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SPREAD AND DEVELOPMENT OF LATE BLIGHT DISEASE IN
POTATOES
U.K.Khamirayev
Associate Professor, Tashkent State Agrarian University
Toshmetova Dilfuza Valivoevna
PhD Candidate, Tashkent Branch of the Samarkand State University of
Veterinary Medicine and Animal Husbandry Biotechnology
https://doi.org/10.5281/zenodo.15636655
Annotation:
Potatoes are considered one of the staple food products in the
daily life of the global population, as they are a valuable source of essential
carbohydrates, vitamins, proteins, and other nutrients. Potatoes are one of the
most important agricultural crops and are rightfully referred to as the “second
bread.” China, India, Russia, the USA, Germany, Bangladesh, Poland, France, and
the Netherlands are among the leading producers of potatoes. Uzbekistan ranks
23rd on this list. To achieve high yields and ensure domestic supply of locally
grown potatoes, the implementation of several effective measures is necessary.
This article presents the monitoring results of studies conducted on the spread
and development of late blight disease in potato fields in the Samarkand region
during 2022–2024.
Keywords:
Late blight, vitamin, monitoring, mineral, disease, fungus,
Chromista, phylum, Oomycota, Perenomycetidae, Pythiales, Pytiaceae,
Phytophthora
.
Introduction:
Scientific research is being conducted at the “International
Potato Center (CIP) in Peru,” the Azerbaijan Vegetable Research Institute, VNIIF,
and KazNIIKO centers on the evolution, bioecology, epidemiology, and genetics
of fungal pathogens affecting potatoes [10]. Evidence of this can be seen in the
notable reduction of crop losses caused by fungal diseases of potatoes. In
protecting potatoes from diseases, it is crucial to understand the dynamics of
disease spread and development in order to apply chemical control measures
properly. This is especially important today, as the indiscriminate use of
chemical agents can have negative impacts on the environment, humans,
livestock, and domestic animals, and must be strictly regulated [5]. The
protection of potatoes from diseases is closely linked to their nutritional
importance, as potato tubers contain essential substances for the human div
such as vitamins, minerals, and organic acids. According to V.F. Lishenko,
potatoes contain sufficient amounts of minerals like K, Ca, P, Mg, Na, Mn, Zr, F,
and I, as well as vitamins such as thiamine (B1), riboflavin (B2), niacin (B3),
pyridoxine (B6), and folacin (B9), making them a vital nutritional source for
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human health. In addition, potatoes are classified as a dietary food product due
to their low fat content, which is significant since high levels of fats are generally
considered harmful to the div. According to British dietitians, maintaining a
proper balance of different food groups in the human diet is of great importance.
A healthy and balanced diet should ideally consist of the following proportions:
potatoes, bread, and other cereal products – at least 33%; vegetables and fruits –
33%; dairy products – 15%; meat, fish, and other protein alternatives – 12%;
and products containing fats and sugars – 7% [4], [6]. Given the importance of
potatoes in human nutrition, fungal diseases are recognized as a major factor in
yield reduction. Most fungi persist in plant residues and soil, and due to nutrient
deficiencies, their potential to spread increases significantly [1], [6], [7].
Symptoms of late blight in potatoes first appear during the budding and
flowering stages, initially manifesting as irregularly shaped spots on the upper
parts of the plant and along the leaf edges. After a short period, water-soaked
lesions develop on the leaves, which then gradually turn dark brown or deep
brown with a narrow yellow border. In humid weather conditions, the
undersides of the leaves are often covered with a soft, thin, whitish-gray mold
layer [3], [7].
At present, plant diseases play a significant role in the sharp decline of
potato yields. These diseases also cause substantial damage during the storage
period of crops. Among the pathogenic microorganisms,
Phytophthora infestans
stands out for its negative impact on productivity during both the vegetation and
storage phases. The disease caused by
Phytophthora infestans
is known as
late
blight
. The species
Phytophthora infestans
is currently taxonomically classified
as follows:
Kingdom
– Chromista,
Phylum
– Oomycota,
Class
–
Perenomycetidae,
Order
– Pythiales,
Family
– Pytiaceae,
Genus
–
Phytophthora
[8].
Study Area and Research Methods
During the years 2022–2024, a study was conducted to monitor the spread,
development, and disease index of late blight (
Phytophthora infestans
) in potato
fields across various districts of the Samarkand region. Monitoring was carried
out in the following locations:
Jomboy district
: “Bozorov Zohid Zamini,” “Nush
Agro Grand,” “Farangiz Nurli Zamin,” “Kamola,” “Ravshan,” “O‘razali Fayz
Dalasi”,
Narpay district
: “Ro‘zimurod Dehqon,” “G‘alaba Qahramon Ota,”
“Ravshanbek Dalalari,” “Amirxon Asl Agro,” “Samandar Rahmon,” “Azimjon
Tojiev,” “Amirxon Mirbozor Dalalari,” “Narpay Yaxshi Niyat”,
Payariq district
:
“Saxovatli Pangat Zamini,” “Musabek Chorva Kompleksi”,
Pastdargom district
:
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“Shomurod Bobo”,
Samarkand district
: “Qurbonboy Mitinovich,” “Hakimov
Abduhalim”,
Oqdaryo district
: “Ezozbek Asl Dalalari,” “Temurxon Mullaxo‘ja”,
Toyloq district
: The Research Institute of Vegetable, Melon, and Potato Crops,
Samarkand Experimental Research Station. As a result of this monitoring, data
were collected on the spread of late blight in potato fields, including the disease
index and its rate of development.
Research Results
In order to assess the spread and development of late blight disease
(
Phytophthora infestans
), 50 potato plants were selected from five different
diagonal points in each field (10 plants per point). Symptoms of late blight were
recorded on infected leaves and stems, and disease development was evaluated
using a 5-point scale.
2022 Results.
In 2022, among all monitored locations in Samarkand
region, the
highest incidence and severity
of late blight were observed in the
‘Nush Agro Grant’ farm
in
Jomboy district
, particularly in the
‘Umid’
variety.
Out of 50 observed plants, 15 (30.0%) showed symptoms of the disease. Of
those: 2 plants were infected up to score 1,4 plants up to score 2,5 plants up to
score 3,4 plants up to score 4. Disease development reached
20.5%
, and the
disease index was calculated at
6.2%
(Table 4.15). Other varieties in the same
district showed lower disease incidence:
‘Rozara’
– 14.0% incidence, 4.0%
development,
‘Sante’
– 10.0% incidence, 2.5% development,
‘Gala’
– 18.0%
incidence, 5.0% development.The second-highest rate of late blight was
recorded in
Pastdargom district
, at the
‘Shomurod Bobo’
farm with the
‘Aqrab’
variety. 14 of 50 plants (28.0%) were affected: 2 plants scored up to 1,3
up to score 2,5 up to score 3,4 up to score 4.The disease index here was
5.5%
.
The
lowest incidence and mildest development
were observed at the
‘Ro‘zimurod Dehqon’
farm in
Narpay district
, with the
‘Picasso’
variety: only
4 plants (8.0%) were infected, and disease development was 3.0%. In the same
district, the
‘Romano’
variety at
‘G‘alaba Qahramon Ota’
farm showed: 20.0%
incidence, 7.0% development, 1.4% disease index. At
‘Ravshanbek Dalalari’
and
‘Amirxon Asl Agro’
farms, late blight incidence ranged between 12.0–
14.0%, and development was 4.0–4.5%. In
Payariq district
, the
‘Evolution’
variety at
‘Saxovatli Pangat Zamini’
farm showed 18.0% infection (9 out of 50
plants).
At
‘Musabek Chorva Kompleksi’
, the
‘Gala’
variety had 22.0% incidence.
Disease development in both cases was
6.5%
. In
Samarkand district
, at the
‘Qurbonboy Mitinovich’
and
‘Hakimov Abduhalim’
farms growing the
‘Sante’
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variety, late blight incidence ranged between 16.0–18.0%, development
between 5.0–5.5%, and disease index ranged from 0.1–0.8%. Infection levels did
not exceed score 2.In
Oqdaryo district
,
‘Fusarium’
incidence ranged from
14.0–18.0%, with 5.0–7.5% development in
‘Ezozbek Asl Dalalari’
and
‘Temurxon Mullaxo‘ja’
farms. In the
‘Picasso’
variety, 9 out of 50 plants were
affected (mostly up to score 1 or 2). In the
‘Romano’
variety, 7 plants were
infected, 4 up to score 1 and 3 up to score 2 (Table 1).
2023 Results.
In 2023, widespread and severe late blight infections were
again observed in the
‘Umid’
variety, especially at
‘Nush Agro Grant’
farm in
Jomboy
and
‘Hakimov Abduhalim’
farm in
Samarkand district
:
‘Nush Agro
Grant’
: 15 out of 50 plants (30.0%) infected, 11.0% disease development,
3.3%
disease index
.
‘Hakimov Abduhalim’
: 16 out of 50 plants (32.0%) infected, 11.5%
development,
3.7% disease index
(Table 2). In
Narpay district
, the
‘Aqrab’
variety again showed significant infection: 13 out of 50 plants (26.0%) infected. 2
plants up to score 1, 3 up to score 2, 4 up to score 3, and 4 up to score 4.
Disease
index: 4.7%.
At
‘Ro‘zimurod Dehqon’
, the
‘Picasso’
variety had: 12.0% incidence,
4.0% development,0.5% disease index (max score 2). The
‘Romano’
variety at
‘G‘alaba Qahramon Ota’
farm showed: 18.0% incidence,5.5% development. At
‘Ravshanbek Dalalari’
, the
‘Evolution’
variety showed: 8.0% incidence,2.0%
development, 0.2% disease index. In
Payariq district
, at both
‘Saxovatli Pangat
Zamini’
(var. ‘Evolution’) and
‘Musabek Chorva Kompleksi’
(var. ‘Gala’),
moderate disease incidence was observed (12.0–20.0%) with development
between 3.5–5.5%. At
‘Qurbonboy Mitinovich’
in
Samarkand district
, the
‘Sante’
variety showed no symptoms of late blight. At
‘Shomurod Bobo’
in
Pastdargom
, only 2 of 50 plants (4.0%) of the
‘Sante’
variety were affected, each
with up to score 1 or 2. In
Oqdaryo
, at
‘Ezozbek Asl Dalalari’
, the
‘Picasso’
variety had: 16.0% incidence, 4.0% development, 0.6% disease index. At
‘Temurxon Mo‘llaxo‘ja’
, the
‘Romano’
variety showed: 8.0% incidence, 2.0%
development.
In 2024, the
highest incidence
of
Phytophthora infestans
(late blight) on
potato fields (32.0%) was recorded in the
'Umid' variety
cultivated at the farms
of
‘Qurbonboy Mitinovich’
in
Samarkand district
and
‘Temurxon
Mo‘llaxo‘ja’
in
Oqdaryo district
. In both farms, 16 out of 50 observed plants
(32.0%) showed symptoms of late blight (see Table 3). The
most severe
disease development
was observed in the
'Aqrab' variety
at
‘Saxovatli
Pangat Zamini’
farm in
Payariq district
–
20.0%
, and the
'Evolution' variety
at
‘Shomurod Bobo’
farm in
Pastdarg‘om district
–
15.5%
. In
‘Saxovatli
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Pangat Zamini’
, among the 15 infected plants: 3 were affected up to score 1, 3
up to score 2, 5 up to score 3, 4 up to score 4. In
‘Shomurod Bobo’
, out of 15
infected plants: 6 scored up to 1, 4 up to 2, 3 up to 3, 2 up to 4. In
‘Qurbonboy
Mitinovich’
, the
'Umid'
variety had:
32.0% incidence
,
12.0% development
.
However, in the same district, the
‘Hakimov Abduhalim’
farm growing the
‘Sante’
variety showed
no signs of late blight
. In
Jomboy district
, late blight
incidence ranged between
6.0–22.0%
, and disease development ranged from
1.5–9.0%
. Specifically: ‘Gala’ – 12.0% incidence, 3.5% development, ‘Sante’ –
6.0% and 18.0% incidence, 1.5% and 5.5% development, ‘Aqrab’ – 18.0%
incidence, 6.5% development, ‘Evolution’ – 22.0% incidence, 9.0% development.
In
Narpay district
, late blight incidence ranged from
4.0–20.0%
, and disease
development between
1.0–6.5%
: ‘Picasso’ – 16.0% incidence, 6.0%
development, ‘Romano’ – 18.0% incidence, 6.5% development, ‘Sante’ – 20.0%
incidence, 6.5% development, ‘Rozara’ – 4.0% incidence, 1.0% development. In
Payariq
, at
‘Saxovatli Pangat Zamini’
, the
‘Aqrab’
variety showed: 30.0% of
plants (15 out of 50) infected, scoring: 3 up to 1, 3 up to 2, 5 up to 3, 4 up to 4,
disease index: 6.0%
. At
‘Musabek Chorva Kompleksi’
, the
‘Gala’
variety
showed:
24.0% incidence
,
8.0% development
, and
disease index: 1.9%
. In
Oqdaryo district
, the
‘Picasso’
variety at
‘Ezozbek Asl Dalalari’
showed high
Fusarium
infection:
28.0% incidence
,
14.5% development
. Among the 14
infected plants 6 scored up to 1,3 up to 2, 3 up to 3, 2 up to 4. The
disease index
was 4.1%
. In the same district, the
‘Umid’
variety showed:
32.0% incidence
,
14.5% development
,
disease index: 4.6%
.
1-table
The spread and development of late blight disease in potato fields of some
districts of Samarkand region in 2022
№
Districts
Farm name
Variety
of
potato
Total
number
of
studied
plants,
units
Number of plants by
degree of infection
(individual stems,
stalks, and leaves),
units
Kt,
%
Kr,
%
Ki,
%
Infection rating
0
1 2 3
4
1
Jomboy
“Bozorov Zoxid zamini” f/x
Rozara
50
43
6 1 0
0
14,0
4,0
0,6
“Nush agro grant” f/x
Umid
50
35
2 4 5
4
30,0 20,5
6,2
“Farangiz nurli zamin” f/x
Aqrab
50
40
5 5 0
0
20,0
7,5
1,5
“Kamola” f/x
Sante
50
45
5 0 0
0
10,0
2,5
0,3
“Ravshan” f/x
Gala
50
41
8 1 0
0
18,0
5,0
0,9
2
Narpay
“Ro‘zimurod dexqon” f/x
Pikasso
50
46
2 2 0
0
8,0
3,0
0,2
“G‘alaba Qaxramon ota” f/x
Ramano
50
40
7 2 1
0
20,0
7,0
1,4
“Ravshanbek dalalari” f/x
Evolyush
n
50
43
6 1 0
0
14,0
4,0
0,6
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“Amirxon asl agro” f/x
Rozara
50
44
3 3 0
0
12,0
4,5
0,5
3
Payariq
“Saxovatli pangat zamini”
f/x
Evolyush
n
50
41
6 2 1
0
18,0
6,5
1,2
“Musabek chorva
kompleksi” f/x
Gala
50
39
9 2 0
0
22,0
6,5
1,4
Samarqand
“Qurbonboy Mitinovich” f/x Sante
50
41
7 2 0
0
18,0
5,5
1,0
“Hakimov Aduhalim” f/x
Sante
50
42
6 2 0
0
16,0
5,0
0,8
4
Pasdarg‘om
“Shomurod bobo” f/x
Aqrab
50
36
2 3 5
4
28,0 19,5
5,5
5
Oqdaryo
“Ezozbek Asl dalalari” f/x
Pikasso
50
41
5 2 2
0
18,0
7,5
1,4
“Temurxon Mo‘llaxo‘ja” f/x
Ramano
50
43
4 3 0
0
14,0
5,0
0,7
Note: Kt, % – disease incidence; Kr, % – disease severity; Ki, % – disease index.
2-table
The spread and development of late blight disease in potato fields of some
districts of Samarkand region in 2023
№
Districts
Farm name
Variety
of potato
Total
number
of
studied
plants,
units
Number of plants by
degree of infection
(individual stems,
stalks, and leaves),
units
Kt,
%
Kr,
%
Ki,
%
Infection rating
0
1
2
3
4
1
Jomboy
“Bozorov Zoxid zamini” f/x
Gala
50
42
6
2
0
0
16,0
5,0
0,8
“Nush agro grant” f/x
Umid
50
35 10
3
2
0
30,0 11,0
3,3
“Farangiz nurli zamin” f/x
Rozara
50
41
6
3
0
0
18,0
6,0
1,1
“Kamola” f/x
Sante
50
43
7
0
0
0
14,0
3,5
0,5
“Ravshan” f/x
Gala
50
44
5
1
0
0
12,0
3,5
0,4
2
Narpay
“Ro‘zimurod dexqon” f/x
Pikasso
50
44
4
2
0
0
12,0
4,0
0,5
“G‘alaba Qaxramon ota” f/x
Ramano
50
41
7
2
0
0
18,0
5,5
1,0
“Ravshanbek dalalari” f/x
Evolyush
n
50
46
4
0
0
0
8,0
2,0
0,2
“Amirxon asl agro” f/x
Aqrab
50
37
2
3
4
4
26,0 18,0
4,7
3
Payariq
“Saxovatli pangat zamini” f/x
Evolyush
n
50
44
5
1
0
0
12,0
3,5
0,4
“Musabek chorva kompleksi”
f/x
Gala
50
40
9
1
0
0
20,0
5,5
1,1
Samarqan
d
“Qurbonboy Mitinovich” f/x
Sante
50
50
0
0
0
0
0,0
0,0
0,0
“Hakimov Aduhalim” f/x
Umid
50
34 11
3
2
0
32,0 11,5
3,7
4
Pasdarg‘o
m
“Shomurod bobo” f/x
Sante
50
48
1
1
0
0
4,0
1,5
0,1
5
Oqdaryo
“Ezozbek Asl dalalari” f/x
Pikasso
50
42
8
0
0
0
16,0
4,0
0,6
“Temurxon Mo‘llaxo‘ja” f/x
Ramano
50
46
4
0
0
0
8,0
2,0
0,2
Note: Kt, % – disease incidence; Kr, % – disease severity; Ki, % –
disease index.
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3-table
Spread and Development of Late Blight Disease in Potato Fields in Certain
Districts of Samarkand Region in 2024.
№
Districts
Farm name
Variety
of potato
Total
number
of
studied
plants,
units
Number of plants by
degree of infection
(individual stems,
stalks, and leaves), units
Kt,
%
Kr,
%
Ki,
%
Infection rating
0
1
2
3
4
1
Jomboy
“Bozorov Zoxid zamini” f/x
Gala
50
44
5
1
0
0
12,0
3,5
0,4
“Nush agro grant” f/x
Sante
50
47
3
0
0
0
6,0
1,5
0,1
“Farangiz nurli zamin” f/x
Aqrab
50
41
5
4
0
0
18,0
6,5
1,2
“Kamola” f/x
Sante
50
41
7
2
0
0
18,0
5,5
1,0
“Ravshan” f/x
Evolyush
n
50
39
6
3
2
0
22,0
9,0
2,0
2
Narpay
“Ro‘zimurod dexqon” f/x
Pikasso
50
42
4
4
0
0
16,0
6,0
1,0
“G‘alaba Qaxramon ota” f/x
Ramano
50
41
6
2
1
0
18,0
6,5
1,2
“Ravshanbek dalalari” f/x
Sante
50
40
7
3
0
0
20,0
6,5
1,3
“Amirxon asl agro” f/x
Rozara
50
48
2
0
0
0
4,0
1,0
0,0
3
Payariq
“Saxovatli pangat zamini”
f/x
Aqrab
50
35
3
3
5
4
30,0 20,0
6,0
“Musabek chorva
kompleksi” f/x
Gala
50
38
9
2
1
0
24,0
8,0
1,9
Samarqan
d
“Qurbonboy Mitinovich” f/x Umid
50
34
10
4
2
0
32,0 12,0
3,8
“Hakimov Aduhalim” f/x
Sante
50
50
0
0
0
0
0,0
0,0
0,0
4
Pasdarg‘o
m
“Shomurod bobo” f/x
Evolyush
n
50
35
6
4
3
2
30,0 15,5
4,7
5
Oqdaryo
“Ezozbek Asl dalalari” f/x
Pikasso
50
36
6
3
3
2
28,0 14,5
4,1
“Temurxon Mo‘llaxo‘ja” f/x
Umid
50
34
9
3
2
2
32,0 14,5
4,6
Note: Kt, % – disease incidence; Kr, % – disease severity; Ki, % – disease index.
Conclusion.
In 2022, the incidence of late blight (
Phytophthora infestans
) in
potato fields across Samarkand region ranged from
8.0% to 30.0%
, with
disease development levels ranging from
3.0% to 20.5%
. The
highest
incidence (30.0%)
and
most severe development (20.5%)
were observed in
the
‘Umid’ variety
cultivated at the
‘Nush Agro Grant’
farm in
Jomboy district
.
The
lowest incidence (8.0%)
and
mildest development (3.0%)
were
recorded in the
‘Picasso’ variety
grown at the
‘Ro‘zimurod Dehqon’
farm in
Narpay district
. In 2023, late blight incidence across potato fields in Samarkand
region ranged from
0.0% to 32.0%
, and disease development from
0.0% to
18.0%
. The
highest incidence (32.0%)
was recorded in the
‘Umid’ variety
at
the
‘Hakimov Abduhalim’
farm in
Samarkand district
, while the
most severe
development (18.0%)
occurred in the
‘Aqrab’ variety
at the
‘Amirxon Asl
Agro’
farm in
Narpay district
. The
lowest incidence (0.0–4.0%)
and
mildest
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development (0.0–1.5%)
were observed in the
‘Sante’
variety. In 2024, the
incidence of late blight in Samarkand region ranged from
0.0% to 32.0%
, and
disease development ranged from
0.0% to 20.0%
. The
highest incidence
(32.0%)
was found in the
‘Umid’ variety
at the
‘Qurbonboy Mitinovich’
farm
in
Samarkand district
, while the
highest disease development (20.0%)
was
recorded in the
‘Aqrab’ variety
at the
‘Saxovatli Pangat Zamini’
farm in
Payariq district
. The
lowest incidence (0.0–4.0%)
and
mildest development
(0.0–1.0%)
were again observed in the
‘Sante’
and
‘Rozara’
varieties.
References:
1.
Finckh M.R., Schulte G. E., Bruns C. Challenges to Organik Potato Farming.
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2.
Xamirayev O‘.K., “O’zbekistonning markaziy mintaqalarida kartoshkanning
fitoftoroz kasalligi va unga qarshi kurash choralarini takimillashtirishv”.,
Monografiya // . Toshkent 2023 y. 110-b.
3.
Игнатов А.Н., Панычева Ю.С., Воронина М.В., Джалилов Ф.С.
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4.
Лищенко В.Ф., Анисимов Б.В., Колчин Н.Н. и др Состояние и
перспектива развития продовольственной системы России (на примере
картофельного комплекса) //.М.:Экономика, 2016 446 с.
5.
Ряховская Н.И., Гайнатулина В.В., Макарова М.А. Экологическая
безопасные приемы защиты картофеля от болезней // Вестик. Росс. с-х
науки. 2017. № 3. С.57-61.
6.
Хамираев У.Қ., Рисбаев А.К. Agrokimyo himoya va o’simliklar karantini
илмий-амалий журнал. – Тошкент: 2023-№3 – 37-39 б.
7.
Хамираев
У.Қ.,
Ўзбекистоннинг
марказий
минтақаларида
картошканинг фитофтороз касаллиги ва унга қарши кураш чораларини
такомиллаштири // дисс. Тошкент 2022 й.
8.
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9.
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