Note: Descriptions are shown in the official language in which they were submitted.
GROWTH PROMOTER AND APPLICATION THEREOF FOR PREVENTION
AND TREATMENT OF CLUBROOT ON CRUCIFEROUS CROPS
Field of the Invention
The present invention relates to a crop growth regulator, in particular to a
growth
promoter for restoring a root absorption function and application thereof for
prevention and treatment of club root disease of cruciferous crops.
Background of the Invention
The club root disease, commonly known as plant cancer, is a special parasitic
soil-borne disease caused by infection of plasmodiophora brassicae woron,
which
mainly infects cruciferous plants such as oilseed rape, wild cabbage, cabbage,
cauliflower, kohlrabi, leaf mustard, radish and turnip. This disease mainly
damages
root tissues of plants, and causes proliferation of parenchyma cells of roots
to form
tumors, which makes it difficult for plants to absorb nutrients, leading to
wilting, slow
growth and even death of plants; and when conditions are suitable, it can lead
to the
decline of yield and quality of cruciferous crops such as oilseed rape, or
even total
crop failure. According to incomplete statistics, the disease causes more than
10%
economic losses to cruciferous crops in the world, and more than 70% losses to
some
crops. In China, the club root disease has covered the main planting areas of
oilseed
rape and cruciferous vegetables. According to incomplete statistics, at
present, the
spread area of club root disease of oilseed rape in China is at least 600000
hectares,
and the yield of oilseed rape is reduced by more than 1500kg per hectare,
threatening
the development of oilseed rape and cruciferous vegetable industry in China.
The club root disease is a worldwide soil-borne disease, and pathogens thereof
exist in
soil in the form of doirnant spores. They can adapt to extremely bad
environment and
survive for up to 15 years in the absence of susceptible host plants, which
makes it
very difficult to prevent and treat the disease. Fields with club root disease
pathogens
are generally not suitable for planting cruciferous plants. In addition,
traditional
agricultural operations, such as early sowing of oilseed rape and long-term
planting of
Date recue/Date received 2023-04-05
cruciferous crops in the same field, would aggravate the club root disease in
the
diseased field. At present, due to the lack of effective broad-spectrum club
root
disease resistant varieties, only chemical bactericides can be used for
prevention and
treatment in production, such that the amount of used chemicals is large, the
costs of
chemicals and labor are high, furthermore, there is no prevention and
treatment effect
under the case that the treatment with chemicals is performed after symptoms
appear,
and even worse, potential risks of environmental pollution and human health
are
caused by a large amount of chemicals for soil treatment. Therefore, the
prominent
problem that it is difficult to prevent and treat the club root disease has
not only
seriously hit the enthusiasm of farmers to plant cruciferous crops, but also
posed a
great threat to the sustainable development of oilseed rape and cruciferous
vegetable
industry. It is urgent to explore new strategies for prevention and treatment
of club
root disease.
In the previous work, the inventor of the present application has created a
seed
coating agent which can be used to prevent and treat the club root disease.
The
prevention rate for the club root disease at the seedling stage of oilseed
rape can reach
more than 80%, the usage amount of pesticides is significantly reduced, the
environmental affinity of the chemical prevention and treatment technology is
improved, and the technical barrier that it is difficult to prevent the club
root disease is
overcome. However, since the seed coating agent is limited by the usage amount
and
efficacy duration, it is difficult to effectively prevent and control the club
root disease
in the later growth stage of oilseed rape, and to cure the diseased plants. If
it is
capable to provide a novel plant growth promoter, which is free of chemical
pesticide,
is environment-friendly, can rebuild or restore the nolinal nutrient and water
absorption function of the root system of the club root diseased plants,
restore the
normal growth of the diseased plants which are dying and guarantee the yield
of
oilseed rape and cruciferous crops, is stable in the treatment effect on the
club root
disease, does not easily cause environmental pollution, and has a field use
effect that
is not affected by geological conditions and soil environment, not only can
the normal
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Date Recue/Date Received 2020-05-15
absorption function of the roots of the diseased plants be rebuilt or
restored, the crop
growth be promoted, the yield be increased, the use of pesticides be
significantly
reduced, the stability of the farmland ecosystem be improved and the planting
cost of
cruciferous crops be reduced, but also the technical bottleneck that the club
root
diseased plants are difficult to survive can be overcome, the major practical
production problem that it is difficult to treat the club root disease can be
truly solved,
the enthusiasm of farmers can be greatly stimulated and the sustainable and
safe
production of cruciferous crops can be promoted.
Summary of the Invention
In order to overcome the disadvantages of the existing prevention and
treatment
technology and overcome the technical bottleneck that the club root diseased
plants
are difficult to survive, the present invention provides a growth promoter
which can
restore the absorption function of roots and can be used to prevent and treat
club root
disease of cruciferous crops.
The growth promoter comprises the following components in parts by weight: 0.3-
0.5
part of indolebutyric acid, 0.3-0.5 part of naphthylacetic acid, 15-20 parts
of humic
acid, 10-20 parts of boron (based on element B) and 30-50 parts of plant
nutrient. The
technical purpose of the present invention is realized through the synergistic
effect of
the growth regulator (indolebutyric acid and naphthylacetic acid), humic acid,
boron
and plant nutrient, which are compounded according to appropriate components
and
proportions.
In the present invention, indolebutyric acid and naphthylacetic acid are
agricultural
available compounds. Humic acid is, for example, sodium humate or potassium
humate. Boron is at least one of boric acid, borax and boron-magnesium
fertilizer. The
plant nutrient is a complexing agent of nitrogen, phosphorus and potassium,
and the
mass ratio is preferably N:P:K = 4:1:1.
Previous studies have showed that the infection process of the club root
disease can be
divided into two stages, i.e., the root hair infection stage and the cortex
infection stage.
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Date Recue/Date Received 2020-05-15
The root hair infection stage refers to the stage that doimant spores
germinate and
infect root hairs and epidermal cells of plants. The infection at this stage
will not
cause obvious symptoms to host plants, nor directly cause the yield or quality
decline
of the host plants. The cortex infection stage refers to the stage that the
primary
zoosporangia release secondary zoospores to infect cortex cells, which leads
to the
proliferation and hypertrophy of root tissue cells and the formation of
swollen roots.
At this stage, the pathogens proliferate in a large scale in the host plants,
and the root
swelling seriously affects the water and nutrient absorption function of the
plants till
the plants are wilted and died. For the club root disease, if prevention and
treatment
with chemicals are adopted after symptoms appear, only a part of pathogens
left in
soil can be killed, but it has no effect on the pathogens in the host plants,
and it cannot
restore the normal water and nutrient absorption function of the roots, so the
club root
diseased plants are difficult to survive.
Indolebutyric acid, as an endogenous growth regulator, can promote cell
division and
cell growth, induce the formation of adventitious roots, increase fruit
setting, prevent
fruit abscission, and change the ratio of female flowers to male flowers.
Indolebutyric
acid can enter plants through tender epidermis of leaves and branches and
seeds, and
is transported to an acting position together with the nutrient flow. At
present,
indolebutyric acid is mainly used for the rooting of cuttings, and can induce
the
formation of root primordium, promote cell differentiation and division,
facilitate the
formation of new roots and vascular systems, and promote the formation of
adventitious roots of cuttings. Indolebutyric acid is generally used for root
soaking in
transplantation of woody and herbaceous plants, and it can also be used for
seed
soaking and seed dressing.
Naphthylacetic acid (NAA), a broad-spectrum plant growth regulator, can
promote
cell division and expansion, induce the formation of adventitious roots,
increase fruit
setting, prevent fruit abscission, and change the ratio of female flowers to
male
flowers. Naphthylacetic acid can enter the plants through the tender epidermis
of
leaves and branches and seeds, and is transported to the whole plants together
with the
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nutrient flow. Previous studies have shown that the use of a certain amount of
NAA or
sodium naphthalene in the plant growth process can significantly promote the
plant
growth and increase the yield. The results of treatment to papaya seeds by
using
different concentrations of NAA have showed that NAA increases the overall
germination rate, germination potential and vigor index of the seeds, and can
promote
the photosynthesis of different plants.
Humic acid is a macromolecular organic substance widely existing in nature,
which is
widely used in agriculture, forestry, animal husbandry, chemical industry or
the like.
In agricultural production, humic acid is mainly used to produce fertilizers
(such as
ammonium humate and potassium humate). The application of humic acid in soil
can
significantly improve the physical and chemical properties of the soil and
enhance the
fertilizer efficiency. Some studies have shown that the application of humic
acid in
soil can increase the content of microorganisms in soil, improve the nutrient
utilization rate of crops, and significantly increase the biomass of sweet
potato, grape,
cabbage, tomato and other crops. Appropriate addition of humic acid can
improve the
root system activity of normally growing oilseed rape seedlings, significantly
promote
root system growth, and increase the activity of antioxidant enzymes in
oilseed rape
cells and the content of chlorophyll.
Boron is a microelement whose main function is to provide plant nutrients.
Conventional boron refers to boron chemical products mainly including borax,
boric
acid and boron-magnesium fertilizer, which are used as agricultural
microelement
fertilizers. Boron is one of the essential nutrients in plants. It is absorbed
and utilized
by plants in the form of boric acid molecule (H3B03), which is not easy to
move in
plants. Boron can promote the growth of the root system and play an important
role in
the synthesis and transport of photosynthesis products, i.e., carbohydrate.
The main
role thereof is to have a special role in the normal process of fertilization.
Oilseed rape
is very sensitive to boron, and lack of boron will lead to flowering but not
fruiting,
resulting in large-scale yield reduction. Studies have showed that boron
application
can significantly increase the number of pods per oilseed rape plant, the
number of
Date Recue/Date Received 2020-05-15
seeds per pod, the weight of a thousand seeds and the yield. However, improper
application of boron easily causes boron poisoning to crops. Some scholars
also have
found that applying a certain proportion of calcium and boron fertilizers can
control
the occurrence of the club root disease.
The plant nutrient is to supplement various elements for plant growth to
promote
healthy plant growth. The main components of the plant nutrient in the present
invention are nitrogen, phosphorus and potassium, which are the nutrient
elements
demanded by plants during growth and taken away during harvest in a large
scale.
However, the amount of nitrogen, phosphorus and potassium returned to the soil
in
the form of residues and roots is not great, so it is often necessary to
supplement these
nutrients by applying fertilizers. Oilseed rape is a kind of crop that needs
more
fertilizers and has strong fertilizer tolerance. Nitrogen, phosphorus and
potassium are
necessary elements for the growth of oilseed rape. Results have showed that if
only
one, two or three of nitrogen, phosphorus, potassium and boron fertilizers are
applied,
it is difficult to significantly increase the yield of rapeseeds, and the
reasonable
combination and application of nitrogen, phosphorus, potassium and boron can
significantly promote the growth and increase the yield of oilseed rape.
In the long-term study, the inventor has found that even if the affected root
system
infected with Plasmodiophora brassicae rots completely, it will not spread to
and
jeopardize the adjacent healthy root tissues, and only a few of the remaining
healthy
roots can continuously maintain the nutrient and water supply to the
aboveground
plants, and make the diseased plants be in a growing state. In combination
with the
theory of plant cell totipotency, it is speculated that the diseased plants
can be induced
to grow new root systems through external stimulation and the normal
physiological
function of the root system of the affected plants can be restored through
rebuilding.
Through continuous years of study, it has shown that the traditional way that
the root
growth basically depends on application in soil is surmounted, and creatively
through
foliar spraying method and the growth promoter formula of the present
invention, the
healthy growth of the diseased plants is completely restored and the
physiological
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function of the root systems of the diseased plants is rebuilt. The special
treatment
method of performing foliar treatment to the club root diseased plants
restores the
vitality of the affected plants. The application of this technology in the
field can
significantly reduce the loss caused by the disease, make the survival rate of
the
diseased plants reach more than 90%, and increase the yield by more than 60%.
The growth promoter in the present invention combines indolebutyric acid,
naphthylacetic acid, humic acid, boron and plant growth agent according to
appropriate components and proportions based on the principle of the
synergistic
effect of all components, can rebuild the water and nutrient absorption
function of the
root system of the club root diseased plants by selecting the special
sensitive period of
the plants, and restore the normal growth of the diseased plants which are
dying. The
growth promoter is applied by adopting a foliar spraying method at the early
bolting
stage of oilseed rape , when the field soil temperature is higher than the
atmospheric
temperature, or at the moment that the club root diseased plants of the
cruciferous
crops still have 1/5 normal roots. Compared with the traditional way of
application at
roots (it is required to be used within specific time, the duration of which
cannot
exceed 3 days), the use time range is wider, the operation is simpler and the
practicability is stronger.
Preferably, the amount of used indolebutyric acid is 0.3-0.5g/mu, and the
amount of
used water is 40-50L/667m2. Correspondingly, the amount of used naphthylacetic
acid
is 0.3-0.5g/667m2; the amount of used humic acid is 15-20g/667m2; the amount
of
used boron is 10-20g/667m2; and the amount of used plant nutrient is 30-
50g/667m2.
Compared with application at roots in the prior art, the amounts of the used
chemicals
are greatly reduced and the costs of the chemicals are also greatly reduced.
The present invention provides a growth promoter for restoring the root
absorption
function and preventing and treating club root diseases of cruciferous crops.
On the
one hand, it can meet the requirements on nutrients for the growth of
cruciferous
crops such as oilseed rape. On the other hand, it can induce the root growth
through
exogenous stimulation, rebuild the normal physiological function of the root
system
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of the diseased plants and restore the vitality of the diseased plants which
are dying. It
is applicable to the prevention and treatment of the club root disease of the
cruciferous
crops such as oilseed rape and cabbage.
Compared with the prior art, the present invention has the following
advantages:
firstly, the usage amount is small, the effect is remarkable, the benefit is
high, the
application objects are more and the application scope is wide; secondly, the
normal
growth of the diseased plants which are dying can be restored through the
special way
of rebuilding the water and nutrient absorption function of the root system of
the
diseased plants, so that the survival rate of the diseased plants can reach
more than
90%, and the yield can be increased by more than 60%, the yield of oilseed
rape and
other cruciferous crops is guaranteed, and the treatment effect on the club
root disease
is outstanding and stable; thirdly, the technical bottleneck that the club
root diseased
plants are difficult to survive and treat is overcome, it is free of chemical
pesticides,
environment-friendly, and convenient and quick to use, and compared with
traditional
root prevention and treatment method, the costs of chemicals and labor are
reduced by
more than 80%; and fourthly, the effect of foliar application is not affected
by
geological conditions and soil environment, the potential risks of food safety
and
environmental pollution caused by the application of chemical pesticides are
reduced
in a large scale, and the social, economic and ecological benefits are
remarkable.
Description of the Examples
The present invention will be further described below in combination with the
examples.
Example 1
A growth promoter comprised the following components based on the amount of
effective components per 667m2 of oilseed rape:
Indolebutyric acid 0.5g;
Naphthylacetic acid 0.5g;
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Date Recue/Date Received 2020-05-15
Humic acid 20g;
Boron element (borax B) 20g;
Plant nutrient (N:P:K = 3:2:1) 50g.
When applied, the above growth promoter was mixed with 50kg of water for full
dissolution and then the solution was sprayed for 667m2.
Example 2
A growth promoter comprised the following components based on the amount of
effective components per mu of oilseed rape:
Indolebutyric acid 0.3g;
Naphthylacetic acid 0.3g;
Humic acid 15g;
Boron element (borax B) 10g;
Plant nutrient (N:P:K = 3:2:1) 30g.
When applied, the above growth promoter was mixed with 50kg of water for full
dissolution and then the solution was sprayed for 667m2.
Example 3
A growth promoter comprised the following components based on the amount of
effective components per 667m2 of oilseed rape:
Indolebutyric acid 0.4g;
Naphthylacetic acid 0.4g;
Humic acid 16g;
Boron element (borax B) 15g;
Plant nutrient (N:P:K = 4:1:1) 40g.
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Date Recue/Date Received 2020-05-15
When applied, the above growth promoter was mixed with 50kg of water for full
dissolution and then the solution was sprayed for 667m2.
Example 4
A growth promoter comprised the following components based on the amount of
effective components per 667m2 of oilseed rape:
Indolebutyric acid 0.3g;
Naphthylacetic acid 0.5g;
Humic acid 20g;
Boron element (borax B) 10g;
Plant nutrient (N:P:K = 3:2:1) 45g.
When applied, the above growth promoter was mixed with 50kg of water for full
dissolution and then the solution was sprayed for 667m2.
Example 5
A growth promoter comprised the following components based on the amount of
effective components per 667m2 of oilseed rape:
Indolebutyric acid 0.5g;
Naphthylacetic acid 0.3g;
Humic acid 15g;
Boron element (borax B) 20g;
Plant nutrient (N:P:K = 3:2:1) 30g.
When applied, the above growth promoter was mixed with 50kg of water for full
dissolution and then the solution was sprayed for 667m2.
Comparative example 1
A growth promoter only comprised 16g of humic acid.
Date Recue/Date Received 2020-05-15
When applied, the above growth promoter was mixed with 50kg of water for full
dissolution and then the solution was sprayed for 667m2.
Comparative example 2
A growth promoter only comprised 0.4g of indolebutyric acid.
When applied, the above growth promoter was mixed with 50kg of water for full
dissolution and then the solution was sprayed for 667m2.
Comparative example 3
A growth promoter only comprised 0.4g of naphthylacetic acid.
When applied, the above growth promoter was mixed with 50kg of water for full
dissolution and then the solution was sprayed for 667m2.
Comparative example 4
A growth promoter only comprised 0.4g of boron element.
When applied, the above growth promoter was mixed with 50kg of water for full
dissolution and then the solution was sprayed for 667m2.
Comparative example 5
No chemical was added in this comparative example and only clean water was
sprayed.
Experimental verification
In November 2017, in Xigao Town, Guanghan, 30 rape (at the 13-leaves stage)
fields
with high incidence of club root disease (the area of each field was 667m2)
were
selected for parallel test. The selection standard of test fields was that
more than 80%
of oilseed rape plants were infected with the club root disease.
The treatment method was as follows: three test fields were randomly selected
to be
sprayed with the water/solution in examples 1-5 and comparative examples 1-5
by
means of foliar spraying, i.e., the chemical in example 1 was sprayed to three
fields,
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Date Recue/Date Received 2020-05-15
and so on. The test results were averaged.
See Table 1 for the test results.
Table 1 Test results
Number of Number of Increase of plant Increase of yield per
diseased surviving height (cm) 667m2 (kg)
plants plants
Example 1 6510 5530 1.5 51
Example 2 6460 5550 1.6 53
Example 3 6430 5790 2.1 65
Example 4 6550 5560 1.7 55
Example 5 6390 5560 1.6 57
Comparative
6400 2300 0.3 15
example 1
Comparative
6510 2130 0.5 13
example 2
Comparative
6450 1960 0.3 16
example 3
Comparative
6490 1190 0.2 9
example 4
Comparative
6500 350
example 5
The above examples are only preferred examples of the present invention and
are not
used for limiting the present invention. Any modification, equivalent
replacement and
improvement made within the spirit and principle of the present invention
shall be
included in the protection scope of the present invention.
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