase of quantity
and quality of a crop, and improvement of other useful economic signs is an
extremely difficult problem. Growing of
such grades takes on special significance in sanitary zones where application
of pesticides is forbidden.
Grade renovation is a replacement of seeds of one
grade with seeds of the same grade, but higher reproduction (elite, super
elite). Grade renovation allows keeping immunological properties and higher
indicators of efficiency. It is recommended to hold it every 1 or 2 years.
Alternation of grades is a replacement of the grade
which has lost stability to any illness with other grade which is stable
against this disease. It is necessary a regulatory change of grades in
avoidance of accumulation of resistant races. For this purpose scientifically
stated schemes of alternation of the grades, providing damageability of a plant
by wreckers and illnesses are developed and put into practice. Working out and
using in practice the scientifically stated scheme of alternation of grades do
not cause any great difficulties. This way has found a wide circulation in the
advanced farms of Krasnodar territory.
Mosaic of grades is a spatial placing of grades with
different genotypes of stability within a farm, a crop rotation, an agro landscape.
It is also probably a territorial placing of such grades on agro regions –
spatial heterogeneity. While including in mosaic the stable grades it is
considered their productivity, winter hardiness, drought resistance and other
economic valuable signs. Each grade with its positive properties has to
compensate the lack of other grade shown in conditions of production.
Grade mixed crops of winter wheat. In conditions of
production grades of intensive type with high potential of productivity, but
susceptible to one or several kinds of illnesses often are widely adopted. On
such fields the specific structure of pathogens is quickly formed and it leads to
Illness of a plant, consequently to decrease of the crop and expenses for
protection. Reduction of their defeat without application of chemical means is
reached by mixes of the grades and one of them is stable against activators of
the cores diseases. Mixes of grades allow realizing more full a principle of
the self-regulation, meeting the requirements of the integrated protection.
Thus, with competent performance of substantive provisions of a grade policy,
including the high-quality agro technology, it is possible to achieve essential
decrease in development of illnesses, to lower expenses for pesticides to 30 %
and more, to solve questions of increase of productivity, quality of grain and
other economic valuable signs (winter hardiness, drought resistance etc.) with
the minimum expenses of work and power resources [2].
In S.F.Buga and A.G.Iljuk's work [3] optimization of
terms of application fungicide is offered. Authors consider interference and
inter conditionality of relations in system a plant - the owner – pathogen –
environment and they basically guide by the data of monitoring of development
of illnesses, indicators of hydrothermal conditions during previous 5 - 7 days
and the weather forecast conditions for the nearest 7 - 10 days while decision-making
on carrying out fungicide processing. Biological thresholds of injuriousness
represent indicators of development of illness within 0, 5 - 5 % and they depend
on features of development of the activator (frequency and occurrence of
infections) and grade susceptibilities. They are used as criterion of
expediency of application fungicide only in cases when favorable for the
further increase weather conditions are created, causing essential losses of a
crop, therefore it is very important to protect culture at such stage of
development of illness when its restraint will be effective and the period of action
of a preparation will be longer. Efficiency
of processing depends on both toxic action of fungicide and from the speed and
the level of development of illness at the moment of specimen application. The
lower development of illness at the moment of fungicide application is the higher
probability of receiving of optimum biological efficiency. If the specimen is applied
at development of illness above threshold level its biological efficiency can
be not satisfactory. At application of fungicide Alto super for protection against the mealy dew, applied at
development of illness of 4,4 % in the beginning of heading, it has provided
efficiency only within 39,3 – 42,9 % even in conditions when illness has developed
with low speed.
Wheat is one of the most significant and strategically
important agricultural crops from every possible illness and it should have high
scientifically stated level. During planning of wheat protection system from
illnesses organizational - economic, agro technical, chemical and biological
methods are considered. Creation of stable to pathogens grades and hybrids and
their introduction in manufacture occupy a special place. This method is the
most economic efficient as use of the grade stable against the certain
activator of illness or a hybrid will pay back all expenses for its creation in
tens times. According to department of phytopathology and entomology SGI (Selective
genetic institute) on susceptible grades losses can reach from mealy dew from
10 to 20%, on highly susceptible grades from 30 to 40 %. While creating
artificial infectious fields and modeling of conditions of strong plant illness
crop loss is quite probable 100 %, whereas immune grades won't be and stability
won't be deteriorated at all. On a stability indicator – susceptibilities all
grades transferred by selectors are studied, and the steadiest from them are
selected. The way of creation of grades stable against illnesses is real,
economically, and that is the most important, is ecologically favorable,
considerably will improve an ecological state of environment and an end-product
– grains [4].
Many other researchers studied the influence
of macro - and micro fertilizers on change of stability of plants to activators
of powdery mildew. G. T. Spinks [5] bringing in soil salt of lithium
(phosphorus acid, carbonic, and nitrate in concentration 1:30000 to 1:100000)
has received immunes to illness of a plant of wheat whereas nitrate salts of
zinc and lead in concentration 0, 01 – 0, 03 % raised a susceptibility to it. N.I.Vavilov [6] has experimentally
established decrease in a susceptibility of wheat to powdery mildew in the
first phase of development a plant at presence in soil of lithium and the
raised susceptibility a plant at entering into soil of nitrate salts of lead
and zinc.
To the factors defining strengthening of infection a
plant of barley by mealy dew belong a potassium lack, optimum temperature and
sufficient humidity. Increase of stability a plant to illness is observed at
the strengthened potash food. S.R.Shvartsman's supervision [7] establish more
intensive development of powdery mildew on the plants which have been grown up
at sufficient (60 %) water supply, and weak – at insufficient (40 %). It is
noticed that watering of seeds in solutions of salts cobalt, iron, and
manganese in a combination with extra root additional fertilizing the same
microcells raises stability of barley to mealy dew.
In the conditions of Bulgaria entering of one nitric
fertilizer sharply strengthens, and pre-seedy entering of phosphoric and potash
fertilizers appreciably reduces illness of plant of mealy dew of crops of
barley and wheat. Its reason is increase in quantity of mechanical elements in
walls of plant cages. Glynne Mary [8] also marks efficiency of potash
fertilizer in struggle against mealy dew of wheat. F.T.Last [9] has established
that nitric fertilizer reduces, and phosphoric one raises stability of plants
to illness.
In struggle against activators mealy dew illnesses
sulfuric preparations give positive results. In struggle against powdery mildew
of barley sodium sulfate soda, drill, magnesium sulfate in solutions of the
concentration of 3% with addition of sticking substances are effective. At
regular fumigation illness development on wheat shoots is late with an interval
of 10-12 days for 8 weeks is late.
Thus, it is possible to draw following conclusions
that the effective way of protection of plants from mushroom diseases,
including mealy dew is first of all creation highly stable grades to the complex
pathogens. This method has a lot of advantages: it has the high biological
efficiency and it is ecologically defensible and self-supporting. Processing fungicides
has important value in protection of a plant, but it requires keeping of
processing terms, the good forecast of a complex pathogens on the given site
and efficiency and treatment constrain development of several strongly active pathogens.
Timely and rational entering fertilizer, a crop rotation of different cultures
influences development and injuriousness powdery mildew as well. A correct
planning of protection guarantees a big crop and quality of grain.
References
1. Sanin S.S. The role of a grade in the integrated
protection of grain crops//Protection and quarantine of plants 2007. ¹3 P.16
- 19.
2. Zazimko M.I., Fetisov D.P., Egorov S.S., Malyhina
A.N. The role of a grade in winter wheat protection//Protection and quarantine
of plants 2008. ¹ 6.- P.11-13.
3. Bug S.F., Iljuk A.G. Optimization of terms of
application fungicides and an economic return on protection of winter wheat
against illnesses in Belarus // Protection and quarantine of plants 2009, ¹5,
P. 41 52
4. BabajantsO.V, BabajantsL.T., BushuljanM.A,
TraskovetskayaV.À, BaranovskayaV.L., VasilevA.A., DubininaL.A., ZaloginaM. A,
Pljasny V. A, Nikiforova E.A. Selection of wheat on complex stability – as the
factor of ecological protection//Collection of articles. International
scientific conference «Actual problems of studying phyto – and microbiots» Minsk,
2004.-P.127-128.
5. Spinks G.T. Factors affecting susceptibility to
disease in plants. «Journal of agric». Sc VOL.5. - Part.3.-P.231.
6. Vavilov N.I. Immunity of plants to infectious
diseases//News of Petrovsky Agricultural Academy, 1919.
7. Øâàðöìàí S.R. Influence of conditions of a root
food on a current of disease of wheat caused by mealy dew//Works of institute
of Botany of Academy of Science KazSSR. Alma-Ata, 1961.-V.9.
8. Glynne Mary. Effect of potash on powdery mildem in
wheat. «Plant pathol.», 8.1959. ¹ 1.
9. Last F.T. Analisis of effect of Erysiphe graminis
D.C. on the growth of barley. «Ann. Bot.» 26, 1962. ¹ 102. P.279-289.