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Discoveries in Agriculture and Food Sciences - Vol. 12, No. 6
Publication Date: December 25, 2024
DOI:10.14738/dafs.126.17851.
Latibovna, I. M., Nimatovich, R. B., Bobomurotovich, A. D., Isaevich, M. S., & Chorievich, G. I. (2024). Influence of "Composite
Defoliant" on Cotton Crop Yield and the Environment. Discoveries in Agriculture and Food Sciences, 12(6). 89-104.
Services for Science and Education – United Kingdom
Influence of "Composite Defoliant" on Cotton Crop Yield and the
Environment
Ikramova Makhbuba Latibovna
ORCID: 0000-0001-8880- 131x
Scientific Research Institute for Seed Breeding and Agricultural
Texnology of Cotton Growing, Bukhara Scientific Experimental
Station, No. 309, B. Nakshband, Bukhara, 200100, Uzbekistan
Rakhmatov Baxtiyor Nimatovich
ORCID: 0000-0002-9669-4451
Scientific Research Institute for Seed Breeding and Agricultural
Texnology of Cotton Growing, Bukhara Scientific Experimental
Station, No. 309, B. Nakshband, Bukhara, 200100, Uzbekistan
Allaqulov Davlat Bobomurotovich
Scientific Research Institute for Seed Breeding and Agricultural
Texnology of Cotton Growing, Bukhara Scientific Experimental
Station, No. 309, B. Nakshband, Bukhara, 200100, Uzbekistan
Maxsudov Saidumar Isaevich
Scientific Research Institute for Seed Breeding and Agricultural
Texnology of Cotton Growing, Bukhara Scientific Experimental
Station, No. 309, B. Nakshband, Bukhara, 200100, Uzbekistan
Gaffarov Inoyat Chorievich
Scientific Research Institute for Seed Breeding and Agricultural
Texnology of Cotton Growing, Bukhara Scientific Experimental
Station, No. 309, B. Nakshband, Bukhara, 200100, Uzbekistan
ABSTRACT
The data on the use of "composite defoliant" influence on the rate of opening of the
boll, leaf fall, the share of the first harvest of raw cotton are presented. The aim of
the study is to reduce the doses of the defoliant Mg (ClO3) 2 Liquid by 50%, by adding
Fitovak + Urea + humin, turning it into a mild defoliant, to increase the rate of
opening of bolls, the share of the first harvest, the quality of cotton, protecting the
soil and the atmosphere of the environment from various harmful salts. The objects
of the study were the varieties "Bukhara-8", "Bukhara-10" in the conditions of
moderately saline soils of the Bukhara region. Fitovak + Mg (ClO3) 2 Liquid + urea +
humin was comprehensively defoliated, which has a strong effect at different times
of opening of bolls by 20-30; 30-40, 40-50%. The conditions, methods of research in
saline soils of the Bukhara region, the timing of the application of the "composite
defoliant" depending on external factors in field and laboratory conditions were
studied. The studied data proved that among the studied 2 varieties, with different
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Discoveries in Agriculture and Food Sciences (DAFS) Vol 12, Issue 6, December- 2024
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terms of opening of bolls, the best indicators were 10-11-12-variants. In terms of
the rate of ripening of bolls, the differences compared to the control for two
varieties, respectively, were: by + 29.7-25.5-25.3%; +30.9-29.2-22.8%. The increase
in the 1st cotton harvest was respectively: +10.0 +12.3 +10.7 c/ha (Bukhara-8) +6.3
+13.4 +11.7 c/ha (Bukhara-10) and was higher than the control.
Keywords: "composite defoliant", three terms of boll opening, opening rate, share of the
first cotton harvest, efficiency, environmental ecology, seed and fiber quality.
INTRODUCTION
Currently, a fundamentally new direction is being formed in agricultural culture in the search
and development of pesticides, universally acting, multi-purpose stimulants of protective
reactions, growth and development of cotton, which simultaneously perform many functions.
Since they form induced resistance to pathogens, stimulate formative processes, increase the
activity of photosynthesis, and increase the quantitative and qualitative indicators of the crop
yield [1- 3]; [4- 6]; [7-9].
In the Republic of Uzbekistan, for many decades, various pesticides have been used in full- recommended doses of consumption depending on the goals and objectives of agricultural
crops to destroy various pests, diseases, weeds and defoliate. In this regard, toxic compounds
accumulated in the environment and in the atmosphere from year to year, and the quality of
the crop yield decreased. In addition, the use of multiple and high doses of pesticides had a
negative impact on the cost of production and the ecology of the environment.
An alternative, complex immune- and growth-stimulating regulator is the immune stimulant -
"Fitovak". It is based on the management of the physiological reactions of the plant itself and
increasing its seasonal resistance until the end of the vegetation period of plants. [1- 3]; [4- 6].
When treating plants with "Fitovak", protective mechanisms increase, which leads to an
increase in the activity of phytoalexin induction, which is a trigger for the protective reaction of
hypersensitivity of infected cells.
"Fitovak" acts on cotton as an immunizer even before its contact with the pathogen and
promotes temporary physiological regulation of the genetically determined property of cotton
resistance. It is especially irreplaceable in years with poor climatic weather conditions, has a
rehabilitation capacity on problematic cotton plants, and has a beneficial effect on physiological
and biochemical processes, thereby accelerating ripening and increasing the yield and quality
of fiber [1- 3]; [4- 6]; [7-9].
The works of P. Kinta [7] determined that many bio regulators exhibit membrane-active
properties, due to which the possibility of their use in combination with pesticides opens up.
Due to the increase in the permeability of cell membranes caused by the use of bio and immune
stimulants, the possibility opens up to reduce the doses of consumption and the number of
treatments with chemicals, i.e. to reduce the "pesticide pressure" on the environment.
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Latibovna, I. M., Nimatovich, R. B., Bobomurotovich, A. D., Isaevich, M. S., & Chorievich, G. I. (2024). Influence of "Composite Defoliant" on Cotton
Crop Yield and the Environment. Discoveries in Agriculture and Food Sciences, 12(6). 89-104.
URL: http://dx.doi.org/10.14738/dafs.126.17851
In the field of biotechnology, Uzbek scientists have conducted a number of important studies,
and taking into account the above-mentioned works of Kinta, by adding immune stimulants,
holmic substances and mineral fertilizers to defoliants in a complex, which have a positive effect
on the growth and development of plants, increase productivity, resistance to various diseases
and pests, and have a strong effect. [4]; [7-9]; [10-11].
As a result, the doses of pesticides and defoliants are reduced by 40-50%. These universal
composite compounds, which reduce consumption rates and increase the effectiveness of
defoliants, have a positive effect on the weight of one boll and the quality of cotton, turning a
harsh defoliant into a mild one. Among such stimulants + defoliants include: Mg (ClO3)2 Liquid +
Hosil; Mg (ClO3)2 Liquid + Rostbisol; N-dimethylaminomethyl-N, N-demethylammonium oxalate
(DDO) + Mg (ClO3)2; Mg (ClO3)2 Liquid+ Fitovac; Mg (ClO3)2 Liquid. + Fitovak+ Urea + Humin, etc.
Complex use of the preparation "Fitovak" with mineral fertilizers, humic acid salts and
defoliants, as well as herbicides, pesticides and other chemical preparations makes it possible
to reduce the norms used in production by half. This provides savings of 50% without reducing
the effect of expensive preparations [4].
Application on meadow-alluvial, saline soils of the Bukhara region based on the prepared
"composite defoliant" in a tank mixture, which includes "Fitovak" 75 ml + urea 6.5 kg + humin
- 1.5 kg / ha + liquid magnesium chlorate 4 l / ha, various opening (by 20-30; 30-40; 45-50%)
of cotton bolls is very relevant.
Simultaneous use of the "composite defoliant" reduces the number of treatments and doses of
pesticides, increases the weight of one boll, the rate of opening of bolls, the share of the first
harvest and the quality of cotton, and reduces the accumulation of chlorine and other toxic
substances in the soil. To prepare a universal and contact-acting “composite defoliant” from
“Fitovak”, 75 ml/ha is taken from the recommended dose of 200-300 ml/ha, adding humic
compounds (1.5 kg/ha) and urea (6.5 kg/ha) in physical state and liquid magnesium chlorate 4
l/ha). By introducing this solution, we can reduce the recommended rate of magnesium
chlorate (8 l/ha) by two times (4 l/ha) and transform a hard-acting defoliant into a soft-acting
one. In the conditions of the Bukhara region, spraying defoliants on the Bukhara-8 and
Bukhara-10 cotton varieties with the addition of harsh liquid magnesium chlorate and Fitovak
stimulants, urea and humic substances in different rates during the period of three terms (20-
30; 30-40; 40-50%) of cotton opening is being studied for the first time.
How it affects the early maturity of cotton, the rate of boll opening, what is the proportion of
the first harvest, the weight of one boll, the quality of the fiber, the oil content of the seeds and
how it affects the environment during the period of using the "composite defoliant" to increase
its effectiveness has not been thoroughly studied on a scientific basis and no recommendations
for production have been given. Taking this into account, it is very important to conduct
scientific work on this topic in the saline meadow-alluvial, soil and climatic conditions of the
Bukhara region.
The object and subject of the research were - liquid magnesium chlorate defoliant, immune
stimulant Fitovak + Urea + Humin, mid-season Bukhara-8 and early-season Bukhara-10 cotton
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varieties, in meadow-alluvial, saline soil conditions with 3 different openings (20-30; 30-40;
40-50%) of cotton bolls.
The purpose and objectives of the study. To determine the optimal timing of the application of
the "Composite defoliant" by adding liquid magnesium chlorate in optimal rates of Fitovak +
Humin + Urea, which has a strong effect on mid-season Bukhara-8 and early-season Bukhara- 10 cotton varieties, on meadow-alluvial soils of the Bukhara region prone to salinization. To
determine the rate of boll opening, reduce the rate of defoliant use, increase the efficiency of
defoliants and crop quality, and provide recommendations for production.
RESEARCH METHODOLOGIES
The optimal terms of the "Composite defoliant" with a universal property of action in saline,
meadow-alluvial soils of the Research Institute of Selection, Seed Production and Cultivation of
Agro technology of Cotton of the Bukhara Scientific Experimental Station were studied in field
and laboratory conditions.
The study was conducted according to the methodology adopted by the Research Institute of
Selection, Seed Production and Cultivation of Agro technology of Cotton "Methodology for
conducting field studies" [12].
"Methodological guidelines for state testing of cotton defoliants" [13-15].
The obtained yield data were analyzed by the dispersion method based on the manual
"Methodology of Field Experiment" [16] by B. Dospekhov.
Methodology of agrochemical, agrophysical and microbiological studies of field cotton regions
[17], the leaf surface, biomass and productivity of photosynthesis were determined during the
growing season of cotton: with the appearance of 2-4 true leaves; budding; flowering; and
ripening according to the Tretyakov method [18].
A study was conducted on the effectiveness of a composite defoliant in an experimental farm
(2021-2023) of the Research Institute of Selection, Seed Production and Cultivation of Cotton
Agro technology of the Bukhara Scientific Experimental Station.
In order to reduce the rate of chemical defoliants and increase the effectiveness of the defoliant,
increase the share of the 1st harvest, the weight of one cotton bolls, and ultimately improve the
ecology, dry mass and productivity of photosynthesis, gross harvest and fiber quality.
The depth of groundwater was 2.0-2.5 m above sea level. The experiment studied 12 variants
from each variety. There are 24 varieties in total, with different degrees of opening of cotton
bolls (20-30; 30-40; 40-50%) depending on external factors, mid-season varieties Bukhara-8
and early-ripening varieties Bukhara-10.
Irrigation in the experiments was stopped 14 days before the use of defoliants. The
effectiveness of the composite mixture was judged by the number of fallen leaves on the 7th
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Latibovna, I. M., Nimatovich, R. B., Bobomurotovich, A. D., Isaevich, M. S., & Chorievich, G. I. (2024). Influence of "Composite Defoliant" on Cotton
Crop Yield and the Environment. Discoveries in Agriculture and Food Sciences, 12(6). 89-104.
URL: http://dx.doi.org/10.14738/dafs.126.17851
and 14th days after treatment. When conducting the counts, the number of green, dry leaves
remaining on the plant was counted. At the same time, the effect of the composite mixture on
the intensity of boll opening was determined. Harvesting was carried out manually from the
entire area of the plot.
In the experiments, plant spraying was carried out using a manual knapsack sprayer at a
working fluid consumption rate of 900-1000 l / ha. The area of each plot is 90 m. The control
background was cotton plants untreated with defoliants. The reference variant was a harsh
defoliant - Mg (ClO3)2 Liquid -8 l / ha; a mild defoliant - Entodefol 150 ml / ha.
The experiment was repeated three times. The size of each variant (3.6 x 20 m) 72 m2. The total
plots for the variants and replicates were 2592 m2 for mid-season Bukhara-8 and 2592 m2 for
early-season Bukhara-10. In total, the accounting plots were 5184 m2. The experimental
variants are arranged according to the randomization method.
All agro technical measures in the experimental fields were carried out according to the plan
developed by the experimental farm. The experimental scheme is given in Table 1.
Table 1: Experiment scheme
Experiment options Cotton
varieties
application doses, ml/ha,
l/ha, kg/ha
Boll opening,
%
1
2
3
4
5
6
7
8
9
10
11
12
Control (Defoliation is not
carried out)
Mid-season Bukhara-8
Early ripening Bukhara-10
0,0
20-30
30-40
40-50
(Standard) Magnesium
Chlorate liquid 8 l/ha
20-30
30-40
40-50
(Standard) Entodefol 150 ml/ha
20-30
30-40
40-50
Mg (ClO3)2 liquid + Phytovac +
Urea + Humin
4 l/ha + 75 ml/ha +
6,5 kg/ ha + 1,5kg/ ha
20-30
30-40
40-50
According to the generally accepted methodology developed by scientists at the Research
Institute of Selection, Seed Production and Cultivation of Cotton Agro technology of the Bukhara
Scientific Experimental Station, field germination and seed germination energy were
determined, phrenological records were taken, and the growth and development of cotton was
observed. Soil samples were taken in two periods - (at the beginning) in spring and (at the end
of the growing season) in autumn at the 0-30; 30-60; 70-100 cm soil layer horizons for
agrochemical and melioration analyses.
Before and after defoliation (after 7 and 14 days of treatment for up to 3 weeks), biological
conditions of cotton were recorded for all variants. The following were counted: plant height,
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number of fruit branches, number of leaves, including green, semi-dried, dried and fallen leaves,
as well as the number of mature bolls, including open and semi-open ones.
At the end of the growing season, manual collections and records were made to determine the
yield of plants. The fiber quality was determined in the «SIFAT» laboratory; the oil content of
the seeds was determined by extraction with petroleum ether on a Sox let apparatus.
Scientific novelty of the work: for the first time, the efficiency of the defoliant Liquid Magnesium
Chlorate was studied together with Fitovak + urea + humin, in various boll openings of 20-30,
30-40, 40-50% on mid-season Bukhara-8 and early-ripening Bukhara-10 cotton varieties on
saline, meadow-alluvial soils of the Bukhara region.
It was also scientifically established that the combined use of the "composite defoliant" had a
positive effect on reducing the recommended consumption rate of liquid magnesium chlorate
by 50%, turning a harsh defoliant into a mild one. Also, the rate of opening of the capsules, the
share of the first harvest, the increase in the weight of one capsule, the mass, quality of the crop
and seeds, the ecological situation and its economic efficiency were determined.
RESULTS AND DISCUSSIONS
For many decades, the main defoliant used in Uzbekistan for pre-harvest leaf fall is Mg (ClO3)2,
which is used at consumption rates of 8-12 kg / ha. The defoliant has a "hard nature" of action.
In this regard, severe burns of young bolls of the upper tier of cotton are often noted, which
leads to losses in cotton yield and consumption rates have a negative impact on the ecological
environment of the republic due to more intense chloride salts in the soil and "pesticide
pressure" on the external environment.
In recent years, many attempts have been made to "soften" the nature of the action of this
defoliant and reduce its negative impact on the environment without reducing the defoliating
effect.
The solution to this problem was developed in several directions: replacing another
preparative form of defoliants that soften their effect or help reduce the dose of defoliants. As
a result of these studies, the following defoliants appeared: Sadaf, Mezon, Sardor, Sihat, etc. [19;
20]. However, all these defoliating compositions, although they softened the effect of the main
defoliant, did not reduce or slightly reduced the rate of defoliant consumption per hectare.
The use of this composite defoliant -(Mg (ClO3)2liquid + Fitovac + Urea + Humin) made it possible
to obtain a defoliating effect at the level of using magnesium chlorate (powdered) and liquid
magnesium chlorate, applied at a rate of 10-12 kg / ha, 8-10 l / ha, there were no burns of young
capsules.
The biological condition of the plant before defoliation (in 2021-2022-2023) at three different
times of boll opening (by 20-30; 30-40; 40-50%) in both cotton varieties were sprayed by year
in the period: 20.08; 27.08; 4.09 (2021); 10.08; 17.08; 24.08 (2022); 8.08; 16.08; 23.08. (2023).
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Latibovna, I. M., Nimatovich, R. B., Bobomurotovich, A. D., Isaevich, M. S., & Chorievich, G. I. (2024). Influence of "Composite Defoliant" on Cotton
Crop Yield and the Environment. Discoveries in Agriculture and Food Sciences, 12(6). 89-104.
URL: http://dx.doi.org/10.14738/dafs.126.17851
The average plant height for the variants of the cotton varieties Bukhara-8 and Bukhara-10,
respectively, varied within the range: 97.5 - 102.2 cm; (2021); 98.3-105.18 cm; (2022); 101.6-
102.8 cm; (2023).
Also the number of leaves is 45-70.4; (2022); 60.5-64.6 pcs./plant. (2023); Fruit branches -
15.2-16.4 pcs./bush (2022); 16.8-16.4 pcs./bush (2023); The number of bolls (15.2-21.4
pcs./bush (2022); 18.3-19.7 pcs./bush (2023), Of which the number of opened bolls by year
was respectively: from 4 to 7.5 (Buh-8), 6-9.4 pcs./bush. (Buh-10) in 2022; from 4.5 to 9.2 (Buh- 8), 4.7-9.8 pcs./bush. (Buh-8) in 2023 cotton bolls;
Fitovak, which is part of the composite defoliant, is also an immuno- and growth stimulant. And
in its structure, it is similar to N-dimethylaminomethyl-N, N-demethylammonium oxalate
("DDO") and Rostbisol, and we decided to conduct research with this drug in this direction. In
connection with in view of the above, in 2021-2023 we conducted research to study the
possibility of using a composite defoliant (4 l/ha Mg (ClO3)2liquid +75 ml/ha Fitovak + 6.5 kg/ha
Urea + 1.5 kg/ha Humin).
Usually, Mg (ClO3)2liquid has a “harsh nature” of action, and therefore severe burns of young bolls
of the upper tier of cotton are often noted, which leads to yield losses (the weight of one boll
and seeds decreases, cotton fibers do not fully ripen).
Adding half the rate (4 l/ha) of Mg (ClO3)2liquid to the defoliant at the rate of Fitovak 75 ml + Urea
6.5 kg + Humin 1.5 kg/ha in a tank mixture allows you to turn the composite defoliant into a
mild one. Although we started defoliating cotton early, when the cotton bolls opened by 20-30,
30-40 and 40-50%, we did not observe severe burns of young and mature bolls of the upper
tier of cotton at any time of cotton boll opening.
Based on the results of studies, as an additive to the defoliant Mg (ClO3) 2 liquid introduction at
the rate of Fitovak 75 ml + Urea 6.5 kg + humin 1.5 kg / ha, allows to halve the hectare dose of
Mg (ClO3)2 liquid 4 l / ha, without reducing the defoliating activity of the tank mixture compared
to the use of defoliant at the recommended dose of Mg (ClO3)2 liquid 8 l / ha.
This use of a tank mixture (Fitovak 75 ml + Urea 6.5 kg + humin 1.5 kg/ha) will significantly
reduce the “pesticide pressure” on the soil and improve the environmental situation in the
region.
Where the composite defoliant was used (in variants 10-11-12) in 3 terms of opening of cotton
bolls, a completely different picture was observed, i.e. it had a positive effect on the weight of
one boll, the quality of the fiber, on the oil content of the seeds and led to a decrease in chloride
salts.
The results of the survey (2022), carried out before the use of the "composite defoliant" showed
that, in the treated area, the number of leaves on average per plant fluctuated for the Bukhara- 8 variety from 43.2.2 to 47.7 pcs, and for the Bukhara-10 cotton variety, respectively, it was:
67.1-75.2 pcs. / bush.
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Experimental data (2022) indicate that the defoliating activity of the mildly acting reference
variant Entodefol 150 ml / ha two weeks after treatment at different times of capsule opening
(Bukhara-8 and Bukhara-10), respectively, leaf fall was on average 86.6-87.2-86.7%; and 85.7-
89.2-85.4%.
In these tested composite variants, leaf fall compared to the reference variant, the difference
was not very large, but the percentage of acceleration of ripening and increase in capsule
weight, yield and quality indicators were greater than the reference, control variants.
Depending on the application of the "Composite defoliant" at different times of boll opening in
each cotton variety (Bukhara-8 and Bukhara-10), 3-year studies showed that the percentage of
leaf fall in the 10-11-12 variants by 2022, respectively, was: 85.3-86.4-84.7% (Bukhara-8);
81.6-84.8-83.6% (Bukhara-10). After defoliation (after 14 days), the leaves did not dry out, fell
semi-dry, did not cause severe burns to young and immature cotton bolls, and the weed
infestation of the crop was less than that of the strictly acting reference (4-5-6) variants.
In addition, leafy plants improved row ventilation, and also had a beneficial effect on the rate
of ripening of cotton bolls in two varieties.
In the 10-11-12 variant of using a composite defoliant at different boll openings, due to leaf fall
and, consequently, redistribution of the flow of nutrients and greater access of the sun to the
cotton bolls, the latter began to open faster.
Graphs 1 and 2 shows the impact on leaf fall, bolls opening percentage and first harvest share,
yield addition of the Bukhara-8 and Bukhara-10 varieties in 2022.
The effect of the composite defoliant on leaf fall in both varieties (2023) is shown in Table 2.
Graph 1
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7 8 9 10 11 12
leaf fall,%
opining of cotton
bolls,%
first harvest yield,s/ha
yield increase,s/ha
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Latibovna, I. M., Nimatovich, R. B., Bobomurotovich, A. D., Isaevich, M. S., & Chorievich, G. I. (2024). Influence of "Composite Defoliant" on Cotton
Crop Yield and the Environment. Discoveries in Agriculture and Food Sciences, 12(6). 89-104.
URL: http://dx.doi.org/10.14738/dafs.126.17851
Graph 2
The results of the accounting carried out before the use of the composite mixture showed that
in the treated area the number of leaves of one plant on average ranged from 52.2 to 67.7 pcs.
(Bukhara-8); 60.1-71.5 pcs/per bush (Bukhara-10), (Table2). As the data in Table 2 show, the
defoliating activity of Mg (ClO3)2liquid -8 l/ha and Entodefol 150 ml/ha throughout the
experiment, the indicators were almost identical. Accordingly, the leaf fall for the two varieties
was: (88.1-90.8-87.8%; 81.9-80.8-78.5% (Bukhara-8); 81.4-85.4-83.7; 82.5-89.2-95.4%
(Bukhara-10).
Addition to half the rate of defoliant in the amount of 4 l/ha Mg (ClO3)2 liquid + "Fitovak" 75 ml/ha
+ Urea (6.5 kg/ha) + Humic substances (1.5 kg/ha) after only 14 days the amount of fallen
leaves from plants of both varieties of cotton varied within the range of 80.1-77.6-84.7%
(Bukhara-8); 81.0-84.8-80.5% (Bukhara-10).
Table 2: Effect composite defoliant for leaf fall and cotton boll opening in the Bukhara
region
Options
cotton
boll
opening,
%
Average number of leaves,
pcs./bush
Number
of cot- ton bolls,
pcs./
bush
Including opened
Before
treatment,
pcs./
bush
2 weeks after
treatment
Before
treatment
2 weeks after treatment
pcs./
bush
defoliation
efficiency,
%
pcs./
bush
% pcs./
bush %
Rate of
disclosure,
% (to
control).
Mid-season cotton variety Bukhara-8 (2023)
1
Control, 00
20-30 52.2 48 8.04 17.3 4.5 26.0 9.6 55.5 0.0
2 30-40 62.0 56 9.77 18.0 6.8 37.0 12.0 66.7 0.0
3 40-50 63.6 58 8.80 17.9 8.5 47.5 12.3 68.7 0.0
4 Mg(ClO3) 2 liquid - 8
l/ha (standard)
20-30 57.3 6.8 88.1 17.9 4.7 26.3 14.0 78.2 +22.7
5 30-40 57.7 5.7 90.8 18.0 6.4 35.6 14.3 79.4 +12.7
6 40-50 59.2 7.2 87.8 18.4 8.1 44.0 14.7 79.9 +11.2
7 Entodefol, 150
ml/ha, (standard)
20-30 56.4 10.2 81.9 17.6 5.0 28.4 13.0 73.9 +18.4
8 30-40 55.7 10.7 80.8 17.1 6.3 36.8 13.2 77.2 +10.5
9 40-50 65.0 14.0 78.5 17.6 8.3 47.2 14.2 80.7 +12.0
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 1 2 3 4 5 6 7 8 9 10 11 12
leaf fall,%
opening of
cotton bolls,%
first harvest
yield,s/ha
yield increase,
s/ha
Effect of composite defoliant on leaf, %opening of cotton bolls, first harvest yield and yield increase (data
for 2022, Bukhara-10)
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10 Mg(ClO3) 2 liquid - 4 l +
Phytovac 75 ml +
Urea 6.5 kg + Humin
1.5 kg/ha
20-30 64.9 12.9 80.1 18.9 5.0 26.5 16.1 85.2 +29.7
11 30-40 64.7 14.5 77.6 20.5 7.3 35.6 18.9 92.2 +25.5
12 40-50 67.7 10.0 84.7 20.0 9.2 46.0 18.8 94.0 +25.3
Early ripening cotton variety Bukhara-10 (2023)
1
Control, 00
20-30 60.9 56 8.0 18.5 4.7 25.4 11.5 62.2 0.0
2 30-40 64.9 62.0 4.5 19.3 7.3 37.8 12.8 66.3 0.0
3 40-50 68.2 65.0 2.9 19.9 8.7 43.7 14.7 73.9 0.0
4 Mg(ClO3)2liquid - 8 l/ha
(standard)
20-30 64.6 12.0 81.4 19.0 5.7 30.0 15.0 78.9 +16.7
5 30-40 71.5 15.0 85.4 20.5 7.5 36.6 16.5 80.5 +14.2
6 40-50 60.8 12.0 83.7 18.3 8.6 47.0 15.3 83.6 +9.7
7 Entodefol, 150
ml/ha, (standard)
20-30 63.0 11.0 82.5 18.7 4.9 26.2 14.0 74.9 +12.7
8 30-40 60.7 8.0 89.2 19.0 7.5 39.5 15.7 82.6 +16.3
9 40-50 60.1 7.0 85.4 20.3 9.1 44.8 17.1 84.2 +10.3
10 Mg(ClO3)2liquid - 4 l +
Phytovac 75 ml +
Urea 6.5 kg + Humin
1.5 kg/ha
20-30 61.1 12.0 81.0 20.4 6.0 30.0 19.0 93.1 +30.9
11 30-40 70.6 15.0 84.8 22.2 8.2 36.9 21.2 95.5 +29.2
12 40-50 68.3 13.3 80.5 20.9 9.8 46.9 20.2 96.7 +22.8
The dynamics of cotton boll opening in the variants of using tank mixtures of "Fitovak" 75 ml /
ha + Urea (6.5 kg / ha) + Humic substances (1.5 kg / ha) and half the rate of Mg (ClO3)2liquid in
the amount of 4 l / ha, was identical to the variants of their use at the full rate of consumption
(Mg (ClO3)2liquid - 8 l / ha). Ultimately, after three weeks after defoliation, on average 55.5-
68.7% (Bukh-8); 62-73.9% (Bukh-10) of opened bolls was counted on the control plants.
Whereas in the variants of using half doses of 4 l / ha Mg (ClO3)2liquid and tank mixture "Fitovak"
75 ml / ha, Urea (6.5 kg / ha), Humic substances (1.5 kg / ha) cotton bolls opened by 29.7-
25.5% (Bukhara-8); 30.9-29.2% more than the control. The highest percentage of cotton bolls
opening and the rate of boll ripening were the most effective (2022-2023) in variants 10-11-
12, in both varieties. It amounted to proportionally: 88.7-89.7-92.5%; + 28.6-29.7-24.7%
(Bukhara-8, 2022); 87-94.2-94.4%; + 20.7-28.9-22.7% (Bukhara-10, 2022); 85.2-92.2-94.0%;
+29.7-25.5-25.3% (Bukhara-8, 2023); 93.1-95.5-96.7%; +30.9-29.2-22.8% (Bukhara-10,
2023). Positive results compared to the control of the boll opening rate were observed in the
research years in 10 variants, respectively, for each cotton variety: +29.7% (Bukh-8); +30.9%
(Bukh-10) were higher.
Although in the 10th variant the percentage of the boll ripening rate was the highest, it should
be taken into account that, in the early time of defoliation, when the bolls opened by 20-30%,
at this time most of the fruit elements were still immature, including the seeds and cotton fibers.
Therefore, the gross yield was lower compared to variants 11-12. Table 3 shows the data on
the effect of the composite defoliant at different boll opening times on the yield indicators in
both cotton varieties for 2022-2023.
The yield indicators were determined after defoliation after 21 days, from each harvest and
each repetition of the variant, 100 cotton bolls were collected and the weight of one boll, the
weight of 1000 seeds, the yield, length and micronaire of the fiber were determined.
Analyzing Table 3, among the tested variants, over the years of research, the most positive
results were obtained in variants 10-11-12, which in terms of the share of the first harvest, the
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Latibovna, I. M., Nimatovich, R. B., Bobomurotovich, A. D., Isaevich, M. S., & Chorievich, G. I. (2024). Influence of "Composite Defoliant" on Cotton
Crop Yield and the Environment. Discoveries in Agriculture and Food Sciences, 12(6). 89-104.
URL: http://dx.doi.org/10.14738/dafs.126.17851
weight of one boll and the increase in yield were significantly greater than the control and
reference variants.
When recording the weight of one cotton bolls, it was noted that before the first cotton harvest
in the 10-11-12 variants, an increase in the weight of one boll on one plant was observed.
Accordingly, it amounted to an average (Bukh-8 and Bukh-10, 2023) in the range from 8.5 g to
8.7 g. While in the control and reference variants there were only 8.0-8.2-7.5 g (control); 7-8 g
(reference, magnesium chlorate); 7.7-7.8 g; 7.0-7.2 g (reference, Entodefol), (2022-2023).
Among the studied variants, the best quality was in variants - 11-12.
Table 3: Effect of the composite defoliant at different boll opening times on the yield
indicators in both cotton varieties (2022-2023)
Options Number of
mature cotton
bolls, pcs/plant
Weight of one
boll, g
First harvest,
c/ha
Total harvest,
c/ha
Yield,
difference to
control, c/ha
2022y 2023y 2022y 2023y 2022y 2023y 2022y 2023y 2022y 2023y
Mid-season cotton variety Bukhara-8 (2023)
1 14,3 17,3 7,9 8,0 36,6 36,8 45,0 42,2 0,0 0,0
2 15,0 18,0 8,0 8,1 37,2 38,2 45,6 46,1 0,0 0,0
3 14,9 17,9 8,0 8,2 37,4 40,5 45,6 47,3 0,0 0,0
4 14,9 17,9 7,6 7,0 40,4 40,2 45,5 44,3 +0,5 +2,1
5 15,0 18,0 7,7 7,5 42,0 43,5 46,3 47,6 +0,7 +1,5
6 15,4 18,4 7,7 8,0 42,8 45,4 46,9 50,5 +1,3 +3,2
7 14,6 17,6 7,7 7,2 42,9 42,7 46,3 46,7 +1,3 +4,5
8 14,1 17,1 7,8 7,2 42,2 43,3 46,5 48,9 +0,9 +2,8
9 14,6 17,6 7,8 7,3 42,5 43,9 46,9 50,2 +1,3 +2,9
10 15,9 18,9 8,4 8,5 44,3 46,8 49,9 52,3 +4,9 +10,1
11 16,5 20,5 8,5 8,5 45,2 50,5 52,5 56,1 +6,9 +10,0
12 16,0 20,0 8,5 8,6 46,5 51,2 50,6 57,3 +5,0 +10,0
Early ripening cotton variety Bukhara-10 (2023)
1 20,5 18,5 7,8 7,5 39,6 40,5 44,6 44,7 0,0 0,0
2 21,3 19,3 7,9 7,5 39,1 41,2 44,4 44,3 0,0 0,0
3 21,9 19,9 7,9 7,5 36,0 41,1 42,1 43,5 0,0 0,0
4 21,0 19,0 7,5 7,5 41,1 42,0 45,8 46,0 +1,2 +1,3
5 22,5 20,5 7,6 7,8 44,9 42,5 46,5 47,0 +2,1 +2,7
6 19,3 18,3 7,6 7,4 44,0 43,1 46,5 47,1 +4,4 +3,6
7 20,7 18,7 7,6 7,0 43,1 44,3 45,0 45,5 +0,4 +0,8
8 21,0 19,0 7,6 7,2 41,3 42,5 45,8 46,2 +1,4 +1,9
9 22,3 20,3 7,7 8,0 42,3 43,1 46,4 47,3 +4,3 +3,8
10 22,4 20,4 8,3 8,65 45,7 46,8 50,2 51,0 +5,6 +6,3
11 24,2 22,2 8,4 8,65 55,6 54,6 57,0 55,0 +12,6 +10,7
12 19,9 20,9 8,4 8,7 53,3 52,8 55,3 54,8 +13,2 +11,3
(Least Significant Difference) LSD05 = 1,5c/ha; LSD05 = 4, 9%; 2022.) (LSD05 = 1.3c/ha; LSD05 =4,89%; 2023
As a result of accelerated opening of cotton bolls, in variants 10-11-12 of application of half
rates of defoliant Mg (ClO3)2liquid 4 l / ha and a combined mixture (Fitovak 75 ml + Carbamide
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Discoveries in Agriculture and Food Sciences (DAFS) Vol 12, Issue 6, December- 2024
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6.5 kg + humin 1.5 kg / ha) the yield of raw cotton of the first harvest increased in both varieties,
which varied within 45.7-46.8 c / ha; (10 var.); 55.6-54.6 c/ha (11 variants); 53.3 - 52.8 c/ha
(12 variants). That compared to the control, the yield increase was respectively: +6.1-6.3 c/ha;
+16.5-13.4 c/ha; + 17.3-11.7 c/ha. (Bukhara-10, 2022-2023). And the mid-season variety
Bukhara-8 also showed similar data: 44.3-46.8 c/ha (10 variants); 45.2-50.5 c/ha (11 variants);
45.1-46.58 c/ha (12 variants), that the yield increase between the control by years and variants,
respectively, was: +7.7-10.0 c/ha; +8.0- 12.3 c/ha; +9.1-10.7 c/ha (Bukhara-8, 2022-2023);
One of the main indicators of the effectiveness of composite plant defoliants, along with their
impact on crop yield, can also include their impact on the technological properties of fiber and
oil content.
Research by F. Teshaev [21], A. Kadyrov [9], Cothren, J T et al. [22], Rajni S, et al., [23] Gus Shaw
et al. [24], Sun Y., Veerabomma S. et al. [25], scientists has proven that plant growth regulators
do not reduce the quality indicators of the crop.
Our studies on the impact of composite defoliants on the technological qualities of fiber and
seed oil content have shown that the tested (composite defoliant) 11-12- variants (Mg (ClO3) 2
liquid 4 l / ha + Fitovac 75 ml + Urea 6.5 kg + humin 1.5 kg / ha) had a positive impact on these
indicators. The results of the analyses are presented in Table 4, from which it is evident that
(Fitovak + Urea + Humin) of plants not only improve the quality of the fiber, oil content, but
also slightly increase the weight of one boll and cotton seeds.
Analyzing the data of Table 4, positive data on the weight of 100 capsules and 1000 seeds were
obtained when spraying was performed at the time of capsule opening by 30-40 and 40-50%.
In the experimental variants of both varieties, these indicators varied within the range: from
700g to 870g; from 132g to 144g (Bukhara-10); 700-860g; 132-140g (Bukhara-8).
Among the tested variants, the highest indicators were in variants 11-12 in both varieties,
which were 865-870g; 850-860g; 140-144g; 140-140g. (Table4.)
Table 4: Effects of composite defoliant on technological qualities of fiber and oil content
of seeds (2023)
Options Weight of
100 boll, g
Weight of
1000 pcs.
seeds, g
Fiber
yield, %
Fiber
length, mm
Microneedle
indicators
Oil content
of seeds, %
Early ripening cotton variety Bukhara-10
1 750 136 38,5 35,6 4,5 20,8
2 750 137 38,5 35,5 4,3 20,9
3 750 138 38,7 35,6 4,2 21,1
4 750 134 37,7 35,3 4,5 20,7
5 780 136 38,1 35,6 4,2 21,1
6 740 138 37,8 35,5 4,2 21,2
7 700 132 37,1 35,8 4,5 20,8
8 720 138 36,7 35,5 4,1 21,0
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Latibovna, I. M., Nimatovich, R. B., Bobomurotovich, A. D., Isaevich, M. S., & Chorievich, G. I. (2024). Influence of "Composite Defoliant" on Cotton
Crop Yield and the Environment. Discoveries in Agriculture and Food Sciences, 12(6). 89-104.
URL: http://dx.doi.org/10.14738/dafs.126.17851
9 800 138 37,8 35,5 4,1 21,2
10 865 140 38,2 35,9 4,3 21,8
11 865 140 38,7 36,0 4,1 22,3
12 870 144 38,5 36,0 4,1 22,4
Mid-season cotton variety Bukhara-8
1 800 135 37,5 34,8 4,5 20,5
2 810 136 37,7 34,6 4,3 20,6
3 820 138 37,8 34,7 4,3 20,8
4 700 132 38,3 34,6 4,5 20,4
5 750 135 37,7 34,4 4,4 20,8
6 800 136 38,1 34,9 4,4 20,9
7 720 133 37,9 34,8 4,5 20,5
8 720 133 38,2 34,7 4,4 20,7
9 730 134 38,4 35,0 4,2 20,9
10 850 139 38,1 34,9 4,2 21,5
11 850 140 38,3 35,0 4,1 22,0
12 860 140 38,4 35,0 4,1 22,1
According to the yield indicators and fiber length, Mic., and seed oil content, similar data were
also obtained in variants 11-12, and, respectively, amounted to: 38.3-38.4%; 35-35 mm; 4.1-
4.1; 22-22.1% (Bukhara-8); 38.7-38.5%; 36-36 mm; 4.1-4.1; 22.3-22.4% (Bukhara-10).
If we pay attention to the above data, why exactly with the combined mixture (Fitovak 75 ml +
Urea 6.5 kg + humin 1.5 kg / ha) with Mg (ClO3)2 liquid 4 l / ha increases the weight of one cotton
bolls, 1000 pcs of seeds improves the technological properties of raw cotton, and in two
reference variants, on the contrary, decreases?
These phenomena are explained by the following physiological mechanism of action: each
vegetative and generative organ of the plant growth point has meristematic tissues.
Phytohormones are located in them. When combined tank mixtures were used in the process
of defoliation at different times of opening of cotton bolls, under the action of these composite
mixtures (Fitovak) they are activated by phytohormones, with the help of enzymes. In the
composition of humic substances, which contain proteins, in urea, nitrogen compounds and
other substances, all these compositions in the process of biochemical reactions with the help
of enzymes break down proteins into amino and nucleic acids and others, i.e. nutrients are
transformed into an easily digestible form of plants.
As a result, the digestible form of nutrients has a positive effect on the weight of one boll and
the quality of fiber and seeds. And also the use of a composite defoliant for 3 weeks, in the
process of falling of cotton leaves; hormones control auxin - ethylene balances. The defoliant
surrounds the auxin hormone and at the same time the growth of plants stops, and the
development process, on the contrary (ethylene) is activated. The aging process is underway.
The nutrients (which are present in the composite mixture Fitovak + urea and humins) are
redistributed on the conducting layer of cotton. Due to fallen leaves, all nutrients penetrate into
the cotton bolls more than in the control variants, the amount of ethylene increases, and auxin
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Discoveries in Agriculture and Food Sciences (DAFS) Vol 12, Issue 6, December- 2024
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decreases, in connection with this, the rate of boll ripening accelerates, the weight of one boll
increases due to urea and humins, as well as other yield indicators, technological properties
improve.
CONCLUSIONS
Based on the studied data, it can be concluded that when using as a defoliant, composite tank
mixtures of Mg (ClO3) 2 liquid 4 / ha, immune stimulant "Fitovak" 75 ml / ha, urea 6.5 kg / ha and
humin salt 1.5 kg / ha, turned out to be the most effective preparations.
The recommended rate of combined mixtures reduces the consumption rates of Mg (ClO3)2 liquid
and other pesticides by 50% per hectare. At the same time, the "hard-acting" defoliant
manifests itself as a "soft-acting".
Due to the use of a composite defoliant, a separating layer is formed between the shoots and
leaves of cotton. Nutrients (Fitovak + urea + humin) penetrate through the conductive systems
not into the leaves, but into the cotton bolls.
The amount of ethylene in the organs increases. Auxin decreases, due to this, the rate of boll
ripening accelerates, the weight of one boll increases, the rate of boll ripening accelerates, as
well as other yield indicators, the technological properties of the fiber improve.
The highest yield of raw cotton of the first harvest of both varieties, respectively, were: 45.2-
46.5 c / ha (11-12 var. Bukh-8, 2022); 50.5-51.2 c / ha (11-12 var. Bukh-8, 2023); 55.6-53.3 c /
ha (11-12 var. Bukhara-10, 2022); 57.0-55.3 c / ha (11-12 var. Bukhara-10, 2023); yield
increase (+16.5-13.4 c/ha; + 17.3-11.7 c/ha), (Bukhara-10); +8.0- 12.3 c/ha; +9.1-10.7 c/ha
(Bukhara-8) was higher than the control.
The rates of boll opening were respectively: 57.6-57.3-46.6% (Bukhara-10) 46.6%; 61.2-51.2-
45.5% (Bukhara-8), higher than the control (data - 2023). The percentage of boll opening in
varieties in variants 10-11-12, respectively: 87-94.2-94.4%; 88.7-89.7-92.5%.
Foliage coverage of both cotton varieties, respectively: 81.6-84.8-83.65; 85.3-86.4-84.7% were
closer to the standard, and was achieved with half the consumption rate of Mg (ClO3) 2 liquid (4 l
/ ha), in a tank mixture with "Fitovak" (75 ml / ha), urea (6.5 kg / ha) and humic acid derivatives
(1.5 kg / ha). Also, the technological properties of fiber and seeds are improved when using a
composite defoliant at boll openings of 30-40 and 40-50%. The use of a composite defoliant at
30-40% boll opening allows cotton growers to quickly harvest raw cotton from the field
without damaging.
АСKNОWLЕDGMЕNTS
We sincerely express our gratitude to the head of the experimental farm of the Bukhara
Scientific Experimental Station, located in the city of Bukhara, for allowing us to conduct
laboratory and field research. We also sincerely thank the members of the editorial boards for
publishing in the journals "African Journal of Biological Sciences".
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Latibovna, I. M., Nimatovich, R. B., Bobomurotovich, A. D., Isaevich, M. S., & Chorievich, G. I. (2024). Influence of "Composite Defoliant" on Cotton
Crop Yield and the Environment. Discoveries in Agriculture and Food Sciences, 12(6). 89-104.
URL: http://dx.doi.org/10.14738/dafs.126.17851
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