Selectivity of Pre-Emergence Herbicides Applied at Sowing
or Early Post-Emergence of Soybean
Juliana Ranakoski Barbosa1,
Alfredo Junior Paiola Albrecht2, Leandro Paiola Albrecht2,
Fernanda Cristina Garcia1, Leandro Gervazio Mori3, André
Felipe Moreira Silva4*, Marcio Favoretto5 and Emanuele
Scapim Piccin2
1State
University of Maringá, Umuarama, Paraná, Brazil
2Federal
University of Paraná, Palotina, Paraná, Brazil
3Pontifical
Catholic University of Paraná, Toledo, Paraná, Brazil
4Crop Pesquisa, Maripá, Paraná, Brazil
5Fartura Insumos Agrícolas Ltda., Juranda, Paraná, Brazil
*For correspondence: afmoreirasilva@hotmail.com
Received
24 January 2023; Accepted 21 April 2023; Published 28 May 2023
Post-emergence
application of imazethapyr/flumioxazin, sulfentrazone/diuron, clomazone or
s-metolachlor is believed to cause injury to soybeans. The objective was to evaluate
the selectivity of these herbicides applied at sowing, at 7 or 14 days after
sowing (DAS) of soybean. The trial was conducted at two locations in Jesuítas
and at one location in Ubiratã, state of Paraná (PR), Brazil. The treatments
were arranged in a 5 × 3 factorial scheme, the herbicides
imazethapyr/flumioxazin, sulfentrazone/diuron, clomazone, s-metolachlor and
non-treated control were used, which were applied at three periods (sowing, 7
and 14 DAS). Soybean injury symptoms, plant height and soybean yield were
evaluated. The highest phytotoxic potential (up to 56.2%) was observed for the
application of imazethapyr/flumioxazin and sulfentrazone/diuron at 14 DAS. The
application of clomazone and s-metolachlor were selective in soybean, at
pre-emergence, at 7 and 14 DAS. Imazethapyr/flumioxazin or sulfentrazone/diuron
at 14 DAS caused significant injury to soybean including reducing plant height
and, for sulfentrazone/diuron, a reduction in yield was found for application
at 14 DAS compared to 7 DAS. The application of the herbicides in pre-sowing,
at 7 and 14 DAS was selective for soybean except sulfentrazone/diuron at 14
DAS, which reduced soybean yield. © 2023 Friends Science Publishers
Keywords: Injury;
Imazethapyr/flumioxazin; Sulfentrazone/diuron; Clomazone; S-metolachlor;
Agronomic performance
Introduction
Herbicides with pre-emergence effects
are very important in the management of weeds that are difficult to control,
and it is important that the residual effect lasts until the vegetative
development of the soybean. In this sense, their application has been
investigated, even in soybean post-emergence to obtain a greater residual
effect within the soybean growing cycle (Oliveira et al. 2017; Chahal et
al. 2018; Sarangi and Jhala 2019).
Mixtures of herbicides with different mechanisms of action are often
recommended as an effective tool for weed management especially in relation to
herbicide resistance in weeds (Kniss et al. 2022). With the aim of
improving efficacy and expanding the spectrum of action, some companies have
introduced pre-emergence mixtures on the market. For a pre-emergence
application, it is necessary to consider some factors such as environmental
conditions and soil properties to define a safe dose (Barroso et al.
2021).
Pre-emergence herbicides must be selective for soybean plants, selectivity
is the differentiated response the crop presents to the application of a given
herbicide, which may or may not suffer injuries. The level of injuries can be
changed according to the application conditions, physiological status, plant
morphology and plant recovery capacity after herbicide application through
inactivation/ metabolization of the molecule (Carvalho et al. 2009;
Nandula et al. 2019).
Studies report the selectivity of
pre-emergence herbicides in soybean (Belfry et al. 2015; Belfry
et al. 2016; Fornazza et al. 2018; Hay et al. 2019). However, few studies addressed the selectivity of these
herbicides in the early post-emergence of soybeans, especially in Brazil. Neto et al. (2009) observed that the application of glyphosate in a mixture with
the pre-emergence flumioxazin or s-metolachlor at the V1 stage
(phenological stage: first trifoliolate: one set of unfolded trifoliolate
leaves) of soybean caused injury to the crop with growth delay and inter-row
closure, however, it did not interfere with soybean yield.
Many
products have been recommended for application in pre-sowing soybean (Dalazen et al. 2020; Albrecht et al. 2021, 2022). In
this sense, the acetolactate synthase (ALS) inhibitor herbicides, such as
imazethapyr can be highlighted. Protoporphyrinogen oxidase (PPO) inhibitor
herbicides are also important, such as flumioxazin or sulfentrazone, also
herbicides that inhibit the biosynthesis of very-long-chain fatty acids
(VLCFA), such as s-metolachlor. Another important herbicide is clomazone, which
is an inhibitor of carotenoid biosynthesis.
However,
there is a need for studies that evaluate the selectivity of these herbicides
in soybean post-sowing. Early post-emergence application of
imazethapyr/flumioxazin, sulfentrazone/diuron, clomazone or s-metolachlor is
believed to cause injury to soybeans. Therefore, the objective was to evaluate
the selectivity of these herbicides applied at sowing, at 7 or 14 days after
soybean sowing (DAS).
Materials and
Methods
Trials
description and experimental design
The experiment was carried out in
Jesuítas (trials 1 and 2, 24°27'59"S 53°25'32"W) and Ubiratã (trial
3, 24°16'55.7"S 53°30'47.9"W), state of Paraná (PR), Brazil. The
three trials were carried out during 2020–2021 growing season. Trials 1 and 2
were located in clayey soil (18.75% sand, 17.5% silt, 63.75% clay), with
organic matter (OM) of 24.7 g dm-3, sum of basis (SB) of 9.1 cmolc
dm-3, cation exchange capacity (CEC) of 15.8 cmolc dm-3 and
basis saturation (V) of 57.6%. Trial 3 was carried out in very clayey soil
(17.5% sand, 17.5% silt, 65% clay), with OM of 29.5 g dm-3, SB of
7.9 cmolc dm-3, CEC of 14.1 cmolc dm-3 and V of 56%.
According to the Köeppen classification, the climate of the region is
subtropical (Cfa), and the meteorological conditions during the trials are
illustrated in Fig. 1.
This was a randomized block design with four replications with
factorial arrangement (5 × 3). Five treatments were used for the herbicide
factor: imazethapyr/flumioxazin (100/50 g acid equivalent [ae]/active
ingredient [a.i.] ha-1, Zethamaxx®), sulfentrazone/diuron
(245/490 g a.i. ha-1, Stone®), clomazone (900 g a.i. ha-1,
Reactor® 360 CS), s-metolachlor (1,440 g a.i. ha-1, Dual
Gold®) and the untreated control. Herbicides were applied in three
periods: at sowing, at 7 and 14 DAS. All plots were kept free of weed
interference with the use of manual weeding carried out at 7 and 14 DAS before
the application of herbicides and were no longer necessary until the soybean
harvest. This was done to eliminate competition between weeds and soybeans, so
that any effects of treatments on soybeans would not be due to the level of
effectiveness in controlling weeds.
The experimental units consisted of plots of 6 soybean rows (2.7 m × 5
m long), under no-till system, with spacing between rows of 0.45 m and 13 seeds
m-1. Soybean cultivar BMX 64i61RSF was used in trial 1 and cultivar
BS 2606 in trial 2 with sowing date of October 24, 2020, the areas were fallow
after the maize harvest. In trial 3, the cultivar CZ 58B28 was sown on
September 25, 2020 in a field previously grown with oats.
Herbicide
application
Fig. 1: Rainfall, maximum and minimum
temperature at experimental. PR, Brazil, 2020-2021 crop season
Table 1: Application dates and weather
conditions at the time of experiment applications
Trial |
Period |
Date |
T |
Wind |
RH |
|
|
|
ºC |
km h-1 |
% |
1 and 2 |
Sowing |
Oct 24, 2020 |
29.2 |
13 |
54 |
1 and 2 |
7 DAS |
Oct 31, 2020 |
26.1 |
10 |
50 |
1 and 2 |
14 DAS |
Nov 07, 2020 |
32.0 |
8 |
27 |
3 |
Sowing |
Sep 25, 2020 |
25.9 |
9 |
48 |
3 |
7 DAS |
Oct 02, 2020 |
24.0 |
9 |
64 |
3 |
14 DAS |
Oct 09, 2020 |
26.0 |
9 |
62 |
DAS: days after sowing. T: temperature.
RH: relative humidity
Herbicides were applied using a CO2
pressurized backpack sprayer at a constant pressure of 2 bar, equipped with a
bar with 6 fan nozzles (XR 110.02, Teejet®) at a height of 50 cm
from the target with a spray volume of 150 L ha-1. Weather
conditions at the time of application are listed in Table 1. In trials 1 and 2,
at the application period at 7 DAS, soybean was at the VE stage
(emergence – cotyledons have been pulled through the soil surface) and at the
application period at 14 DAS, at the VC stage (unrolled unifoliolate
leaves – unfolding of the unifoliolate leaves). In trial 3, at 7 DAS, soybean
was at the VC stage and at 14 DAS, at the V2 stage
(second trifoliolate - two sets of unfolded trifoliolate leaves).
Assessments
Crop injury symptoms were evaluated in
soybean plants at V4 (fourth trifoliolate), V6–V7
(sixth-seventh trifoliate) and R1 (beginning of flowering – plants
have at least one flower Table 2: Significance level for the variables according to ANOVA, by the F-test
|
|
Crop injury |
Plant height |
Yield |
||
|
|
V4 stage |
V6-V7 stage |
R1 stage |
||
|
|
% |
cm |
kg ha-1 |
||
Trial 1 |
Herbicide |
* |
* |
* |
ns |
ns |
Application period |
* |
* |
* |
* |
* |
|
Interaction |
* |
* |
* |
* |
* |
|
Mean |
4.5 |
3.4 |
3.0 |
110.5 |
4,121 |
|
CV (%) |
27.4 |
25.4 |
41.6 |
4.7 |
7.6 |
|
Trial 2 |
Herbicide |
* |
* |
* |
* |
ns |
Application period |
* |
* |
* |
* |
ns |
|
Interaction |
* |
* |
* |
* |
ns |
|
Mean |
4.4 |
3.3 |
2.9 |
112.4 |
4,663 |
|
CV (%) |
26.5 |
37.0 |
39.4 |
4.0 |
10.8 |
|
Trial 3 |
Herbicide |
* |
* |
* |
ns |
ns |
Application period |
* |
* |
* |
ns |
ns |
|
Interaction |
* |
* |
* |
ns |
ns |
|
Mean |
11.3 |
7.0 |
5.1 |
112.9 |
4,998 |
|
CV (%) |
8.1 |
10.4 |
15.2 |
2.9 |
5.6 |
V4: fourth trifoliolate. V6-V7:
sixth-seventh trifoliate. R1: beginning flowering - plants have at
least one flower on any node
* Significant (P ≤ 0.05), means differ each other by F-test. ns
Non-significant (P > 0.05), means
do not differ each other by F-test
on any node) phenological stages, in
trials 1 and 2, at 35, 42 and 49 DAS, respectively, in trial 3, at 21, 28 and
35 DAS. These evaluations were carried out by visual analysis at each
experimental unit (0 for no injuries, up to 100% for plant death) considering
in this case significantly visible symptoms in the plants according to their
development (Velini et al. 1995).
At the soybean physiological maturity, height was evaluated in 10
plants per plot. For yield, the three central rows of each 3 m long plot were
harvested, the grains were measured for mass with moisture corrected to 13% and
expressed in kg ha-1.
Statistical analysis
Data were tested by analysis of
variance (ANOVA) by F-test (P ≤ 0.05)
separately for each trial. For the levels of both factors, means were compared
by Tukey (1949) test (P ≤ 0.05).
For the analysis, the software Sisvar 5.6 (Ferreira 2011) was used.
Results
F-test
For all crop injury assessments at the
three trials, a significant effect (P ≤
0.05) was detected for both factors and for the interaction. A significant
effect was observed on plant height in trial 1 for application period,
interaction, but not for herbicide. In trial 2, a significant effect was
observed for both the factors and for the interaction on plant height, while in
trial 3, no significant effect was found (P > 0.05) (Table 2).
For soybean yield,
a significant effect was found only for the application period and interaction
in trial 1. For trials 2 and 3, no significant effect was detected for the
factors and interaction (Table 2). The following sections present the outspread
for the variables when a significant effect was found.
Crop injury
In the three trials, the highest
phytotoxic potential was observed for the application of
flumioxazin/imazethapyr and sulfentrazone/diuron at 14 DAS. Crop injury was up
to 56.2%, which was observed at the V4 stage, for the application of
flumioxazin/imazethapyr at 14 DAS in the trial 3. No symptoms of injury were observed
for all the trials and evaluations when the herbicides were applied at soybean
sowing (Table 3, 4 and 5).
The application of s-metolachlor also caused injury to the crop at trial
3 with higher symptoms for the application at 14 DAS. All herbicides caused
some injury in trial 3 when applied at 7 or 14 DAS. In trial 3 during the
applications at 7 DAS, soybean was at the VC stage and at 14 DAS at
the V2 stage, which helps to elucidate the pronounced symptoms of
injury. Soybeans were at a phenological stage closer to the beginning of the
evaluations at V4 (Table 5).
Plant height
For plant height in trials 1 and 2, the
action of flumioxazin/imazethapyr and sulfentrazone/diuron was influenced by
the period of application. A reduction in plant height was observed when these
herbicides were applied at 14 DAS. At trial 2, these herbicides also reduced
plant height compared to s-metolachlor application and untreated control (Table
6).
Soybean yield
An effect on soybean yield was observed
only in trial 3. The sulfentrazone/diuron product was impacted by the
application period with a reduction in yield for the application at 14 DAS
compared to the application at 7 DAS but without differing from other
herbicides. No differences were detected in the other outspreads (Table 7).
Table 3: Crop injury (%) at V4, V6-V7 and R1
soybean plants under herbicide application at sowing, 7 and 14 days after
sowing (DAS). Trial 1
Application period |
Sowing |
7 |
14 |
Sowing |
7 |
14 |
Sowing |
7 |
14 |
DAS |
DAS |
DAS |
|||||||
Herbicide (g ha-1)ª |
Crop injury at V4 |
Crop injury at V6-V7 |
Crop injury at R1 |
||||||
Imazethapyr/flumioxazin (100/50) |
0.0 aA |
0.0 aA |
31.5 bB |
0.0 aA |
0.2 aA |
21.5 bB |
0.0 aA |
0.0 aA |
19.7 bB |
Sulfentrazone/diuron (245/490) |
0.0 aA |
0.0 aA |
34.5 cB |
0.0 aA |
0.2 aA |
27.7 cB |
0.0 aA |
0.0 aA |
24.7 cB |
Clomazone (900) |
0.0 aA |
0.0 aA |
0.2 aA |
0.0 aA |
0.0 aA |
0.5 aA |
0.0 aA |
0.0 aA |
0.0 aA |
S-metolachlor (1.440) |
0.0 aA |
0.0 aA |
0.7 aA |
0.0 aA |
0.0 aA |
0.5 aA |
0.0 aA |
0.0 aA |
0.2 aA |
Non-treated control |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
V4: fourth trifoliolate. V6-V7:
sixth-seventh trifoliate. R1: beginning flowering - plants have at
least one flower on any node
ªRates at acid
equivalent (ae) for imazethapyr, and at active ingredient (a.i.) for other
herbicides
Means followed by the same letter,
lowercase for herbicide and uppercase for application period, do not differ
from each other by Tukey's test at the 5% probability level
Table 4: Crop injury (%) at V4, V6-V7, and R1
soybean plants under herbicide application at sowing, 7 and 14 days after
sowing (DAS). Trial 2
Application period |
Sowing |
7 |
14 |
Sowing |
7 |
14 |
Sowing |
7 |
14 |
DAS |
DAS |
DAS |
|||||||
Herbicide (g ha-1)ª |
Crop injury at V4 |
Crop injury at V6-V7 |
Crop injury at R1 |
||||||
0.0 aA |
0.0 aA |
14.5 cB |
0.0 aA |
0.0 aA |
11.0 bB |
0.0 aA |
0.0 aA |
9.7 bB |
|
Sulfentrazone/diuron (245/490) |
0.0 aA |
0.5 aA |
47.2 dB |
0.0 aA |
0.0 aA |
38.5 cB |
0.0 aA |
0.0 aA |
33.5 cB |
Clomazone (900) |
0.0 aA |
0.0 aA |
0.7 aA |
0.0 aA |
0.0 aA |
0.5 aA |
0.0 aA |
0.0 aA |
0.0 aA |
S-metolachlor (1.440) |
0.0 aA |
0.0 aA |
3.2 bB |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
Non-treated control |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
V4: fourth trifoliolate. V6-V7:
sixth-seventh trifoliate. R1: beginning flowering - plants have at
least one flower on any node
ªRates at acid
equivalent (ae) for imazethapyr, and at active ingredient (a.i.) for other
herbicides
Means followed by the same letter,
lowercase for herbicide and uppercase for application period, do not differ
from each other by Tukey's test at the 5% probability level
Table 5: Crop injury (%) at V4, V6-V7, and R1
soybean plants under herbicide application at sowing, 7 and 14 days after
sowing (DAS). Trial 3
Application period |
Sowing |
7 |
14 |
Sowing |
7 |
14 |
Sowing |
7 |
14 |
DAS |
DAS |
DAS |
|||||||
Herbicide (g ha-1)ª |
Crop injury at V4 |
Crop injury at V6-V7 |
Crop injury at R1 |
||||||
Imazethapyr/flumioxazin (100/50) |
0.0 aA |
3.0 bB |
56.2 eC |
0.0 aA |
2.0 bB |
32.7 eC |
0.0 aA |
1.0 aA |
25.7 dB |
Sulfentrazone/diuron (245/490) |
0.0 aA |
15.5 cB |
44.5 dC |
0.0 aA |
12.5 dB |
28.2 dC |
0.0 aA |
3.7 bB |
26.2 dC |
Clomazone (900) |
0.0 aA |
2.5 bB |
5.5 bC |
0.0 aA |
2.7 bB |
2.0 bB |
0.0 aA |
1.0 aAB |
2.2 bB |
S-metolachlor (1.440) |
0.0 aA |
17.5 dB |
25.5 cC |
0.0 aA |
9.7 cB |
14.7 cC |
0.0 aA |
4.2 bB |
12.2 cC |
Non-treated control |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
0.0 aA |
V4: fourth trifoliolate. V6-V7:
sixth-seventh trifoliate. R1: beginning flowering - plants have at
least one flower on any node
ªRates at acid
equivalent (ae) for imazethapyr and at active ingredient (a.i.) for other
herbicides
Means followed by the same letter,
lowercase for herbicide and uppercase for application period, do not differ
from each other by Tukey's test at the 5% probability level
Table 6: Plant height (cm) of soybean under herbicide (g
ha-1)ª applied at sowing, and 7 and 14 days after sowing
(DAS)
Application period |
Trial 1 |
Trial 2 |
||||
|
Sowing |
7 DAS |
14 DAS |
Sowing |
7 DAS |
14 DAS |
114.4 A |
115.2 A |
91.9 B |
112.8 aA |
114.5 aA |
104.8 bcB |
|
Sulfentrazone/diuron (245/490) |
114.2 A |
114.9 A |
93.2 B |
111.4 aA |
118.2 aA |
97.2 cB |
Clomazone (900) |
113.7 A |
110.7 A |
113.5 A |
114.9 aA |
116.9 aA |
112.2 abA |
S-metolachlor (1.440) |
114.7 A |
111.5 A |
110.0 A |
115.0 aA |
113.1 aA |
113.8 aA |
Non-treated control |
114.1 A |
113.9 A |
112.2 A |
112.4 aA |
113.8 aA |
115.0 aA |
ªRates at acid
equivalent (ae) for imazethapyr, and at active ingredient (a.i.) for other
herbicides
Means followed by the same letter,
lowercase for herbicide and uppercase for application period, do not differ
from each other by Tukey's test at the 5% probability level
Table 7: Soybean yield (kg ha-1) under herbicide (g ha-1)ª
applied at sowing, and 7 and 14 days after sowing (DAS). Trial 1
Application period |
Sowing |
7 DAS |
14 DAS |
Imazethapyr/flumioxazin (100/50) |
4.173 A |
4.101 A |
3.869 A |
Sulfentrazone/diuron (245/490) |
4.042 AB |
4.303 A |
3.696 B |
Clomazone (900) |
4.332 A |
4.174 A |
4.048 A |
S-metolachlor (1.440) |
4.194 A |
4.119 A |
4.239 A |
Non-treated control |
4.239 A |
4.122 A |
4.159 A |
ªRates at acid
equivalent (ae) for imazethapyr, and at active ingredient (ai) for other
herbicides
Means followed by the same letter,
lowercase for herbicide and uppercase for application period, do not differ
from each other by Tukey's test at 5% probability level
Discussion
The injury to soybean plants caused by
herbicides is perceived by the changes they cause in the plant’s physiology,
which may eventually cause its death and yield reductions (Moscardi et al. 2012; Nandula et al. 2019). In the present study,
injury was not observed when herbicides were applied during sowing. The highest
phytotoxic potential was found for flumioxazin/imazethapyr and
sulfentrazone/diuron. Injury symptoms after herbicide application, in addition
to foliar lesions, can also be observed as a reduction in plant height. Plants
require light for growth and development and when the application of herbicides
results in changes in their size, they may suffer consequences in their
physiology, altering other parameters, such as yield (Arantes et al. 2015).
The application of sulfentrazone (200 or 300 g a.i. ha-1) one
day after soybean sowing caused mild leaf chlorosis, with a
reduction in symptoms 15 days after crop emergence (Osipe et al. 2014). In another study, sulfentrazone (200 g a.i. ha-1)
applied one day after sowing soybeans caused injury to soybeans (up to 26%) 15
days after application, even so without impact on crop yield (Dalazen et al. 2020). Sulfentrazone is commonly
applied in soybean pre-emergence either with an interval of days before sowing
or upon sowing. Reiling et al. (2006)
observed injury in soybeans due to the application of sulfentrazone 7 days
before sowing, at sowing or at the VE stage of soybeans. Symptoms
were up to 17%, generally more intense for later applications or in soils with
lower organic carbon content but without reductions in soybean yield. Our
results corroborate these for the application of sulfentrazone in the case of a
pre-mixture with diuron. The results regarding the application of diuron in
soybean post-emergence are even scarcer, which reinforces the relevance of the
present study.
Diuron is a photosystem II inhibitor, its translocation is very low or
null, causing symptoms of interveinal chlorosis and, depending on the dose, the
plant may recover or be taken to death. It has a slower action compared to
sulfentrazone (protoporphyrinogen oxidase – PPO inhibitor), characterized by
leaf chlorosis with reduced growth (Jr et
al. 2021). PPO-inhibiting herbicides applied directly to leaves may have
low selectivity (Green and Owen 2011). However, some crops can recover from
foliar symptoms (Silva et al. 2018; Jr
et al. 2021).
Other studies evaluating post-emergence or pre-emergence soybean
herbicides reported that flumioxazin and s-metolachlor can be applied on the
day of soybean sowing, and sulfentrazone should be applied at least fourteen
days before sowing to avoid damage to soybean plants (Gazola et al. 2021). While herbicides
s-metolachlor and imazethapyr caused 10 to 15% of injury and fomesafen or
fomesafen + imazethapyr caused 15 to 25% of injury in soybean for soybean
post-emergence application (Oliveira et
al. 2017).
The post-emergence application of s-metolachlor in different mixtures
at the V3–V4 soybean stage caused injury of up to 12% but
without negative impacts on the agronomic performance of the crop and with
efficiency in controlling weeds (Sarangi and Jhala 2019). The selectivity
demonstrated by s-metolachlor may be related to the plant metabolism rate,
however, this is not fully confirmed as observed in the present study.
The selectivity presented by clomazone in the soybean crop, however,
may be related to a set of secondary factors, such as hydroxylation, breakage
of the chain at the -N-CH2 radical, conjugation with metabolites,
consequently a more accentuated metabolism and a reduction in the translocation
to the trials of action (Jr et al.
2021). Recent studies evaluating the application of clomazone in soybean
post-emergence are scarce, which highlights the importance of the present
study.
The investigation of possible effects of pre-emergence herbicides on
soybeans is very important given the few studies in this subject. Ribeiro et al. (2021) observed a reduction in
the height of soybean plants (VC stage), for the application of
sulfentrazone in pre-emergence of soybeans, however, from V2 and
onwards, no further reductions were observed. In addition to sulfentrazone,
herbicides imazethapyr, chlorimuron, cloransulam, metribuzin, flumioxazin,
saflufenacil, acetochlor, s-metolachlor, dimethenamid-P and pyroxasulfone were
also tested and found to have no effects on growth, development and biological
nitrogen fixation of soybean plants.
Clomazone and s-metolachlor were
selective for soybean as pre-emergence at 7 and 14 DAS. Imazethapyr/flumioxazin
or sulfentrazone/diuron at 14 DAS caused significant injury to soybean
including reduced plant height and for sulfentrazone/diuron a reduction in
yield was found for application at 14 DAS compared to 7 DAS. The highest
phytotoxic potential was observed for the application at 14 DAS of
flumioxazin/imazethapyr and sulfentrazone/diuron with crop injury of up to
56.2%. Therefore, the recommendation for the application of these herbicides
during the initial post-emergence of soybeans should be considered with
caution. The use of pre-emergence herbicides is a great tool for weed
management. Nevertheless, the best herbicide alternative and dose must be
defined with criteria with the aim of not causing significant damage to
soybeans especially if they are applied after sowing.
Conclusion
The application of clomazone and s-metolachlor were selective for
soybean when applied as pre-emergence at 7 and 14 days after sowing (DAS). The
application of imazethapyr/flumioxazin or sulfentrazone/diuron at 14 DAS caused
significant injury to soybean. The application of sulfentrazone/diuron caused a
reduction in yield for application at 14 DAS compared to 7 DAS. The highest
phytotoxic potential was observed for the application of
flumioxazin/imazethapyr and sulfentrazone/diuron at 14 DAS but without yield
reduction. The application of
herbicides as pre-sowing at 7 and 14 DAS was selective for soybean except
sulfentrazone/diuron at 14 DAS which reduced soybean yield.
Acknowledgements
The authors are grateful for the support of the Federal University of Paraná
(UFPR) and the Supra Pesquisa team at UFPR.
Author Contributions
JRB, AJP and LPA planned the experiment. JRB, FCG, LGM, MF and ESP
conducted the experiment in the field. JRB and AJP interpreted the results,
JRB, AJPA and AFMS wrote the original version of the manuscript. AFMS
statistically analyzed the data. All authors contributed to the final editing
of the manuscript.
Conflict of Interest
All authors declare no conflict of interest.
Data Availability
Data presented in this study will be available on a fair request to the
corresponding author.
Ethics Approval
Not applicable in this manuscript.
References
Albrecht LP, AJP Albrecht, AFM Silva,
LM Silva, DC Neuberger, G Zanfrilli, VMS Antunes (2022). Sumatran fleabane (Conyza
sumatrensis [Retz.] E. Walker) control in soybean with combinations of
burndown and preemergence herbicides applied in the off-season. Arq Inst Biol 89:e00052022
Albrecht AJP, LP Albrecht, SNR Alves, AFM Silva, WDO Silva, JB
Lorenzetti, MTY Danilussi, AAM Barroso (2021). Pre-sowing
application of combinations of burndown and pre-emergent herbicides for Conyza
spp. control in soybean. Agron Colomb 39:121‒128
Arantes JGZ, J Constantin, RSO Jr, GBP Braz, HK Takano, A Gemelli, P Brugnera (2015). Selectivity of clomazone in chemical management of
weed in cotton LL® crop. Plant Danin 33:283‒293
Barroso AAM, G Dalazen, A Gonçalves-Netto, E Roncatto, MR Malardo, C
Markus, PJ Christoffoleti (2021). Controle de espécies resistentes a glifosato.
In: Matologia: Estudos Sobre Plantas
Daninhas, pp:392‒427. Barroso AAM, AT Murata (Eds). Fábrica da
Palavra, Jaboticabal, SP, Brazil
Belfry KD, C Shropshire, PH Sikkema
(2016). Identity-preserved soybean tolerance to protoporphyrinogen
oxidase-inhibiting herbicides. Weed
Technol 30:137‒147
Belfry KD, N Soltani, LR Brown, PH
Sikkema (2015). Tolerance of identity preserved soybean cultivars to
preemergence herbicides. Can J Plant Sci 95:719‒726
Carvalho SJP, M Nicolai, RR Ferreira, AVO Figueira, PJ Christoffoleti
(2009). Herbicide selectivity by differential metabolism: Considerations
for reducing crop damages. Sci Agric 66:136‒142
Chahal PS, ZA Ganie, AJ Jhala (2018).
Overlapping residual herbicides for control of photosystem (PS) II-and
4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibitor-resistant Palmer amaranth
(Amaranthus palmeri S. Watson) in glyphosate-resistant maize. Front
Plant Sci 8:2231
Dalazen G, TE Kaspary, C Markus, A
Pisoni, AM Jr (2020). Soybean tolerance to sulfentrazone and diclosulam in
sandy soil. Plant Danin 38:e020225717
Ferreira DF (2011). Sisvar: A computer statistical analysis system. Cienc
Agrotecnol 35:1039‒1042
Fornazza FGF, J Constantin, FG Machado, RSDO Jr, GDD Silva, FA Rios
(2018). Selectivity of pre-and post-emergence herbicides to
very-early maturing soybean cultivars. Comun Sci 9:649‒658
Gazola T, DM Gomes, D Belapart, MF Dias, CA Carbonari, ED Velini (2021).
Selectivity and residual weed control of pre-emergent
herbicides in soybean crop. Rev Ceres 68:219‒229
Green JM, MD Owen (2011).
Herbicide-resistant crops: Utilities and limitations for herbicide-resistant
weed management. J Agric Food Chem 59:5819‒5829
Hay MM, DE Shoup, DE Peterson (2019).
Herbicide options for control of palmer amaranth (Amaranthus palmeri)
and common waterhemp (Amaranthus rudis) in double-crop soybean. Weed Technol 33:106‒114
Jr RSO, DF Biffe, FG Machado, VFV Silva (2021). Mecanismos de ação de
herbicidas. In: Matologia: Estudos
Sobre Plantas Daninhas,
pp:170‒204. Barroso
AAM, AT Murata (Eds). Fábrica da Palavra, Jaboticabal, SP, Brazil
Kniss AR, EG Mosqueda, NC Lawrence, AT
Adjesiwor (2022). The cost of implementing effective herbicide mixtures for
resistance management. Adv Weed Sci 40:e0202200119
Moscardi F, AF Bueno, RCOF Bueno, A
Garcia (2012). Soybean response to different injury levels at early
developmental stages. Cienc Rur 42:389‒395
Nandula VK, DE Riechers, Y Ferhatoglu,
M Barrett, SO Duke, FE Dayan, R Ma (2019). Herbicide metabolism: crop selectivity,
bioactivation, weed resistance and regulation. Weed Sci 67:149‒175
Neto MEF, RA Pitelli, EAG Basile, PC
Timossi (2009). Selectivity of post-emergence herbicides applied on genetically
modified soybeans. Plant Danin 27:345‒352
Oliveira MC, D Feist, S Eskelsen, JE Scott, SZ Knezevic (2017). Weed control in soybean with preemergence‐and postemergence‐applied
herbicides. Crop Forage Turfgrass Manage 3:1‒7
Osipe JB, RSO Jr, J Constantin, DF Biffe, FA Rios, LHM Franchini, MA Raimondi (2014). Selectivity of combined applications of herbicides
in pre and post-emergence for the glyphosate tolerant soybean. Biosci J
30:623‒631
Reiling KL, FW Simmons, DE Riechers, LE
Steckel (2006). Application timing and soil factors affect sulfentrazone phytotoxicity
to two soybean (Glycine max (L.) Merr.) cultivars. Crop Prot 25:230‒234
Ribeiro VHV, LGS Maia, NJ Arneson, MC Oliveira, HW Read, JM Ané, R Werle (2021). Influence of PRE-emergence herbicides on soybean
development, root nodulation and symbiotic nitrogen fixation. Crop Prot
144:105576
Sarangi D, AJ Jhala (2019). Palmer
amaranth (Amaranthus palmeri) and velvetleaf (Abutilon theophrasti)
control in no-tillage conventional (non–genetically engineered) soybean using
overlapping residual herbicide programs. Weed Technol 33:95‒105
Silva AFM, AJP Albrecht, HRM Viana, BF
Giovanelli, GA Ghirardello, LRD Marco, LP Albrecht, RV Filho (2018).
Glyphosate, isolated or in associations, at agronomic performance and seed
quality of the RR® 2 soybean. Arq Inst Biol 85:e0732017
Tukey JW (1949). Comparing individual
means in the analysis of variance. Biometrics 5:99‒114
Velini ED, R Osipe, DLP Gazziero (1995). Procedimentos Para
Instalação, Avaliação e Análise de Experimentos Com Herbicidas. SBCPD, Londrina, PR, Brazil