Introduction
Rising food demand for the
growing global population is a big challenge for scientists and producers to produce
more food ensuring its security in foreseeable future. Wheat (Triticum
aestivum L.) is the world’s most widely grown cereal crop, thanks to its
adaptability to a variety of climates (Curtis 2021). It
is the major staple food in Pakistan and is cultivated on a large scale in the
country. The share of wheat to value addition in agriculture and Gross
Domestic Product (GDP) of Pakistan is 8.7 and 1.7%, respectively (GOP 2020).
There are many abiotic and
biotic factors that affect wheat yield (Tester and Langridge 2010). Among these
yield limiting factors, weeds remain always a major problem. Despite many
advances in weed management technology, crop growers still face significant
yield losses due to weeds (Harker and O'donovan 2013; Shahzad et al.
2016) as these can reduce the yield by utilizing the sunlight, water, space and
fertilizer. It has been estimated that weeds can cause 23% wheat yield
reduction worldwide (Gaba et al. 2016). The major
noxious weeds of wheat are Phalaris minor (littleseed canarygrass), Lathyrus
aphaca (yellow pea), Medicago
polymorpha (bur clover), Avena fatua (wild oat), Melilotus
indica (sweet clover), Polypogon fugax (rabbitsfoot grass), Chenopodium
album (white goosefoot) and Cirsium arvense (creeping thistle)
(Waheed et al. 2009) and their severe
infestation causes huge yield loss (Hamid et
al. 1998). However, among these weeds only littleseed canarygrass can exert
a yield decline up to 80% (Singh et al.
2012), wild oat up to 40% (Jäck et al. 2017), Poa annua (annual
bluegrass) up to 76% and Coronopus
didymus (swinecress) up to
75% (Siddiqui et al. 2010).
Therefore, owing to huge losses imposed by weeds, several on-farm techniques to
control them are adopted, however, each technique has both merits and demerits
depending upon the prevailing weeds flora, soil type, and cropping system. The
methods mainly involve the use of weedicides, tillage operations, manual
weeding, hoeing, higher seeding density, sowing methods, intercropping, mixed
cropping, mulching, cultivation of weed competitive varieties, and use of
fertilizer practices (Riaz et al. 2006).
Manual weeding (MW) is one of the old-fashioned
eradication techniques in many developing countries like Pakistan, India,
China, Nepal and Bangladesh. However, recent shortage of agricultural labor, a
strenuous and inefficient job to control weeds by MW, this method is becoming
less practical (Hossain 2015).
The above mentioned constraints have compelled the
researchers to find out the other alternative weed control measures that are
most effective and economically viable. Chemical weed control using herbicides
is quite a proficient and economical way in controlling weeds (Zargar et al.
2019). Herbicidal weed control offers a remarkable reduction in soil erosion,
greenhouse gas emissions, fuel consumption and nutrient run-off and also
conserves water compared to other soil disturbance weed control techniques e.g.,
tillage, harrowing, etc. (Hossain
2015).
Herbicides have the potentiality to reduce weeding costs
significantly; however, herbicide resistance has emerged as a challenging issue
with particular chemicals and weed species (Walsh and Powles 2014). The
International Survey of Herbicide-Resistant Weeds (www.weed-science.org)
reveals 388 exceptional cases (biotype × site of action) of chemical-resistant
weeds worldwide, with 210 species. Weeds have already shown resistance to 21
out of 25 known herbicide sites of action and to 152 herbicide chemistries
(Heap 2019). The resistance against ALS inhibitors is the most common (126
species), followed by triazines (69 resistant species) and ACCase inhibitors
(42 resistant species). Repeated application of the same group of the herbicide
over time forced the resistance development mechanisms in weeds. The large area
having the sole application of glyphosate has evolved weed resistance to
glyphosate (Heap 2014). Littleseed canarygrass, the most problematic
weed of wheat production system including Pakistan, has evolved resistance to
fenoxaprop-p-ethyl and this is the first ever case seen for herbicide-resistant
weed in Pakistan (Abbas et al. 2016). It was reported that among eight
biotypes of littleseed canarygrass, four were resistant to
fenoxaprop-p-ethyl even at its double dose than the recommended. The resistance
development was due to the repeated use of this chemical over more than fifteen
years in Pakistan (Abbas et al. 2016). In another field survey study in
Pakistan, farmers reported that they were unable to control mainly littleseed
canarygrass followed by wild oat and toothed dock through chemicals.
These weeds might have developed herbicide resistance to repetitive use of
chemical weed control (Hashim et al. 2019).
Selective herbicides are used to control broad and
narrow leaved weeds in wheat crop (Ahmed et al. 2020). Herbicides
available in the Pakistani market have a different mode of action.
Tribenuron-methyl, Fluroxypyr, iodosulfuron methyl, mesosulfuron-methyl and
iodosulfuron-methyl sodium are selective herbicides that are used for
controlling broad leaved weeds in wheat. Fluroxypyr and aminopyralid belong to
pyridine-carboxylic acid family and they control the weeds by disrupting their
cells growth and division in newly forming leaves leading to malformed growth
and tumors. Tribenuron-methyl, metsulfuron methyl, mesosulfuron methyl and
iodosulfuron methyl belong to sulfonylurea family and inhibit the normal
functioning of acetolactate synthase enzyme which is important for protein
synthesis. Fenoxaprop-p-ethyl belongs to the family aryloxyphenoxy-propionate
and pinoxaden belongs to the family phenylpyrazoline. Both these herbicides
cause inhibition of acetyl CoA carboxylase (ACCase) enzyme. Carfentrazone-ethyl
belongs to the family triazolinone which causes inhibition of
protoporphyrinogen oxidase (PPO) enzyme.
Considering the issue of herbicide resistance, it is
urgent to determine the efficacy of different herbicides or herbicides
combinations to manage complex weed flora of wheat without depending on a
single group for a long time. Alternative herbicides with a different mode of
actions are the best options to control resistant weed species as well as to
prevent resistance weed evolution. Therefore, the present study was planned to
find out the most suitable and economical herbicides or herbicides combinations
that can control both broad and narrow leaved weeds effectively.
Materials and
Methods
Experimental
site
The study was conducted at the experimental farm of Rice
Research Institute, Kala Shah Kaku, Punjab, Pakistan (31°43'18.7"N
74°15'59.8"E) during the rabi season 2017–2018 and 2018–2019. The
pre-sowing soil analysis results of
experimental field are given in Table 1.
Field preparation and sowing
The field was prepared by two ploughings with disc
plough then two cultivations with cultivator followed by two planking. Wheat
cultivar Galaxy was sown after land preparation with
rabi drill seeder in 20 cm apart rows at a seed rate of 125 kg ha-1.
Sowing was performed on 16th and 13th of November in
2017–2018 and 2018–2019, respectively.
Table 1: Physicochemical properties
of experimental site
|
Parameters |
Soil depth |
|
|
0-6 inch |
6-12 inch |
|
|
Texture |
Clay loam |
Clay loam |
|
Organic
matter (%) |
0.41 |
0.28 |
|
Soil pH |
8.35 |
8.10 |
|
EC (dS m-1) |
1.39 |
0.95 |
|
SAR (m mol
L-1)1/2 |
7.27 |
7.16 |
|
Saturation
(%) |
44.00 |
34.00 |
|
Nitrogen
(%) |
0.53 |
0.29 |
|
Available P
(mg kg-1) |
5.60 |
5.30 |
|
Available K
(mg kg-1) |
90.00 |
69.00 |
Where,
EC = Electrical Conductivity, SAR = Sodium Adsorption Ratio, P = Phosphorus, K =
Potassium
Experimental design, treatments and their application
The experiment was laid out in Randomized Complete Block
Design with three replications having 72 m2 (3.60 m × 20 m) plot
size. The experiment consisted of a total of 18 treatments (16 were
herbicide-based weed management, one hand weeding and one weedy check) and
details are given in Table 2. Herbicides were sprayed using a knapsack hand
sprayer after first irrigation at 45 days after sowing (DAS) in a moist soil
using water solution at the rate of 300 L ha-1 determined after
calibration. The hand weedings were done manually, and a weedy check plot was
left un-weeded for the whole crop season.
Fertilizer Management
Phosphorus (diammonium phosphate) and potassium (sulfate
of potash) fertilizers were applied at the rate of 110 and 60 kg ha-1,
respectively, at the time of field preparation. Nitrogen (urea) at the rate of
130 kg ha-1 was applied in two splits i.e., 1/2 N was applied
at sowing and the remaining was immediately after first irrigation.
Data Collection
Naturally occurring weeds in each plot were counted from
two randomly selected places by using a quadrate (40 cm by 40 cm) at 25 days
after herbicide spray. The weed plants were uprooted from the ground surface,
cleaned and washed the roots well, and counted species-wise. The wheat plants
were also uprooted from the same area and tillers were counted. The wheat and
weed species samples were placed separately in a brown envelope and oven dried
at 70°C for constant biomass determination. The crop was harvested at maturity
and the grain and straw yield was measured from the center of each plot on an
area of 5 m2. The grain yield was determined at 12% moisture
content. At maturity plant height was measured of 10 randomly selected plants.
The number of spike m-2, number of spikelets spike-1 were
counted and 1000-grain weight was also measured.
Statistical analysis
The data for both the years were subjected to analysis
of variance (ANOVA) using a statistical software
(STAR 2015). The least significance difference (LSD) test at P ≤ 0.05 was used to compare the
treatment means. For all the parameters collected, two years combined model was
run and found most of the parameters were significant, therefore, data were
presented year wise (STAR 2015).
Results
Efficacy of
different weed control treatments (at 25 days after spraying of herbicide) on
weed density and biomass of most dominant weed species
Littleseed
canarygrass: The weed control method mesosulfuron-methyl +
iodosulfuron-methyl-sodium and pinoxaden sole or in combination with other
post-emergence herbicides reduced littleseed canarygrass density above 90% during both years of study (Table 3). However,
the sole application of fluroxypyr meptyle and carfentrazone-ethyl and
tribenuron methyl + metsulfuron methyl were not so effective against this weed.
The first two chemicals reduced the density only from 0–6% while for the later
it was 4% more as compared to control (Table 3). A similar density of the weed
was recorded from the weed control treatments carfentrazone-ethyl, tribenuron
methyl + metsulfuron methyl, fluroxypyr meptyle, and fluroxypyr meptyle + amino
pyralid.
Similarly, fluroxypyr meptyle, tribenuron methyl +
metsulfuron methyl, carfentrazone-ethyl and fluroxypyr meptyle + amino pyralid
had a little impact on the biomass of littleseed canarygrass during both years,
however, mesosulfuron-methyl + iodosulfuron-methyl-sodium and pinoxaden applied
individually or in combination with other herbicides reduced the biomass of the
weed more than 90% as compared with control (Table 3). Fenoxaprop-p-ethyl also
reduced the density and biomass of littleseed canarygrass but observed lower
efficacy than mesosulfuron-methyl + iodosulfuron-methyl-sodium, and pinoxaden
(Table 3).
Yellow pea
Compared with
season long weedy plots (control), all weed control treatments except the sole
application of pinoxaden and fenoxaprop-p-ethyl significantly reduced yellow
pea density by 62–96% and
61–100% in 2017–2018 and 2018–2019, respectively (Table 4). The sole application of
fenoxaprop-p-ethyl was less effective against yellow pea and reduced
weed density only 35% while pinoxaden herbicide found ineffective against this
weed in both years (Table 4).
Weed biomass followed a similar trend to weed density in
both years and weed control treatments fluroxypyr meptyle, fluroxypyr meptyle +
amino pyralid, carfentrazone-ethyl, mesosulfuron-methyl +
iodosulfuron-methyl-sodium, and tribenuron methyl + metsulfuron methyl
effectively reduced the biomass of this weed, while herbicides pinoxaden and
fenoxaprop-p-ethyl failed to reduce the biomass of this weed as compared to
weedy plots (Table 4).
Bur clover
Table 2: Experimental treatments along
with chemical composition and doses of different herbicides
|
Trade Name |
Active ingredient (a.i.)
* |
Dose ha-1 |
|
Allymax 66.7 WG |
Tribenuron methyl + metsulfuron methyl
(Tm + Mtm) |
24
g |
|
Axial
50 EC |
Pinoxaden (with cloquintocet-mexyl
safener) (Pd) |
815.10
mL with safenar 500 mL |
|
Atlantis
3.6 WG |
Mesosulfuron-methyl + iodosulfuron-methyl-sodium
(Msm + Im) |
395.20
g |
|
Puma
super 69 EW |
Fenoxaprop-p-ethyl
(Fn) |
1235
mL |
|
Starane-M 50 EC |
Fluroxypyr meptyle (Flm) |
741
mL |
|
Cleanwave |
Fluroxypyr meptyle + amino pyralid (Flm +Ap) |
790.40
mL |
|
Aim
40 DF |
Carfentrazone-ethyl (Ce) |
49.40
g |
|
Allymax + Axial |
Tribenuron methyl + metsulfuron methyl
plus pinoxaden (Tm + Mtm
plus Pd) |
24
g + 815.10 mL |
|
Allymax + Atlantis |
Tribenuron methyl + metsulfuron methyl
plus Mesosulfuron-methyl + iodosulfuron-methyl-sodium
(Tm + Mtm plus Msm + Im) |
24
g + 395.20 g |
|
Allymax + Puma super |
Tribenuron methyl + metsulfuron methyl
plus Fenoxaprop-p-ethyl (Tm + Mtm plus Fn) |
24
g + 1235 mL |
|
Axial + Starane-M |
Pinoxaden plus Fluroxypyr meptyle (Pd plus Flm) |
815.10
mL + 741 mL |
|
Axial
+ Cleanwave |
Pinoxaden plus Fluroxypyr meptyle + amino pyralid (Pd
plus Flm + Ap) |
815.10
mL + 790.40 mL |
|
Atlantis
+ Starane-M |
Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle (Msm + Im plus Flm) |
395.20
g + 741 mL |
|
Atlantis
+ Cleanwave |
Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle +
amino pyralid (Msm + Im plus Flm + Ap) |
395.20
g + 790.40 mL |
|
Puma
super + Starane-M |
Fenoxaprop-p-ethyl
plus Fluroxypyr meptyle (Fn plus Flm) |
1235
mL + 741 mL |
|
Puma
super + Cleanwave |
Fenoxaprop-p-ethyl
plus Fluroxypyr meptyle +
amino pyralid (Fn plus Flm + Ap) |
1235
mL + 790.40 mL |
|
Hand
weeding (Hw) |
||
|
Control
(Ct) |
|
|
*within
the parentheses is the short treatment name used in the manuscript
Table 3: Effect of
different weed control methods on weed density and dry weight of littleseed canarygrass during
2017–2018 and 2018–2019
|
Treatments |
2017–2018 |
2018–2019 at 25 days after spraying of herbicide |
||||||
|
Number m–2 |
% decrease
(–) or increase (+) over control |
Dry Weight (g m–2) |
% decrease
(–) or increase (+) over control |
Number m–2 |
% decrease
(–) or increase (+) over control |
Dry Weight (g m–2) |
% decrease
(–) or increase (+) over control |
|
|
Tm
+ Mtm |
453.12 |
+3.94 |
38.60 |
+6.78 |
317.19 |
–19.76 |
7.54 |
–81.50 |
|
Pd |
45.31 |
–89.61 |
1.78 |
–95.08 |
35.94 |
–90.91 |
5.13 |
–87.41 |
|
Msm + Im |
20.00 |
–95.41 |
1.10 |
–96.96 |
28.12 |
–92.89 |
1.73 |
–95.76 |
|
Fn |
100.69 |
–76.90 |
8.65 |
–76.07 |
72.19 |
–81.74 |
10.58 |
–74.04 |
|
Flm |
435.94 |
0.00 |
37.60 |
+4.01 |
334.38 |
–15.41 |
33.56 |
–17.66 |
|
Flm + Ap |
321.88 |
–26.16 |
30.30 |
–16.18 |
220.31 |
–44.27 |
29.31 |
–28.09 |
|
Ce |
406.25 |
–6.81 |
33.39 |
–7.63 |
126.56 |
–67.98 |
12.31 |
–69.80 |
|
Tm
+ Mtm plus Pd |
18.25 |
–95.81 |
2.19 |
–93.94 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Tm
+ Mtm plus Msm + Im |
20.56 |
–95.28 |
2.31 |
–93.61 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Tm
+ Mtm plus Fn |
39.06 |
–91.04 |
2.43 |
–93.28 |
46.88 |
–88.14 |
10.25 |
–74.85 |
|
Pd
plus Flm |
26.88 |
–93.83 |
1.98 |
–94.52 |
25.00 |
–93.68 |
2.35 |
–94.23 |
|
Pd
plus Flm + Ap |
20.31 |
–95.34 |
1.74 |
–95.19 |
7.81 |
–98.02 |
0.63 |
–98.45 |
|
Msm + Im plus Flm |
37.19 |
–91.47 |
2.31 |
–93.61 |
28.12 |
–92.89 |
1.66 |
–95.93 |
|
Msm + Im plus Flm + Ap |
46.88 |
–89.25 |
2.81 |
–92.23 |
9.38 |
–97.63 |
1.15 |
–97.18 |
|
Fn plus Flm |
150.00 |
–65.59 |
14.32 |
–60.39 |
130.00 |
–67.11 |
12.56 |
–69.19 |
|
Fn plus Flm + Ap |
23.44 |
–94.62 |
0.97 |
–97.32 |
35.94 |
–90.91 |
2.55 |
–93.74 |
|
Hw |
35.62 |
–91.83 |
5.29 |
–85.37 |
25.00 |
–93.68 |
5.54 |
–86.41 |
|
Ct |
435.94 |
0.00 |
36.15 |
0.00 |
395.31 |
0.00 |
40.76 |
0.00 |
|
LSD (P ≤ 0.05) |
168.78 |
– |
12.88 |
– |
85.04 |
– |
10.78 |
– |
Where,
Tm + Mtm=Tribenuron methyl
+ metsulfuron methyl; Pd = Pinoxaden
(with cloquintocet-mexyl safener); Msm + Im=Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; Fn
= Fenoxaprop-p-ethyl; Flm = Fluroxypyr
meptyle; Flm + Ap=Fluroxypyr meptyle + amino pyralid; Ce = Carfentrazone-ethyl;
Tm + Mtm plus Pd = Tribenuron
methyl + metsulfuron methyl plus pinoxaden;
Tm + Mtm plus Msm + Im = Tribenuron methyl + metsulfuron methyl plus Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; (Tm + Mtm plus Fn = Tribenuron
methyl + metsulfuron methyl plus Fenoxaprop-p-ethyl;
Pd plus Flm = Pinoxaden
plus Fluroxypyr meptyle; Pd
plus Flm + Ap = Pinoxaden
plus Fluroxypyr meptyle +
amino pyralid; Msm + Im plus Flm = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium plus Fluroxypyr
meptyle; Msm + Im plus Flm + Ap = Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle +
amino pyralid; Fn plus Flm = Fenoxaprop-p-ethyl plus Fluroxypyr
meptyle; Fn plus Flm + Ap =
Fenoxaprop-p-ethyl plus Fluroxypyr meptyle + amino pyralid; Hw = hand weeding; Ct = Control
Relative to
the control plots, the plots applied with fluroxypyr meptyle, fluroxypyr meptyle + amino pyralid, mesosulfuron-methyl +
iodosulfuron-methyl-sodium, and carfentrazone-ethyl and their combinations with
other post-emergence herbicides provided excellent control of bur clover and
reduced density by 82–100% in 2017–2018 and 87–100% in 2018–2019 (Table 5).
While, lower weed control percentage was observed for the weed control method
tribenuron methyl + metsulfuron methyl or its combination with pinoxaden,
pinoxaden alone and fenoxaprop-p-ethyl. The weed control methods
fenoxaprop-p-ethyl and pinoxaden produced no impact on this weed and had
similar weed density and biomass to control (Table 5).
Number of wheat tillers m-2 and dry weight at
70 DAS
Table 4: Effect of
different weed control methods on weed density and dry weight of yellow pea during 2017–2018 and 2018–2019
|
Treatments |
2017–2018 |
2018–2019 at 25 days after spraying of herbicide |
||||||
|
Number m–2 |
% decrease
(–) or increase (+) over control |
Dry Weight (g m–2) |
% decrease
(–) or increase (+) over control |
Number m–2 |
% decrease
(–) or increase (+) over control |
Dry Weight (g m–2) |
% decrease
(–) or increase (+) over control |
|
|
Tm
+ Mtm |
13.44 |
–74.70 |
0.57 |
–35.23 |
14.06 |
–60.53 |
0.85 |
–11.46 |
|
Pd |
90.62 |
+70.59 |
4.56 |
+418.18 |
34.06 |
–4.38 |
1.73 |
+80.21 |
|
Msm + Im |
21.25 |
–60.00 |
1.20 |
+36.36 |
8.00 |
–77.54 |
0.26 |
–72.92 |
|
Fn |
34.38 |
–35.28 |
2.38 |
+170.45 |
40.62 |
14.04 |
2.81 |
192.71 |
|
Flm |
5.88 |
–88.93 |
0.37 |
–57.95 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Flm + Ap |
39.06 |
–26.47 |
0.69 |
–21.59 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Ce |
28.12 |
–47.06 |
0.76 |
–13.64 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Tm
+ Mtm plus Pd |
10.06 |
–81.06 |
0.23 |
–73.86 |
7.81 |
–78.07 |
0.28 |
–70.83 |
|
Tm
+ Mtm plus Msm + Im |
4.38 |
–91.75 |
1.28 |
+45.45 |
4.69 |
–86.83 |
0.26 |
–72.92 |
|
Tm
+ Mtm plus Fn |
18.12 |
–65.89 |
1.37 |
+55.68 |
10.94 |
–69.29 |
0.16 |
–83.33 |
|
Pd
plus Flm |
12.5 |
–76.47 |
0.31 |
–64.77 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Pd
plus Flm + Ap |
12.5 |
–76.47 |
0.17 |
–80.68 |
5.00 |
–85.96 |
0.00 |
–100.00 |
|
Msm + Im plus Flm |
20.31 |
–61.77 |
0.34 |
–61.36 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Msm + Im plus Flm + Ap |
6.25 |
–88.23 |
0.14 |
–84.09 |
4.00 |
–88.77 |
0.14 |
–85.42 |
|
Fn plus Flm |
2.00 |
–96.23 |
0.54 |
–38.64 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Fn plus Flm + Ap |
9.38 |
–82.34 |
0.84 |
–4.55 |
3.00 |
–91.58 |
0.13 |
–86.46 |
|
Hw |
21.88 |
–58.81 |
0.57 |
–35.23 |
2.00 |
–94.39 |
0.11 |
–88.54 |
|
Ct |
53.12 |
0.00 |
0.88 |
0.00 |
35.62 |
0.00 |
0.96 |
0.00 |
|
LSD (P ≤ 0.05) |
25.43 |
– |
1.21 |
– |
10.44 |
– |
0.62 |
– |
Where,
Tm + Mtm = Tribenuron
methyl + metsulfuron methyl; Pd = Pinoxaden
(with cloquintocet-mexyl safener); Msm + Im = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; Fn
= Fenoxaprop-p-ethyl; Flm = Fluroxypyr
meptyle; Flm + Ap = Fluroxypyr meptyle + amino pyralid; Ce = Carfentrazone-ethyl;
Tm + Mtm plus Pd = Tribenuron
methyl + metsulfuron methyl plus pinoxaden;
Tm + Mtm plus Msm + Im = Tribenuron methyl + metsulfuron methyl plus Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; (Tm + Mtm plus Fn = Tribenuron
methyl + metsulfuron methyl plus Fenoxaprop-p-ethyl;
Pd plus Flm = Pinoxaden
plus Fluroxypyr meptyle; Pd
plus Flm + Ap = Pinoxaden
plus Fluroxypyr meptyle +
amino pyralid; Msm + Im plus Flm = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium plus Fluroxypyr
meptyle; Msm + Im plus Flm + Ap = Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle +
amino pyralid; Fn plus Flm = Fenoxaprop-p-ethyl plus Fluroxypyr
meptyle; Fn plus Flm + Ap = Fenoxaprop-p-ethyl
plus Fluroxypyr meptyle +
amino pyralid; Hw = hand
weeding; Ct = Control
Table 5: Effect of
different weed control methods on weed density and dry weight of Bur clover
during 2017–2018 and 2018–2019
|
Treatments |
2017–2018 |
2018–2019 at 25 days after spraying of herbicide |
||||||
|
Number m–2 |
% decrease
(–) or increase (+) over control |
Dry Weight (g m–2) |
% decrease
(–) or increase (+) over control |
Number m–2 |
% decrease
(–) or increase (+) over control |
Dry Weight (g m–2) |
% decrease
(–) or increase (+) over control |
|
|
Tm
+ Mtm |
29.69 |
+26.66 |
0.92 |
+35.29 |
4.69 |
–81.00 |
0.15 |
0.00 |
|
Pd |
32.81 |
+39.97 |
1.74 |
+155.88 |
20.31 |
–17.74 |
1.72 |
+1046.67 |
|
Msm + Im |
6.25 |
–73.34 |
0.22 |
–67.65 |
3.00 |
–87.85 |
0.15 |
+0.00 |
|
Fn |
34.38 |
+46.67 |
0.75 |
+10.29 |
23.44 |
–5.06 |
1.14 |
+660.00 |
|
Flm |
0.00 |
–100.00 |
0.00 |
–100.00 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Flm + Ap |
0.00 |
–100.00 |
0.00 |
–100.00 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Ce |
4.69 |
–79.99 |
0.19 |
–72.06 |
3.12 |
–87.36 |
0.22 |
+46.67 |
|
Tm
+ Mtm plus Pd |
0.00 |
–100.00 |
0.00 |
–100.00 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Tm
+ Mtm plus Msm + Im |
7.81 |
–66.68 |
0.39 |
–42.65 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Tm
+ Mtm plus Fn |
3.12 |
–86.69 |
0.05 |
–92.65 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Pd
plus Flm |
14.06 |
–40.02 |
0.84 |
+23.53 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Pd
plus Flm + Ap |
9.38 |
–59.98 |
0.11 |
–83.82 |
3.00 |
–87.85 |
0.11 |
–26.67 |
|
Msm + Im plus Flm |
6.25 |
–73.34 |
0.23 |
–66.18 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Msm + Im plus Flm + Ap |
6.25 |
–73.34 |
0.26 |
–61.76 |
3.00 |
–87.85 |
0.10 |
–33.33 |
|
Fn plus Flm |
4.00 |
–82.94 |
0.72 |
+5.88 |
3.00 |
–87.85 |
0.09 |
–40.00 |
|
Fn plus Flm + Ap |
0.00 |
–100.00 |
0.00 |
–100.00 |
0.00 |
–100.00 |
0.00 |
–100.00 |
|
Hw |
3.12 |
–86.69 |
0.18 |
–73.53 |
3.00 |
–87.85 |
0.07 |
–53.33 |
|
Ct |
23.44 |
0.00 |
0.68 |
0.00 |
24.69 |
0.00 |
0.15 |
0.00 |
|
LSD (P ≤ 0.05) |
15.50 |
– |
0.79 |
– |
3.97 |
– |
0.32 |
– |
Where,
Tm + Mtm = Tribenuron
methyl + metsulfuron methyl; Pd = Pinoxaden
(with cloquintocet-mexyl safener); Msm + Im=Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; Fn
= Fenoxaprop-p-ethyl; Flm = Fluroxypyr
meptyle; Flm + Ap = Fluroxypyr meptyle + amino pyralid; Ce = Carfentrazone-ethyl;
Tm + Mtm plus Pd = Tribenuron
methyl + metsulfuron methyl plus pinoxaden;
Tm + Mtm plus Msm + Im = Tribenuron methyl + metsulfuron methyl plus Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; (Tm + Mtm plus Fn = Tribenuron
methyl + metsulfuron methyl plus Fenoxaprop-p-ethyl;
Pd plus Flm = Pinoxaden
plus Fluroxypyr meptyle; Pd
plus Flm + Ap = Pinoxaden
plus Fluroxypyr meptyle +
amino pyralid; Msm + Im plus Flm = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium plus Fluroxypyr
meptyle; Msm + Im plus Flm + Ap = Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle +
amino pyralid; Fn plus Flm = Fenoxaprop-p-ethyl plus Fluroxypyr
meptyle; Fn plus Flm + Ap = Fenoxaprop-p-ethyl
plus Fluroxypyr meptyle +
amino pyralid; Hw = hand
weeding; Ct = Control
All the weed control treatments had a significant impact of total tiller
density m-2 in both years and increased tiller density by 72–168% and 33–220% in 2017–2018 and 2018–2019, respectively as compared to weedy check
plots (Table 6). The highest tiller density was recorded with
mesosulfuron-methyl + iodosulfuron-methyl-sodium (460 tiller m-2) in
2017–2018 and
mesosulfuron-methyl + iodosulfuron-methyl-sodium plus fluroxypyr meptyle +
amino pyralid (591 tiller m-2) in 2018–2019 as compared to weedy check plots (Table
6). Similarly, all the weed control treatments either sole or in combination
increased the total wheat biomass insignificantly in both years. All the
treatments increased the wheat biomass by 25–90% and 20–95% in first and second
year, respectively. Maximum biomass was achieved in hand weeded plots in 2017–18 and in plots where mesosulfuron-methyl +
iodosulfuron-methyl-sodium was applied and it was followed by hand weeded plots
(Table 6).
Total number of weeds m-2 and total biomass
at 70 DAS
Table 6: Effect of
different weed control methods on wheat tiller density and wheat tiller dry
weight during 2017–2018 and 2018–2019
|
Treatments |
2017–2018 |
2018–2019 |
||||||
|
Number of tillers m–2 |
% increase
over control |
Dry weight (g m–2) |
% increase
over control |
Number of tillers m–2 |
% increase
over control |
Dry weight (g m–2) |
% increase
over control |
|
|
Tm+Mtm |
305.00 |
77.45 |
1018.75 |
39.32 |
375.31 |
103.55 |
1115.62 |
55.55 |
|
Pd |
354.69 |
106.36 |
1179.69 |
61.33 |
389.06 |
111.01 |
1235.94 |
72.33 |
|
Msm+Im |
460.oo |
167.63 |
1078.12 |
47.44 |
507.81 |
175.41 |
1398.44 |
94.99 |
|
Fn |
398.44 |
131.81 |
1051.56 |
43.80 |
354.69 |
92.37 |
1123.44 |
56.64 |
|
Flm |
295.31 |
71.81 |
915.62 |
25.21 |
245.3 |
33.04 |
862.50 |
20.26 |
|
Flm+Ap |
350.00 |
103.63 |
980.31 |
34.06 |
256.25 |
38.98 |
916.50 |
27.79 |
|
Ce |
290.62 |
69.08 |
934.38 |
27.78 |
368.75 |
99.99 |
959.38 |
33.77 |
|
Tm+Mtm plus Pd |
432.81 |
151.81 |
1309.38 |
79.06 |
421.88 |
128.81 |
1309.38 |
82.57 |
|
Tm+Mtm plus Msm+Im |
396.88 |
130.91 |
1153.12 |
57.69 |
415.62 |
125.41 |
1212.50 |
69.06 |
|
Tm
+ Mtm plus Fn |
354.69 |
106.36 |
1175.00 |
60.68 |
418.75 |
127.11 |
1176.56 |
64.05 |
|
Pd
plus Flm |
325.00 |
89.09 |
1215.62 |
66.24 |
354.69 |
92.37 |
1267.19 |
76.69 |
|
Pd
plus Flm+Ap |
331.25 |
92.72 |
1154.69 |
57.91 |
410.94 |
122.88 |
1321.88 |
84.31 |
|
Msm+Im plus Flm |
404.69 |
135.45 |
1218.75 |
66.67 |
515.62 |
179.65 |
1342.19 |
87.15 |
|
Msm+Im plus Flm+Ap |
442.19 |
157.27 |
1140.62 |
55.98 |
590.62 |
220.33 |
1278.12 |
78.21 |
|
Fn plus Flm |
368.75 |
114.54 |
1139.06 |
55.77 |
303.12 |
64.40 |
1139.06 |
58.82 |
|
Fn plus Flm+Ap |
442.19 |
157.27 |
1256.25 |
71.79 |
468.75 |
154.23 |
1270.31 |
77.12 |
|
Hw |
382.81 |
122.72 |
1382.81 |
89.10 |
504.69 |
173.72 |
1364.06 |
90.20 |
|
Ct |
171.88 |
0.00 |
731.25 |
0.00 |
375.31 |
103.55 |
717.19 |
0.00 |
|
LSD (P≤ 0.05) |
80.72 |
– |
144.88 |
– |
108.70 |
– |
155.33 |
– |
Where
Tm+Mtm=Tribenuron methyl + metsulfuron methyl; Pd=Pinoxaden
(with cloquintocet-mexyl safener); Msm+Im=Mesosulfuron-methyl + iodosulfuron-methyl-sodium; Fn=Fenoxaprop-p-ethyl;
Flm=Fluroxypyr meptyle; Flm+Ap=Fluroxypyr meptyle + amino pyralid; Ce=Carfentrazone-ethyl; Tm+Mtm plus Pd=Tribenuron methyl
+ metsulfuron methyl plus pinoxaden;
Tm+Mtm plus Msm+Im=Tribenuron methyl + metsulfuron
methyl plus Mesosulfuron-methyl + iodosulfuron-methyl-sodium;
(Tm + Mtm plus Fn=Tribenuron methyl + metsulfuron
methyl plus Fenoxaprop-p-ethyl; Pd plus Flm=Pinoxaden plus Fluroxypyr meptyle; Pd plus Flm+Ap=Pinoxaden plus Fluroxypyr meptyle + amino pyralid; Msm+Im plus Flm=Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle; Msm+Im plus Flm+Ap=Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle +
amino pyralid; Fn plus Flm= Fenoxaprop-p-ethyl plus Fluroxypyr
meptyle; Fn plus Flm+Ap=
Fenoxaprop-p-ethyl plus Fluroxypyr meptyle + amino pyralid; Hw=hand weeding; Ct=Control
Table 7: Effect of
different weed control methods on total weed density and total dry weight
during 2017–2018 and 2018–2019
|
Treatments |
2017–2018 |
2018–2019 |
||||||
|
Number m–2 |
% decrease
(–) or increase (+) over control |
Dry weight (g m–2) |
% decrease
(–) or increase (+) over control |
Number m–2 |
% decrease
(–) or increase (+) over control |
Dry weight (g m–2) |
% decrease
(–) or increase (+) over control |
|
|
Tm+Mtm |
496.25 |
–3.17 |
40.09 |
+6.31 |
335.94 |
–26.27 |
8.58 |
–79.51 |
|
Pd |
168.74 |
–67.08 |
8.08 |
–78.57 |
90.31 |
–80.18 |
2.14 |
–94.89 |
|
Msm+Im |
47.50 |
–90.73 |
2.52 |
–93.32 |
39.12 |
–91.41 |
14.53 |
–65.30 |
|
Fn |
169.45 |
–66.94 |
11.78 |
–68.76 |
136.25 |
–70.10 |
33.56 |
–19.85 |
|
Flm |
441.82 |
–13.79 |
37.97 |
+0.69 |
334.38 |
–26.61 |
29.31 |
–30.00 |
|
Flm+Ap |
360.94 |
–29.57 |
30.99 |
–17.82 |
220.31 |
–51.65 |
12.53 |
–70.07 |
|
Ce |
439.06 |
–14.33 |
34.34 |
–8.94 |
129.68 |
–71.54 |
0.28 |
–99.33 |
|
Tm+Mtm plus Pd |
28.31 |
–94.48 |
2.42 |
–93.58 |
7.81 |
–98.29 |
0.26 |
–99.38 |
|
Tm+Mtm plus Msm+Im |
32.75 |
–93.61 |
3.98 |
–89.45 |
4.69 |
–98.97 |
10.41 |
–75.14 |
|
Tm
+ Mtm plus Fn |
60.30 |
–88.23 |
3.85 |
–89.79 |
57.82 |
–87.31 |
2.35 |
–94.39 |
|
Pd
plus Flm |
53.44 |
–89.57 |
3.13 |
–91.70 |
25.00 |
–94.51 |
0.74 |
–98.23 |
|
Pd
plus Flm+Ap |
42.19 |
–91.77 |
2.02 |
–94.64 |
15.81 |
–96.53 |
1.66 |
–96.04 |
|
Msm+Im plus Flm |
63.75 |
–87.56 |
2.88 |
–92.36 |
28.12 |
–93.83 |
1.39 |
–96.68 |
|
Msm+Im plus Flm+Ap |
59.38 |
–88.41 |
3.21 |
–91.49 |
16.38 |
–96.40 |
12.56 |
–70.00 |
|
Fn plus Flm |
156.00 |
–69.56 |
15.58 |
–58.68 |
133.00 |
–70.81 |
2.68 |
–93.60 |
|
Fn plus Flm+Ap |
32.82 |
–93.60 |
1.81 |
–95.20 |
38.94 |
–91.45 |
5.72 |
–86.34 |
|
Hw |
60.62 |
–88.17 |
6.04 |
–83.98 |
30.00 |
–93.42 |
41.87 |
0.00 |
|
Ct |
512.50 |
0.00 |
37.71 |
0.00 |
455.62 |
0.00 |
8.58 |
–79.51 |
|
LSD (P≤ 0.05) |
184.69 |
– |
11.31 |
– |
180.25 |
– |
10.58 |
– |
Where
Tm+Mtm=Tribenuron methyl + metsulfuron methyl; Pd=Pinoxaden
(with cloquintocet-mexyl safener); Msm+Im=Mesosulfuron-methyl + iodosulfuron-methyl-sodium; Fn=Fenoxaprop-p-ethyl;
Flm=Fluroxypyr meptyle; Flm+Ap=Fluroxypyr meptyle + amino pyralid; Ce=Carfentrazone-ethyl; Tm+Mtm plus Pd=Tribenuron methyl
+ metsulfuron methyl plus pinoxaden;
Tm+Mtm plus Msm+Im=Tribenuron methyl + metsulfuron
methyl plus Mesosulfuron-methyl + iodosulfuron-methyl-sodium;
(Tm + Mtm plus Fn=Tribenuron methyl + metsulfuron
methyl plus Fenoxaprop-p-ethyl; Pd plus Flm=Pinoxaden plus Fluroxypyr meptyle; Pd plus Flm+Ap=Pinoxaden plus Fluroxypyr meptyle + amino pyralid; Msm+Im plus Flm=Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle; Msm+Im plus Flm+Ap=Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle +
amino pyralid; Fn plus Flm= Fenoxaprop-p-ethyl plus Fluroxypyr
meptyle; Fn plus Flm+Ap=
Fenoxaprop-p-ethyl plus Fluroxypyr meptyle + amino pyralid; Hw=hand weeding; Ct=Control
All the
chemical applications either sole or in combinations reduced both weed density
and significantly as compared to weedy check during both the years. In case of
sole application, mesosulfuron-methyl + iodosulfuron-methyl-sodium reduced the
weed density by 91 and 92% in 2017–2018 and 2018–2019, respectively. Likewise,
all the combinations have weed density reduction by 88–94% and 90–99% in 2017–2018
and 2018–2019, respectively as compared to weedy check plots except
fenoxaprop-p-ethyl plus fluroxypyr meptyle that reduced the density only by 70
and 59% (Table 7). In case of
weed biomass, all the chemical applications either sole or in combinations
reduced total weed biomass significantly as compared to weedy check plots
during both the years (Table 7).
In case of sole application, mesosulfuron-methyl + iodosulfuron-methyl-sodium
reduced weed biomass by 91 and 93% in 2017–2018 and 2018–2019, respectively.
Similarly, all the combinations have weed biomass reduction by 18–95% and
20–98% in 2017–2018 and 2018–2019 (Table
7), respectively as compared to season long weedy plots except
tribenuron methyl + metsulfuron methyl and fluroxypyr meptyle in 2017–2018 (Table 7).
Grain yield
components and grain yield
Table 8: Effect of
different weed control measures on grain yield components and grain yield
during 2017–2018 and 2018–2019
|
Treatments |
2017–2018 |
2018–2019 |
||||||||||
|
Number of spikes m-2 |
Number of grains spike-1 |
1000 grain weight (g) |
Grain yield (t ha-1) |
Straw yield (t ha-1) |
Harvest Index |
Number of spikes m-2 |
Number of grains spike-1 |
1000 grain weight (g) |
Grain yield (t ha-1) |
Straw yield (t ha-1) |
Harvest Index |
|
|
Tm
+ Mtm |
305.00 |
35.3 |
39.56 |
3.50 |
7.35 |
0.32 |
375.31 |
27.5 |
43.86 |
3.11 |
8.65 |
0.26 |
|
Pd |
354.69 |
32.0 |
46.65 |
4.10 |
9.70 |
0.30 |
389.06 |
31.6 |
40.89 |
4.21 |
10.15 |
0.29 |
|
Msm + Im |
460.00 |
39.8 |
42.68 |
4.49 |
9.80 |
0.31 |
507.81 |
40.5 |
36.58 |
4.72 |
9.50 |
0.33 |
|
Fn |
398.44 |
31.5 |
51.33 |
3.06 |
7.10 |
0.30 |
354.69 |
32.8 |
39.66 |
3.32 |
9.50 |
0.26 |
|
Flm |
295.31 |
32.9 |
39.01 |
3.05 |
6.90 |
0.31 |
245.30 |
29.0 |
44.88 |
3.03 |
6.95 |
0.3 |
|
Flm + Ap |
350.00 |
33.1 |
61.04 |
2.71 |
8.60 |
0.24 |
256.25 |
39.1 |
46.04 |
2.66 |
5.95 |
0.31 |
|
Ce |
290.62 |
35.3 |
39.69 |
2.20 |
5.10 |
0.30 |
368.75 |
29.7 |
44.51 |
2.24 |
7.65 |
0.23 |
|
Tm
+ Mtm plus Pd |
432.81 |
38.2 |
46.98 |
5.21 |
11.15 |
0.32 |
421.88 |
39.1 |
48.76 |
5.38 |
12.20 |
0.31 |
|
Tm
+ Mtm plus Msm + Im |
396.88 |
36.7 |
44.09 |
4.82 |
10.15 |
0.32 |
415.62 |
36.2 |
46.94 |
4.82 |
10.15 |
0.32 |
|
Tm
+ Mtm plus Fn |
354.69 |
35.6 |
48.15 |
3.73 |
7.95 |
0.32 |
418.75 |
35.6 |
36.02 |
4.03 |
10.25 |
0.28 |
|
Pd
plus Flm |
325.00 |
29.7 |
50.04 |
4.48 |
13.23 |
0.25 |
354.69 |
27.5 |
33.75 |
4.86 |
9.50 |
0.34 |
|
Pd
plus Flm + Ap |
331.25 |
28.7 |
43.47 |
4.77 |
9.40 |
0.34 |
410.94 |
39.1 |
40.76 |
4.77 |
9.40 |
0.34 |
|
Msm + Im plus Flm |
404.69 |
39.1 |
39.18 |
5.31 |
5.60 |
0.49 |
515.62 |
41.6 |
46.96 |
5.25 |
8.15 |
0.39 |
|
Msm + Im plus Flm + Ap |
442.19 |
35.6 |
39.35 |
4.50 |
7.25 |
0.38 |
590.62 |
40.2 |
37.28 |
4.92 |
9.35 |
0.34 |
|
Fn plus Flm |
368.75 |
34.3 |
41.25 |
4.06 |
10.50 |
0.28 |
303.12 |
35.7 |
42.52 |
4.16 |
8.10 |
0.34 |
|
Fn plus Flm + Ap |
442.19 |
31.0 |
45.30 |
3.87 |
5.75 |
0.40 |
468.75 |
37.8 |
50.23 |
4.64 |
7.65 |
0.38 |
|
Hw |
382.81 |
34.8 |
39.51 |
5.55 |
7.25 |
0.43 |
504.69 |
40.9 |
62.09 |
5.32 |
12.95 |
0.29 |
|
Ct |
171.88 |
23.6 |
38.87 |
2.04 |
5.25 |
0.28 |
184.38 |
27.9 |
36.54 |
2.16 |
7.00 |
0.24 |
|
LSD (P ≤ 0.05) |
70.93 |
8.48 |
10.91 |
0.89 |
8.48 |
0.14 |
83.31 |
4.79 |
9.46 |
0.94 |
7.84 |
0.12 |
Where, Tm + Mtm = Tribenuron methyl + metsulfuron methyl; Pd = Pinoxaden
(with cloquintocet-mexyl safener); Msm + Im = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; Fn
= Fenoxaprop-p-ethyl; Flm = Fluroxypyr
meptyle; Flm + Ap = Fluroxypyr meptyle + amino pyralid; Ce = Carfentrazone-ethyl;
Tm + Mtm plus Pd = Tribenuron
methyl + metsulfuron methyl plus pinoxaden;
Tm + Mtm plus Msm + Im = Tribenuron methyl + metsulfuron methyl plus Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; (Tm + Mtm plus Fn = Tribenuron
methyl + metsulfuron methyl plus Fenoxaprop-p-ethyl;
Pd plus Flm = Pinoxaden
plus Fluroxypyr meptyle; Pd
plus Flm + Ap = Pinoxaden
plus Fluroxypyr meptyle +
amino pyralid; Msm + Im plus Flm = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium plus Fluroxypyr
meptyle; Msm + Im plus Flm + Ap = Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle +
amino pyralid; Fn plus Flm = Fenoxaprop-p-ethyl plus Fluroxypyr
meptyle; Fn plus Flm + Ap = Fenoxaprop-p-ethyl plus Fluroxypyr
meptyle + amino pyralid; Hw = hand weeding; Ct = Control
Number of
spikes m-2 of wheat was significantly affected by weed control
treatments (Table 8). All the chemical sole or in combination produced higher
numbers of spikes as compared with the control. The weed control treatments viz., manual hand weeding,
mesosulfuron-methyl + iodosulfuron-methyl-sodium either applied alone (460 and
508 spikes m-2) or in combination with fluroxypyr meptyle + amino
pyralid (442 and 590 spikes m-2) and fluroxypyr
meptyle (404 and 515 spikes m-2) produced
relatively higher number of spikes than other weed control treatments (172 and
184 spikes m-2) during 2017–18 and 2018–19, respectively. Whereas,
lower spike density (295 and 245 spikes m-2) among the chemical
treatments was observed with fluroxypyr meptyle in 2017–2018 and 2018–2019,
respectively (Table 8). As far as number of grains spike-1 is
concerned, it was recorded that the plots applied with the sole application of
mesosulfuron-methyl + iodosulfuron-methyl-sodium (40 and 41 grains spike-1),
its combinations with fluroxypyr meptyle (39 and 42 grains spike-1)
and fluroxypyr meptyle + amino pyralid (36 and 40 grains spike-1)
during 2017–2018 and 2018–2019, respectively (Table 8). The treatment
tribenuron methyl + metsulfuron methyl plus pinoxaden (38 and 39 grains spike-1)
also produced higher number of grains spike-1 as compared to other
treatments during first and second year respectively. The lowest number of
grains spike-1 (24 and 28) was observed from control treatment
during both years (Table 8). Among different herbicide treatments, maximum 1000
grain weight was achieved from fluroxypyr meptyle + amino pyralid (61.04 g) followed by applications of fenoxaprop-p-ethyl
(51.33 g), pinoxaden plus fluroxypyr meptyle (50.04g) and tribenuron methyl + metsulfuron methyl plus pinoxaden (48.15 g) as compared with the control during the year
2017–18 (Table 8). In the
second year (2018–2019) maximum 1000 grain weight was observed from the weed
free plots (62.09 g) followed by herbicide application of fenoxaprop-p-ethyl
plus fluroxypyr meptyle + amino pyralid (50.23 g) and tribenuron methyl +
metsulfuron methyl plus pinoxaden (48.76 g) (Table 8). The minimum 1000 grain weight was observed (38.87 and
36.54 g) for weed check plot in 2017-2018 and 2018–2019, respectively (Table
8).
Table 9: Production cost (US $ ha-1) of different weed
control measures during 2017–2018 and 2018–2019
|
Production
cost (US $ ha-1) |
||||||||
|
Treatments |
Weed
Management cost |
Land
preparation/ sowing
cost |
Seed
cost |
Fertilizer
cost |
Irrigation
cost |
Crop
Management cost |
Harvesting
cost |
Total
production cost |
|
Tm
+ Mtm |
10.50 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
378.22 |
|
Pd |
14.67 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
382.39 |
|
Msm + Im |
16.98 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
384.70 |
|
Fn |
16.98 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
384.70 |
|
Flm |
19.68 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
387.41 |
|
Flm + Ap |
10.03 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
377.76 |
|
Ce |
8.10 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
375.83 |
|
Tm
+ Mtm plus Pd |
25.16 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
392.89 |
|
Tm
+ Mtm plus Msm + Im |
27.48 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
395.20 |
|
Tm
+ Mtm plus Fn |
27.48 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
395.20 |
|
Pd
plus Flm |
34.35 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
402.07 |
|
Pd
plus Flm + Ap |
24.70 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
392.42 |
|
Msm + Im plus Flm |
36.66 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
404.39 |
|
Msm + Im plus Flm + Ap |
27.02 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
394.74 |
|
Fn plus Flm |
36.66 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
404.39 |
|
Fn plus Flm + Ap |
27.02 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
394.74 |
|
Hw |
123.50 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
491.22 |
|
Ct |
0.00 |
43.23 |
38.59 |
163.64 |
37.05 |
48.17 |
37.05 |
367.72 |
Where,
PKR is Pakistan’s currency. US$1 = PKR 160. (Weeding cost = 25 man days x US$
4.9375 per day). Tm + Mtm = Tribenuron
methyl + metsulfuron methyl; Pd = Pinoxaden
(with cloquintocet-mexyl safener); Msm + Im = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; Fn
= Fenoxaprop-p-ethyl; Flm = Fluroxypyr
meptyle; Flm + Ap = Fluroxypyr meptyle + amino pyralid; Ce = Carfentrazone-ethyl;
Tm + Mtm plus Pd = Tribenuron
methyl + metsulfuron methyl plus pinoxaden;
Tm + Mtm plus Msm + Im = Tribenuron methyl + metsulfuron methyl plus Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; (Tm + Mtm plus Fn = Tribenuron
methyl + metsulfuron methyl plus Fenoxaprop-p-ethyl;
Pd plus Flm = Pinoxaden
plus Fluroxypyr meptyle; Pd
plus Flm + Ap = Pinoxaden
plus Fluroxypyr meptyle +
amino pyralid; Msm + Im plus Flm = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium plus Fluroxypyr
meptyle; Msm + Im plus Flm + Ap = Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle +
amino pyralid; Fn plus Flm = Fenoxaprop-p-ethyl plus Fluroxypyr
meptyle; Fn plus Flm + Ap=
Fenoxaprop-p-ethyl plus Fluroxypyr meptyle + amino pyralid; Hw = hand weeding; Ct = Control
Table 10: Economics of different weed control measures on grand
income, net profit and cost-benefit ratio for 2017–2018 and 2018–2019
|
Treatments |
|
2017-2018 |
2018-2019 |
||||||||
|
|
Total cost
(US $ ha-1) |
Grain yield
income ($ ha-1) |
Straw
income ($ ha-1) |
Grand
income ($ ha-1) |
Net profit
($ ha-1) |
Cost-benefit
ratio |
Grain yield
income ($ ha-1) |
Straw
income ($ ha-1) |
Grand
Income ($ ha-1) |
Net profit
($ ha-1) |
Cost-benefit
ratio |
|
Tm
+ Mtm |
378.22 |
875.00 |
57.42 |
932.42 |
554.20 |
1.47 |
778 |
67.58 |
845.08 |
466.86 |
1.23 |
|
Pd |
382.39 |
1025.00 |
75.78 |
1100.78 |
718.39 |
1.88 |
1053 |
79.30 |
1131.80 |
749.41 |
1.96 |
|
Msm + Im |
384.70 |
1122.50 |
76.56 |
1199.06 |
814.36 |
2.12 |
1180 |
74.22 |
1254.22 |
869.52 |
2.26 |
|
Fn |
384.70 |
765.00 |
55.47 |
820.47 |
435.77 |
1.13 |
830 |
74.22 |
904.22 |
519.52 |
1.35 |
|
Flm |
387.41 |
762.50 |
53.91 |
816.41 |
429.00 |
1.11 |
758 |
54.30 |
811.80 |
424.39 |
1.10 |
|
Flm + Ap |
377.76 |
677.50 |
67.19 |
744.69 |
366.93 |
0.97 |
665 |
46.48 |
711.48 |
333.73 |
0.88 |
|
Ce |
375.83 |
550.00 |
39.84 |
589.84 |
214.02 |
0.57 |
560 |
59.77 |
619.77 |
243.94 |
0.65 |
|
Tm
+ Mtm plus Pd |
392.89 |
1302.50 |
87.11 |
1389.61 |
996.72 |
2.54 |
1345 |
95.31 |
1440.31 |
1047.43 |
2.67 |
|
Tm
+ Mtm plus Msm + Im |
395.20 |
1205.00 |
79.30 |
1284.30 |
889.10 |
2.25 |
1205 |
79.30 |
1284.30 |
889.10 |
2.25 |
|
Tm
+ Mtm plus Fn |
395.20 |
932.50 |
62.11 |
994.61 |
599.41 |
1.52 |
1008 |
80.08 |
1087.58 |
692.38 |
1.75 |
|
Pd
plus Flm |
402.07 |
1120.00 |
103.36 |
1223.36 |
821.29 |
2.04 |
1215 |
74.22 |
1289.22 |
887.15 |
2.21 |
|
Pd
plus Flm + Ap |
392.42 |
1192.50 |
73.44 |
1265.94 |
873.52 |
2.23 |
1193 |
73.44 |
1265.94 |
873.52 |
2.23 |
|
Msm + Im plus Flm |
404.39 |
1327.50 |
43.75 |
1371.25 |
966.86 |
2.39 |
1313 |
63.67 |
1376.17 |
971.79 |
2.40 |
|
Msm + Im plus Flm + Ap |
394.74 |
1125.00 |
56.64 |
1181.64 |
786.90 |
1.99 |
1230 |
73.05 |
1303.05 |
908.31 |
2.30 |
|
Fn plus Flm |
404.39 |
1015.00 |
82.03 |
1097.03 |
692.64 |
1.71 |
1040 |
63.28 |
1103.28 |
698.89 |
1.73 |
|
Fn plus Flm + Ap |
394.74 |
967.50 |
44.92 |
1012.42 |
617.68 |
1.56 |
1160 |
59.77 |
1219.77 |
825.03 |
2.09 |
|
Hw |
367.72 |
510.00 |
56.64 |
1444.14 |
952.92 |
1.94 |
1330 |
101.17 |
1431.17 |
939.95 |
1.91 |
|
Ct |
491.22 |
1387.50 |
41.02 |
551.02 |
183.29 |
0.50 |
540 |
54.69 |
594.69 |
226.97 |
0.62 |
Where, PKR is
currency of Pakistan, PKR 160 = US$1,
market price of wheat = 250 $ t-1, market price of straw = 3.85 $ t-1,
grand income = [(wheat grain yield × market price of wheat t-1) +
(straw yield × market price of straw t-1)], net profit= (grand
income – total cost of production). benefit-cost ratio = net benefit / total
cost of production); Tm + Mtm = Tribenuron
methyl + metsulfuron methyl; Pd = Pinoxaden
(with cloquintocet-mexyl safener); Msm + Im = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; Fn
= Fenoxaprop-p-ethyl; Flm = Fluroxypyr
meptyle; Flm + Ap = Fluroxypyr meptyle + amino pyralid; Ce = Carfentrazone-ethyl;
Tm + Mtm plus Pd = Tribenuron
methyl + metsulfuron methyl plus %20479-489_files/image002.png)
Fig. 1: Relationship between weeds biomass and wheat grain yield
during 2017-2018 (a) and 2018-2019 (b)
pinoxaden; Tm + Mtm plus Msm + Im = Tribenuron
methyl + metsulfuron methyl plus Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium; (Tm + Mtm plus Fn = Tribenuron
methyl + metsulfuron methyl plus Fenoxaprop-p-ethyl;
Pd plus Flm = Pinoxaden
plus Fluroxypyr meptyle; Pd
plus Flm + Ap = Pinoxaden
plus Fluroxypyr meptyle +
amino pyralid; Msm + Im plus Flm = Mesosulfuron-methyl
+ iodosulfuron-methyl-sodium plus Fluroxypyr
meptyle; Msm + Im plus Flm + Ap = Mesosulfuron-methyl + iodosulfuron-methyl-sodium
plus Fluroxypyr meptyle +
amino pyralid; Fn plus Flm = Fenoxaprop-p-ethyl plus Fluroxypyr
meptyle; Fn plus Flm + Ap =
Fenoxaprop-p-ethyl plus Fluroxypyr meptyle + amino pyralid; Hw = hand weeding; Ct = Control
All weed control treatments improved grain yield over
control during both years (Table 8). The highest grain yield (5.55 t ha-1)
was recorded from manual weeding followed by chemical weed control by
mesosulfuron-methyl + iodosulfuron-methyl-sodium plus fluroxypyr meptyle (5.31
t ha-1) during 2017–2018, whereas in 2018–2019 mesosulfuron-methyl +
iodosulfuron-methyl-sodium plus fluroxypyr meptyle (5.38 t ha-1)
produced more grain yield over all the treatments including hand weeding. The
grain yield (2.04 and 2.2 t ha-1) was lowest for the control
treatment in first and second year (Table 8). The straw yield significantly
affected by the weed control methods and most of the treatments had higher
straw yield over the control during both years (Table 8). In 2017–2018, maximum
straw yield (13.23 t ha-1) was produced from the treatment pinoxaden
plus fluroxypyr meptyle followed by tribenuron methyl + metsulfuron methyl plus
pinoxaden (11.15 t ha-1) and fenoxaprop-p-ethyl plus fluroxypyr
meptyle (10.50 t ha-1). In 2018–2019 (Table 8), the highest straw
yield was achieved in hand weeding treatment (12.95 t ha-1) followed
by tribenuron methyl + metsulfuron methyl plus pinoxaden (12.20 t ha-1)
and tribenuron methyl + metsulfuron methyl plus fenoxaprop-p-ethyl (10.25 t ha-1).
The lowest straw yield was recorded from the sole application of fluroxypyr
meptyle + amino pyralid (5.95 t ha-1) followed by Fluroxypyr meptyle
(6.95 t ha-1) and control treatment (7.00 t ha-1). For
the harvest index, the highest was observed in mesosulfuron-methyl + iodosulfuron-methyl-sodium plus fluroxypyr
meptyle (0.49 and 0.39) and fenoxaprop-p-ethyl plus
fluroxypyr meptyle + amino pyralid (0.40 and 0.38) in 2017–2018 and 2018–2019,
respectively as compared to weedy check plots where it was minimum in both the
years (Table 8).
Cost-benefit
ratio (CBR)
The highest CBR was achieved with tribenuron methyl +
metsulfuron methyl plus pinoxaden (2.54 and 2.67) and mesosulfuron-methyl +
iodosulfuron-methyl-sodium plus Fluroxypyr meptyle (2.39 and 2.40) in 2017–2018
and 2018–2019, respectively as compared to control treatment (Table 9 and 10).
Relationship
between weed biomass and wheat grain Yield
The
above-ground biomass of weeds and yield of wheat were negatively correlated
with each other in each year, as weeds biomass increased, the analogous decline
in wheat grain yield was observed. Regression results depicted that each 1 g m-2
weed biomass increase resulted in a decrease of 56 and 64 kg ha-1 of
wheat grain yield at harvest during 2017–2018 and 2018–2019, respectively (Fig.
1a, b).
Discussion
Application of mixed herbicides can
prevent evolution of herbicide-resistant weeds because of using more than one
active ingredient (Galon et al. 2018). The results showed reduction in
density and biomass of littleseed canarygrass in all herbicide
combinations except sole application of fluroxypyr meptyle, tribenuron methyl +
metsulfuron methyl, carfentrazone-ethyl and cluroxypyr meptyle + amino pyralid
that remained ineffective to suppress this weed. Fenoxaprop-p-ethyl, pinoxaden
and Mesosulfuron-methyl + iodosulfuron-methyl-sodium decreased the density and
biomass of littleseed canarygrass efficiently either applied alone or in
different combinations. Some of the previous studies also reported decline in
total weeds density by 96% with application of mesosulfuron-methyl +
iodosulfuron-methyl-sodium at the rate of 14.4 g a.i. ha-1 (Razzaq et
al. 2012) because the herbicides inhibiting the activity of Acetyl CoA
carboxylase (ACCase) enzyme proved effective against littleseed canarygrass.
Moreover, in another study, pinoxaden, fenoxaprop plus metribuzin and
mesosulfuron plus iodosulfuron were equally effective on littleseed canarygrass
when applied at main stem and one tiller stage
of wheat. Application of pinoxaden at main stem and three tiller stage
of wheat, gave more than 90% control of littleseed canarygrass and the highest
wheat grain yield (Rasool et al. 2017). However, these results are
contrary to those of Chhokar and Sharma (2008) who observed resistance of
littleseed canarygrass to ACCase inhibitors, photosynthesis at the photosystem
II site A and acetolactate synthase inhibition in India.
The results of this study demonstrated effectiveness of
fluroxypyr meptyle, fluroxypyr meptyle + amino pyralid, carfentrazone-ethyl,
Mesosulfuron-methyl + iodosulfuron-methyl-sodium and tribenuron methyl +
metsulfuron methyl against density and biomass of yellow pea. The control of the weed may be ascribed to
action of the herbicides on normal functioning of ALS and the disruption of
cell division in meristematic tissues. Pinoxaden and fenoxaprop-p-ethyl
were failed to control the weed possibly due to resistance of the weed against
ACCase mode of action. In a previous study, it was also found that plastids of
dicotyledonous plants contain herbicide-resistant multisubunit ACCases (Tong
2013). Bur clover also
demonstrated similar response against all treatments as observed in case of yellow pea. Fenoxaprop-p-ethyl and
pinoxaden were also found helpless against these weeds. The control of the
weeds from other treatments was obtained due to the vulnerability of the weed
towards ALS and disruption of mitotic cell division modes of actions. The weed
was among the broad-leaved weeds that were found resistant to ACCase mode of
action (Tong 2013).
Wheat tiller density was improved
by all weed control treatments and it might be attributed to better weed
control which decreased crop weed competition so the resources were better
utilized by the crop to produce higher number of productive tillers per unit
area (Hussain et al. 2014).
Combined application of herbicides increased number of tillers better than sole
application due to efficient weed management. The low tiller density from
control plots may be due to higher crop-weed competition during the study
(Cheema and Akhtar 2005; Hussain et al. 2017; Naeem et al. 2021).
Hence, weeds are the worst competitors for
draining more resources like space, light, air etc. due to vigorous
growth (Leghari et al. 2015). Herbicide combinations, controlling both type
of weeds (broad leaf and grasses) and hand weeding improved number of grains spike-1
better than sole herbicide application. The study results depicted that the
number of grains spike-1 can be increased by controlling weeds (Alvi
et al. 2004). Therefore,
it is inevitable to manage grassy and broad leaf weeds for obtaining higher
number of grains spike-1 in wheat which contribute mainly to grain
yield. Similarly, grain weight is
another important component mainly contributing to grain yield and our study
demonstrated that good growth conditions observed for weed free plots
produced healthier crop ultimately having more grain weight. This might be
because of better source sink relationship at grain formation stage (Hussain et
al. 2003; Alvi et al.
2004).
Grain yield contributing parameters and grain yield were
affected significantly by chemical weed management and increased grain yield
over control treatment. This increase in grain yield may be ascribed to better
weed control leading to more number of fertile tillers, better crop growth,
higher number of grains spike-1 and heavier grains. Hand weeding
increased the yield to maximum level due to efficient weed management. All
herbicide combinations also increased yield to almost similar level as attained
by hand weeding. Earlier studies also reported similar wheat yield by hand
weeding and application of mesosulfuron-methyl + iodosulfuron-methyl-sodium 3.6
WG & 14.4 g a.i. ha-1 (Ashraf and Akhlaq 2007; Hussain et al. 2014). Lower crop yields obtained
from the control treatment may be attributed to intensive weed-crop
competition, depleting the soil from essential nutrients and eventually
depriving of the crop requirements. Results of our study confirmed earlier
findings that weeds compete with crop for essential resources and eventually
lower crop yields (Khan and Marwat 2006; Leghari et al. 2015). The
results of the study depicted a negative correlation between weeds biomass and
wheat grain yield. Weed biomass is adversely correlated with grain yield of wheat. Results showed that the increased
biomass of weeds correspondingly reduced the wheat biomass and grain yield in
both years. The reason might be that weeds consume the major portion of the
nutrients, reducing their availability to the
wheat plants and resulting in low wheat
biomass and grain production (Khan and Marwat 2006).
Conclusion
It is
imperative to control both broad and narrow leaf weeds for obtaining maximum
wheat crop yields that can be achieved by the application of either broad
spectrum herbicides or herbicide combinations capable of controlling both types
of weeds. Results of this study concluded that herbicides combinations
mesosulfuron-methyl + iodosulfuron-methyl-sodium plus fluroxypyr meptyle, and
tribenuron methyl + metsulfuron methyl plus pinoxaden were the most effective
and economical to get higher economical yield by managing wheat weeds.
Author Contributions
THA and SI planned, designed, executed the experiments
and wrote the manuscript, MUS analyzed the data statistically, SH wrote the
discussion, UBK compiled the data and SA revised and improved the language of
the manuscript.
Conflict of Interest
The authors declare that they have no conflicts of
interest.
Ethics Approval
The authors declare that the work is written with due
consideration of ethical standards. The study was conducted in accordance with
the ethical principles approved by the Ethics Committee of Federal State
Budgetary Educational Establishment of Higher Education “Bashkir State Agrarian
University” (Protocol № 6 of 13.06.2020).
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