
POSSIBILITIES OF THE BIOLOGICAL METHOD OF COTTON PLANT PROTECTION IN UZBEKISTAN
1.Introduction. As it is known, generally recognized and widely used in many countries of the world including Uzbekistan, the so-called integrated system of plants protection (ISPP) provides carrying out of such tactics of plants protection at which number (density) of the pest(s) restrains at economic-harmless level, practically reducing their number to criterion of economic thresholds of harmful number (ETH). Control levers of such system are all possible methods, to some extent capable to lower the number of harmful organisms (organizational-economic, agro technical, mechanical, selective, genetic, biological, chemical, etc.) to economic imperceptible level. Hence, a biological method of protection of plants calculated on efficiency of not only artificially flooded bio agents (trichogramma, bracon, lacewing, etc.), but also on natural self-control of arthropods animals, is being one of the elements of ISPP. And as value of this method is great, the method of biological protection of plants is one of the basic and solving in ISPP [1-4]. Nevertheless, it is impossible to forget, that it is only one of protection methods of ISPP elements and that it is not all-powerful [6]. There are results of numerous experiences which say that in natural conditions the entomophages seldom destroy their victim on 100 %. At least for this purpose coincidence of two factors is necessary: high density and vital indicators of one or several target entomophages and adversity of climatic conditions for successful development of a harmful organism.
2. Materials and Methods. Work was spent in the Andizhan area of Uzbekistan. In work methods of laboratory raring and application of entomophages [7, 8] have been used. Accounts of insects were spent according to methodical instructions [9].
Definition of optimum terms of trichogrammas outlets was made on signals of pheromone traps given by institute of bio organic chemistry of Academy of sciences of the Republic of Uzbekistan [10].
3. Results and Discussion. In the Andizhan area, after a long depressive for development of cotton columbine borer (Helicoverpa armigera Hb.) years, in 2007 and 2008 a mass development of this pest at flash level was observed. In 2007 in economies of Balikchin area the series of experiences for efficiency studying of trichogramma (Trichogramma pintoi) and bracon (Bracon hebetor), reared in local bio laboratories, and also brought from bio factory of Tashkent state agrarian university (ТSAU) have been spent. In the table schemes of experience variants are resulted: efficiency of trichogramma (on indexes of eggs infection rate), and also of bracon on infection of cotton borers caterpillars.
From the received results follows, that low results were shown at use of laboratory reared bio agents. At natural fertility (sterility) of eggs at level of 35-41 % and natural infection of eggs by trichogramma – 2,1-3,7 % (control-I), local population of a parasite has shown only efficiency at level of 13,2-21,2 %, and made in ТSAU was better, but also that only made 24,3-44,3 %.
Dependence of effectiveness of trichogramma and bracon versus cotton borers on their quality
Production experience, the Andizhan area, 22.07-09.08.2007
№
Experience variants
Infection %% on days:
Eggs
Caterpillars
3
6
9
3
6
9
1.
Trichogramma (local population) – 3 multiple outlet
13,2
21,2
16,5
-
-
-
2.
Trichogramma (ТSAU) – 3 multiple outlet
24,3
37,2
44,3
-
-
-
3.
Control-I (Natural infection of eggs by trichogramma)
2,1
3,3
3,7
-
-
-
4.
Control-II (Natural sterility of eggs)
41,5
36,1
35,0
-
-
-
5.
Bracon (local population)-2-multiple outlet in 1:15-20. The general norm of outlets 5000 ex/ha
-
-
-
17,5
34,2
30,5
6.
Bracon (ТSAU)- 2-multiple outlet in 1:15-20. The general norm of outlets 5000 ex/ha
-
-
-
21,4
45,4
47,2
7.
The control (naturally)
-
-
-
3,4
11,2
7,3
The number of cotton borers’ caterpillars was so high that it was necessary to let out unusually considerable quantity of bracon – 5000 ex/ha. The results also have shown, that local populations of this parasite are less effective – 17,5-34,2 % within 9 days after 2 let outs, and from ТSAU, accordingly – 21,4-47,2 %.
Approximately the same results have been received at another our experience spent in 2006 in the conditions of the Andizhan area. Thus, it is possible to conclude, that carrying out of biological control against cotton borers with the help of trichogramma and bracon are justified on sites with moderate number of the pests in limits till 20-25 eggs and caterpillars on 100 plants on the average. In cases of mass reproduction of cotton borers it is expediently to use insecticide protection. Thus, the efficiency of a method will depend again on correctness of selection of the scientifically-proved terms of processing carried out.
Namely, it will be effective in overwhelming cases only when it coincides with the moment of mass oviposition and pests’ caterpillars’ birth. These terms can be defined only by frequent qualified accounts of observers – keepers with involvement of the control of pheromone method.
Special interest in a biological method of plants protection represents raring and application of predatory lacewings (fam. Chrysopidae). As it is known in agro biocenosis of the Republic are living over 10 kinds of chrysopas [5]. Among kinds dominate: ordinary lacewings– Chrysopa carnea Steph., seven-dot – Ch. septempunctata Wesm. And beautiful one – Ch. formosa Br.
Lacewing is the predator-polyphage destroying representatives of many kinds of arthropods animals in biotops with crops. To it are peculiar a number of the merits favourably distinguishing it from others entomophages. But at the same time, there are also the lacks constraining its wider use, than it now is. So, that is its nature – an expressed cannibalism in a stage of larvae development. It essentially brakes the process of laboratory raring of a kind. And the mechanized process of reproduction based on individual development of individuals with use of ANM (artificial nutritious means) –is expensive and economically unprofitable [5].
In Uzbekistan a technique of laboratory cultivation of lacewings on eggs of cytotroge and outlet of a predator on fields in a phase of eggs and imago is adjusted [8]. How much effective and profitable this technique is? Considering results of numerous experiments which have shown, that lacewing is effective at outlet of its larvae in parities to victims 1:10-15, it is possible to ascertain, that one lacewing is not enough to reach efficiency. First because it is impossible to get such necessary quantity of larvae in laboratories; secondly, the eggs settled on fields become easy extraction of ants, and also of secondary parasites (accounts have shown, that in June on cotton fields of the Fergana area it is possible to count about 350 ants on м2). Thirdly, it can manage very expensively in financial expression.
There are two ways of practical use of laboratory reared lacewing. The first – early (spring) enrichment of boundaries, roadsides, alfalfa fields and early crops and the second – local use of the big norms of entomophages let out on the early-spring covered vegetable sowings and in hothouses with advantage of outlet of larvae of a predator in parities 1:10-15 to victims, and also imago – for enrichment of concrete agro biocenosis.
In any case, use of a biological method of cotton plant protection from cotton borer and other kinds of it in the conditions of Uzbekistan is economically and ecologically demanded, for only it promoted to reduce frequency rate of chemical processings from 10-12 (till 1980) to 0,7-1,3 (2008-2009).
4.Conclusions. In Uzbekistan the biological method of cotton protection from cotton borers (Helicoverpa armigera Hb) and other kinds of borers is widely used. In these purposes are used: against eggs – trichogramma (Tr. pintoi, Tr. evanesens), caterpillars – bracon (Br. hebetor). Stations enrich by lacewing (Chrysopidae). By experiences it is established, that biological effectiveness of trichogramma against borers in strong degree depends on their quality and can make from 13,2-21,2 % to 24,3-44,3 %, and bracon – from 17,5-34,2 % to 21,4-47,2 %.
References
1. Viktorov G. A. Principles and methods of the integrated pest control of agricultural crops//Biol. means of plants protection. – М: Kolos, 1974. – p. 11-20.
2. Narzikulov M. N, Umarov Sh.А. Not to mow, as a plait, and to strike, as a sword//Protection of plants. – 1980. – №1. – p. 17-19.
3. Kan А.А., Кiм Ch.N. Integrated cotton plant protection against pests. – Tashkent: Меhnаt, 1988. – p.76.
4. Uspensky F.M., and others. System of integrated pest control of cotton plant. – Tashkent: Fan, 1969. – p. 89-100.
5. Radzilovskaya M.A. Lacewing against a plants aphid on a cotton//Protection of plants. – 1980. – №10. – p. 26.
6. Hodzhaev S.T., Jusupova M. N, Kuryasov Sh.,Sattarov N. Perspectives of biological protection of a cotton from cotton borers// Works. – Tashkent: Таlkin, 2008. – p. 44-49 (Uzb.).
7. Alimuhamedov S.N., Adashkevich B.P., Adylov Z.K., Khodjaev SH.T. Biological method of cotton plant protection – Tashkent: Меkhnat, 1990. – p. 172(Uzb.).
8. Мirzaeva H.R. Biological method of pest control of agricultural crops. – Tashkent: Маtbuot, 1986. –p. 54.
9. Methodical instructions on test of pesticides. – Tashkent, 2004. –p. 103.
10. Methodical instructions on application of pheromones for definition of terms of trichogrammas outlet ( S.T.Hodzhaev, etc.) – Tashkent, 1984. – p.5.
About the Author
Kuyganyor town, Andizhan area, Andizhan district, Uzbekistan.
ph:(+99874) 222-17-84
Fax (+99874)373-13-63
e-mail: maxpuza-70@mail.ru
Yusupova Maxpuza
“India Nature: Kutch Backroads, An Essay, part I” Lraleigh’s photos around Tera, India
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