Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
USE OF SEDAXANE TO INCREASE THE NUMBER OF NODULES ON A PLANT ROOT
The present invention relates to the use of sedaxane in the production of a
plant having an
increased number of nodules on its roots. In particular, the invention relates
to the use of
sedaxane in the production of a soybean plant having a greater number of root
nodules.
The incorporation of atmospheric Nitrogen (N2) to form nitrogenous organic
compounds is
referred to generally as Nitrogen Fixation. In plants, symbiotic nitrogen
fixation occurs in
the root nodules of, typically leguminous, plants whereby bacteria called
Rhizobia,
otherwise free-living in the soil, infect the roots and colonize cortical
cells. The bacteria
use carbohydrate supplied via the plant's phloem, providing in turn
nitrogenous products to
the plant supplied via the xylem. Rhizobia belong to the families of
Rhizobiales and
Burkholder/ales, the most important species belong to the genera Rhizobinin
and
Bradyrhizobi urn, but many other species in several other genera of the
Rhizobiales or
Bnrkholderiales have been reported to fix atmospheric nitrogen.
Plants which can efficiently utilize the nitrogen fixation process are
desirable in a
commercial farming context since they can reduce the amount of supplemental
fertilizer
otherwise needed to obtain a reasonable yield.
With the world's population increasing, there remains a need to generate even
more
efficient methods for maximising the output from the world's increasingly
valuable and
precious agricultural land.
It has now surprisingly been found that the fungicide sedaxane can increase
the number of
nodules on the roots of plants, thereby leading to increased opportunity for
nitrogen fixing
bacterium, such as Rhizobann or Bradyrhizobium, colonization leading to
increased
nitrogen availability within the plant.
According to the present invention there is provided the use of sedaxane (SDX)
to increase
the number of nodules on the roots of a plant via application of said SDX to a
plant and/or
the locus thereof and/or plant propagation material and then growing said
plant or
propagation material wherein the number of nodules on the roots of said plant
is higher
than the number of nodules on the roots of an untreated control like-plant.
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Sedaxane is a pyrazole carboxamide fungicide: 3-Difluoromethyl-l-methyl-IH-
pyrazole-4-
carboxylic acid (2-bicyclopropy1-2-yl-phenyl)-amide having the formula:
FOG
F-kH
N,
CH,
It, and its trans and cis isomeric forms, namely:
sedaxane (trans) sedaxane (cis)
F 0 F 0
,H H
H N
/
C H3 C H 3
are also described in various published International Patent Applications
including:
W003/074491, W02006/015865, W02007/090623, W02007/131678, W02008/000377,
W02008/003403, W02009/098218, W02010/000790 and Research Disclosure [(2006),
507(July), P783-P791 (Number 507002) CODEN: RSDSBB; ISSN: 0374-4353].
A further preferred embodiment of the present invention is represented by the
use of
sedaxane or a method which uses sedaxane to increase the number of nodules on
the roots
of a plant wherein the sedaxane is present in a composition which comprises a
mixture of
racemic trans-isomers and racemic cis-isomers of sedaxane, in a trans/cis-
ratio of from I :
1 to 100: I, for example 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1,
20:1, 50:1 or 100 :
1. Further preference is given to ratios from 2:1 to 100:1, more preferably
4:1 to 10:1. In a
further embodiment the sedaxane is applied to the plant and/or the locus
thereof and/or
plant propagation material in a formulation wherein the sedaxane is present in
the
formulation at from 65-99% of the trans isomer.
The present invention further provides the use of a compound according to
formula (I):
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0
Ri R2
CH 3
(0,
wherein
R1 is trifluoromethyl or difluoromethyl and
R/ is hydrogen or methyl; or a tautomer of such a compound,
to increase the number of nodules on the roots of a plant via application of
said compound
to a plant and/or the locus thereof and/or plant propagation material and then
growing said
plant or propagation material wherein the number of nodules on the roots of
said plant is
higher than the number of nodules on the roots of an untreated control like-
plant.
The present invention still further provides a method for the production of a
plant having a
higher number of nodules on the roots of said plant, said method comprising
applying
sedaxane to said plant and/or the locus thereof and/or plant propagation
material and then
growing said plant or propagation material wherein the number of nodules on
the roots of
said plant is higher than the number of nodules on the roots of an untreated
control like-
plant.
When in use, any composition containing sedaxane may also comprise additional
active
ingredients, e.g. insecticide, a fungicide, nematicide, synergist, herbicide,
plant growth
regulator or a "plant health" promoting compound. Examples of active
ingredients that can
be added to the sedaxane containing composition include all compounds listed
in The
Pesticide Manual (British Crop Production Council ¨ ISBN No. 9781901396188)
available
at www.bcpc.org. Particularly preferred mixtures include those disclosed in
W02006/015865 and W02007/090623.
Where required, application of the sedaxane and a further active ingredient,
(e.g. as a
"combination") may be in a single "ready-mix" form, such as a ready-to-use
foimulation
comprising the two components in a fixed ratio; or in a combined spray or
application
mixture composed of separate formulations of the individual active ingredient
components,
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(e.g. a "tank-mix"); or in a combined use of the individual active ingredients
when applied
in a common spray plan or schedule in a sequential manner, i.e. one after the
other within a
reasonably short period, (e.g. within a few hours of each other). When applied
in separate
sprays or seed applications following each other, the order of applying the
active
ingredients is not essential for achieving the effect according to the present
invention.
The present invention still further provides the use or method as described
above wherein
said plant or propagation material is soybean.
The present invention still further provides the use or method as described
above wherein
said propagation material is seeds.
The present invention still further provides the use or method as described
above wherein
said sedaxane is applied to said plant and/or the locus thereof and/or plant
propagation
material in such an amount that the number of nodules present on the roots of
the plant is at
least 5% higher than the number of nodules on the roots of an untreated
control like-plant.
The present invention still further provides the use or method as described
above wherein
said sedaxane is applied to said plant and/or the locus thereof and/or plant
propagation
material in such an amount that the number of nodules present on the roots of
the plant is at
least 10% higher than the number of nodules on the roots of an untreated
control like-plant.
The present invention still further provides the use or method as described
above wherein
said sedaxane is applied to said plant and/or the locus thereof and/or plant
propagation
material in such an amount that the number of nodules present on the roots of
the plant is at
least 50% higher than the number of nodules on the roots of an untreated
control like-plant
The present invention still further provides the use or method as described
above wherein
said sedaxane is applied to said plant and/or the locus thereof and/or plant
propagation
material in such an amount that the number of nodules present on the roots of
the plant is at
least 60% higher than the number of nodules on the roots of an untreated
control like-plant.
The present invention still further provides the use or method as described
above wherein
said plant is grown in the presence of Rhizobizun sp. and/or Bradyrhizobium
sp..
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The present invention still further provides the use or method as described
above wherein
the plant contains a higher percentage of Nitrogen in the foliage when
compared with an
untreated control-like plant.
The present invention still further provides the use as described above
wherein said plant is
grown in the presence of Rhizoctonia sp..
The present invention still further provides the use as described above
wherein said plant is
grown in the absence of Rhizoctonia sp..
Rhizoctonia is a genus of anamorphic fungi in the order Cantharellales.
Rhizoctonia
species are plant pathogens causing commercially important crop diseases,
particularly
root diseases.
"Plant" and "Plants" according to the invention embrace those plants which are
capable of
forming nodules upon the roots which nodules can be colonized by Rhizobium sp.
or
Bradyrhizobium sp.. Typically such plants comprise leguminous plants, of the
family
Fabaceae. Examples of leguminous plants include beans, lentils, peas,
soybeans, castor oil
plants, cocoa beans or groundnuts. Examples of legumes commonly consumed by
animals
include: Alfalfa; Asparagus Bean; Asparagus Pea; Baby Lima Bean; Black Bean;
Black
Eyed Peas; Black Turtle Bean; Boston Bean; Boston Navy Bean; Broad Bean;
Cannellini
Bean; Chickpeas; Chili Bean; Coco Bean; Cranberry Bean; Dwarf Beans; Egyptian
Bean;
Egyptian White Broad Bean; English Bean; Fava Bean; Field Pea; French Green
Beans;
Great Northern Bean; Green Beans; Green and Yellow Peas; Kidney Beans;
Lentils;
Lespedeza; Liquorice; Lima Bean; Madagascar Bean; Mexican Black Bean; Mexican
Red
Bean, Molasses Face Bean; Mung Bean; Mung Pea; Navy Bean; Pea Bean; Peanuts,
Peruvian Bean, Pinto Bean; Red Bean; Red Clover; Red Eye Bean; Red Kidney
Bean; Rice
Bean, Runner Bean; Scarlet Runner Bean; Small Red Bean, Small White Bean, Snow
Peas; Southern Peas; Sugar Snap Peas; Soybean, Wax Bean, White Clover; White
Kidney
Bean, and White Pea Bean. These lists do not represent any limitation.
The terms "plant' and "plants" also includes plants which have been rendered
resistant to
herbicides, insecticides, fungicides or have been modified in some other way
such as to
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enhance yield, drought tolerance or quality via conventional methods of
breeding or by
genetic engineering methods. Any genetically modified plants used in
accordance with the
present invention may have been modified via recombinant nucleic acid
techniques well
known to the person skilled in the art. For example, the "plant" and "plants"
according to
the invention include those soybean plants which have been bred via
conventional breeding
methods to be resistant to Asian soybean rust. Such soybean plant varieties
are termed
"Inox" varieties and include the varieties registered in Brazil under the
Plant Variety
Protection Laws under denominations TMG 801 and TMG 803.
The term "locus" of a plant as used herein is intended to embrace the place on
which the
plants are growing, where the plant propagation materials are sown or where
the plant
propagation materials will be placed into the soil. An example for such a
locus is a field,
on which crop plants are growing.
The term "plant propagation material" is understood to denote generative parts
of the plant,
such as seeds, which can be used for the multiplication of the latter, and
vegetative
material, such as cuttings or tubers. The term includes seeds (in the strict
sense), roots,
fruits, tubers, bulbs, rhizomes and parts of plants. Germinated plants and
young plants
which are to be transplanted after germination or after emergence from the
soil, may also
be mentioned. These young plants may be protected before transplantation by a
total or
partial treatment by immersion. Preferably "plant propagation material" is
understood to
denote seeds.
The term "untreated control-like plant" denotes a plant, the locus thereof or
plant
propagation material which is subjected to substantially identical conditions
to the plant,
the locus thereof or plant propagation material according to the invention
save for the
untreated control-like plant (or locus thereof or plant propagation material
as applicable)
has not been treated with sedaxane. The person skilled in the art is well
aware how to
perform properly controlled experiments and thus can make a comparison
assessment by
growing two groups of plants of the same species/variety under the same
conditions
wherein only one of said groups (being the plant, locus thereof or propagation
material)
has been treated with sedaxane thereby enabling said skilled person to
ascertain the effect
on root nodulation of the sedaxane treated plant in comparison with the
untreated control-
like plant.
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The terms "root" and "roots" should be interpreted to mean the organ of the
plant that
typically lies below the surface of the growth media, such as the soil Thus,
in the context
of determining the number of nodules this is calculated by determining the
number of
nodules within the entire mass of what would typically be considered as the
plant's roots.
The term "sedaxane" may be interchanged with "SDX".
In a still further aspect, the present invention also provides the use or
method as described
above to additionally improve the plant's health.
For example, advantageous properties that may be additionally achieved in
combination
with the increased number of nodules on the roots as described above include:
improved
crop characteristics including: emergence, crop yield, protein content,
increased vigour,
faster/delayed maturation, increased speed of seed emergence, improved
nutrient
utilization efficiency, improved nitrogen utilization efficiency, improved
water use
efficiency, improved oil content and /or quality, improved digestibility,
faster/more even
ripening, improved flavor, improved starch content, more developed root system
(improved root growth), improved stress tolerance (e.g. against drought, heat,
salt, light,
UV, water, cold), reduced ethylene (reduced production and/or inhibition of
reception),
tillering increase, increase in plant height, bigger leaf blade, less dead
basal leaves,
stronger tillers, greener leaf color, pigment content, photosynthetic
activity, less input
needed (such as fertilizers or water), less seeds needed, more productive
tillers, earlier
flowering, early grain maturity, less plant verse (lodging), increased shoot
growth,
enhanced plant vigor, increased plant stand and early and better germination.
Advantageous properties obtained, especially from treated seeds, include, for
example,
improved germination and field establishment, better vigor and more
homogeneous field
establishment.
Advantageous properties obtained, especially from foliar and/or in-furrow
application
include, for example, improved plant growth and plant development, better
growth, more
tillers, greener leaves, larger leaves, more biomass, better roots, improved
stress tolerance
of the plants, more grain yield, more biomass harvested, improved quality of
the harvest
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(content of fatty acids, metabolites, oil etc), more marketable products (e.g.
improved size),
improved process (e.g. longer shelf-life, better extraction of compounds),
improved quality
of seeds (for being seeded in the following seasons for seed production); or
any other
advantages familiar to a person skilled in the art.
In a particular embodiment of the invention the use or method as described
above provides
a plant having a higher number of nodules on its roots, when compared with the
roots of a
control like-plant, which plant also exhibits improved plant health in
addition to the higher
number of nodules on its roots.
When applied to the plants in accordance with the use / method of the
invention, the
sedaxane (a.i.) is typically applied at a rate of 5 to 2000 g a.i./ha,
particularly 10 to 1000 g
a.i./ha, e.g. 50, 75, 100 or 200 g a.i./ha, typically in association with 0.5
to 1000 g/ha,
preferably 1 to 750 g/ha, more preferably 2.5 to 500 g/ha, more preferably 5
to 300 g/ha,
more preferably 7.5 to 200 g/ha of a.i..
In agricultural practice the application rates of the compositions according
to the use /
method of the invention depend on the type of effect desired, and typically
range from 20
to 4000 g of total composition per hectare.
When sedaxane is used for treating seed, rates of 0.001 to 50 g of sedaxane
per kg of seed,
preferably from 0.01 to lOg per kg of seed, are generally sufficient.
The composition containing sedaxane and any mixtures with other compounds/
active
ingredients as described above may be employed as a foimulation in any
conventional
form, for example in the form of a twin pack, a powder for dry seed treatment
(DS), an
emulsion for seed treatment (ES), a flowable concentrate for seed treatment
(FS), a
solution for seed treatment (LS), a water dispersible powder for seed
treatment (WS), a
capsule suspension for seed treatment (CF), a gel for seed treatment (GF), an
emulsion
concentrate (EC), a suspension concentrate (SC), a suspo-emulsion (SE), a
capsule
suspension (CS), a water dispersible granule (WG), an emulsifiable granule
(EG), an
emulsion, water in oil (EO), an emulsion, oil in water (EW), a micro-emulsion
(ME), an oil
dispersion (OD), an oil miscible flowable (OF), an oil miscible liquid (OL), a
soluble
concentrate (SL), an ultra-low volume suspension (SU), an ultra-low volume
liquid (UL), a
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technical concentrate (TK), a dispersible concentrate (DC), a wettable powder
(WP) or
any technically feasible formulation in combination with agriculturally
acceptable
adjuvants.
Such mixtures and compositions may be produced in a manner well known to the
person
skilled in the art, e.g. by mixing the active ingredients with at least one
appropriate inert
formulation adjuvant for example, diluents, solvents, fillers and optionally
other
formulating ingredients such as surfactants, biocides, anti-freeze, stickers,
thickeners and
compounds that provide adjuvancy effects. Inert ingredients especially
biocides must be
carefully selected by the person skilled in the art such that they do not
inhibit or damage
the nitrogen fixing bacteria. Also slow release formulations may be employed
where long
lasting efficacy is intended. Particularly, formulations to be applied in
spraying forms, such
as water dispersible concentrates (e.g. EC, SC, DC, OD, SE, EW, EO and the
like),
wettable powders and granules, may contain surfactants such as wetting and
dispersing
agents and other compounds that provide adjuvancy effects, e.g. the
condensation product
of formaldehyde with naphthalene sulphonate, an alkylarylsulphonate, a lignin
sulphonate,
a fatty alkyl sulphate, and ethoxylated alkylphenol and an ethoxylated fatty
alcohol.
Formulation ingredients well known to the person skilled in the art may, for
example,
include those formulation ingredients that do not have any significant
biological activity,
or have no biological activity. They include, for example, diluents, solvents,
fillers,
surfactants, biocides, anti-freeze, stickers, thickeners and compounds that
provide
adjuvancy effects.
A seed dressing formulation is applied in a manner known to the person skilled
in the art,
e.g. as an aqueous suspension or in a dry powder form having good adherence to
the seeds.
Such seed dressing formulations are known in the art Seed dressing
formulations may
contain the single active ingredients or the combination of active ingredients
in
encapsulated form, e.g. as slow release capsules or microcapsules. A typical a
tank-mix
formulation for seed treatment application comprises 0.25 to 80%, especially 1
to 75 %, of
the desired ingredients, and 99.75 to 20 %, especially 99 to 25 %, of a solid
or liquid
auxiliaries (including, for example, a solvent such as water), where the
auxiliaries can be a
surfactant in an amount of 0 to 40 %, especially 0.5 to 30 %, based on the
tank-mix
formulation. A typical pre-mix formulation for seed treatment application
comprises 0.5 to
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99.9 %, especially 1 to 95 %, of the desired ingredients, and 99.5 to 0.1 %,
especially 99 to
5 %, of a solid or liquid adjuvant (including, for example, a solvent such as
water), where
the auxiliaries can be a surfactant in an amount of 0 to 50 %, especially 0.5
to 40 %, based
on the pre-mix formulation.
5
In general, the formulations include from 0.01 to 90% by weight of active
agent, from 0 to
20% agriculturally acceptable surfactant and 10 to 99.99% solid or liquid
formulation
inerts and adjuvant(s), the active agent consisting of at least sedaxane and
optionally other
active agents, including those mentioned above and/or microbiocides or
conservatives or
10 the like. Concentrated forms of compositions generally contain in between
about 2 and
80%, preferably between about 5 and 70% by weight of active agent. Application
forms of
formulation may for example contain from 0.01 to 20% by weight, preferably
from 0.01 to
5% by weight of active agent. Whereas commercial products will preferably be
formulated
as concentrates, the end user will normally employ diluted formulations.
The Example which follows serves to illustrate the invention. The invention is
not limited
to this Example.
Example
The following experiment was carried in the laboratory and the greenhouse.
Rhizoctonia
isolate used in this experiment was originated from the city of Dourados, Mato
Grosso do
Sul state. Isolate used was Solo 44.
After receiving the isolates, they were purified and propagated in PDA growth
medium.
Finally they were grown in chambers with controlled temperature (22 +/- 1 C)
and
controlled daylight time (12h light / 12h dark) for 7 days.
Treatments assessed in the experiment are in accordance with Table 1:
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Table 1
Number Inoculation Chemical treatment Rate of chemical (ml of
product/100kg of seeds)
1
2 sedaxane 200
3 Rhizobia ¨ No
Rhizoctonia - Yes
4 Rhizobia ¨ No sedaxane 200
Rhizoctonia - Yes
Rhizobia ¨ Yes
Rhizoctonia - Yes
6 Rhizobia ¨ Yes sedaxane 200
Rhizoctonia - Yes
7 Rhizobia ¨ Yes
Rhizoctonia - No
8 Rhizobia ¨ Yes sedaxane 200
Rhizoctonia - No
Formulation used was an FS (flowable for seed treatment) containing 500g/L of
sedaxane.
Parameters assessed:
5 - Fresh matter of aerial part of plants (g/plant);
- Fresh matter of roots (g/plant);
- Number of nodules;
- Dry matter of nodules;
- Total N content on leaves;
Assessment of Bradyrhizobium infectivity:
Soybean plants from variety "Roos" were grown in greenhouse, after their seeds
were
treated with fungicide sedaxane according to treatments list. Immediately
after treatment
with the chemical (following guidelines from Agriculture Ministry), the seeds
were
inoculated with commercial inoculant Cell Techil containing isolates SEMIA
5079 and
SEMIA 5080 of Bradyrhizobium japonicurn, also according to treatments list.
Plants were grown in modified Leonard pots (Vincent, 1970 J.M. Vincent, A
manual for
the practical study of root-nodule bacteria, IBP Handb. No. 15, Blackwell,
Oxford (1970),
p. 164.) filled with a planting medium composed by a mixture of vermiculite,
washed sand
and grilled charcoal in a proportion 3:1:1 respectively. Pots were slightly
watered with
distilled water, covered with brown paper and sterilized at 121 C and latm
pressure for 1.5
hours.
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After the pots cooled, disks of PDA growth medium with 2.5cm diameter,
infected with
Rhizoctonia, were placed on top of some amount of the planting medium in the
pots,
according to the treatments list Than the pots were completely filled with
planting medium
(3cm approximately more), then the seeds were sowed, in a way they were not in
direct
contact with Rhizoctoni a inoculum.
Pots were periodically watered with McKnight nutritive solution, without
Nitrogen,
alternating with distilled water.
After germination, plantules germinated and dead were counted. Then excessive
plantules
were removed in order to keep only one plantule per pot. Plantules were daily
observed,
determining their development and symptoms of any disease.
Efficiency of the Bradyrhizobium in Nitrogen fixation
At flowering, soybean plants were harvested, the aerial part was separated
from roots and
dried in oven at 65 C until constant weight. Then dry matter of this fraction
was
determined.
Then this dry matter was grilled and the total amount of Nitrogen was
determined via the
Digestion and Titration Method (Microkjedahl). Jackson, 1964 M.L. Jackson,
Soil
Chemical Analysis, Prentice Hall Inc. Englewood Cliffs, New York (1964) pp. 86-
92.
Roots were washed with water to take soil away, then nodules were detached.
Roots were
dried at 65 C until constant weight. Then dry matter of this fraction was
determined.
Nodules were counted, then dried in the oven at 65 C until constant weight.
Then dry
matter of this fraction was determined.
Statistical analysis
Trial was carried under randomized blocks design (8 treatments and 5
replicates). Data
variances were analyzed. F test was significant at 5%, and treatment means
were compared
with Tukey test at 5%.
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Results
Table 2
Effect of treatments on the number and dry matter of nodules
Number Number of nodules Nodules dry matter (mg/g)
1 21.8b 0.124b
2 24.6b 0.13b
3 15.4b 0.1 b
4 18.2 b 0.098 b
75.5a 0.434a
6 80a 0.408a
7 72a 0.386a
8 113a 0.524a
5 Means followed with same letters are not different at Tukey test (5%
significance)
Table 3
Effect of treatments on Nitrogen content, dry matter of aerial part and roots
Number Nitrogen (%) Dry matter aerial part Dry matter roots
(g/plant) (g/plant)
1 1.984 b 1.598 b 0.906b
2 2.866b 1.640b 1.022b
3 2.576b 1.236 b 0.806b
4 2.562b 1.226b 0.862b
5 3.376 ab 3.550a 1.868a
6 4.020 a 4.158 a 1.800 a
7 3.266 ab 3.304 a 1.546 ab
8 3.980 a 4.406 a 1.818 a
Means followed with same letters don't differ at Tukey test (5% significance)
