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Bioefficacy of different herbicides for control of weeds in direct seeded rice

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Simerjeet Kaur at Punjab Agricultural University
Simerjeet Kaur
Surjit Singh
Surjit Singh
Surjit Singh
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Abstract

Field experiment was conducted during Kharif 2009 and 2010 to study the bio-efficacy of different herbicides in direct-seeded rice. Weed control treatments comprised of pendimethalin 0.75 kg, butachlor 1.50 kg, thiobencarb 1.50 kg, anilofos 0.375 kg, pretilachlor 0.75 kg, oxadiargyl 0.09 kg and pyrazosulfuron ethyl 0.015 kg/ha as pre-emergence and with sequential application of bispyribac 0.025 kg/ha at 30 DAS; two hand weedings and unweeded control. Significantly lower number of grass weeds was observed with application of pendimethalin as compared with other pre-emergence herbicides. Sequential application of pendimethalin and bispyribac recorded the lowest weed biomass and 100% weed control efficiency. Crop dry matter accumulation, number of tillers, and effective tillers were significantly higher in sequential use of pre- and post-emergence herbicides, resulting in more grain yield and net returns. The maximum grain yield was recorded in two hand weedings, which was at par with follow-up application of bispyribac after pendimethalin, butachlor, thiobencarb and oxadiargyl.
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106
Indian Journal of Weed Science 47(2): 106–109, 2015
Bio-efficacy of different herbicides for weed control in direct-seeded rice
Simerjeet Kaur* and Surjit Singh
Department of Agronomy, Punjab Agricultural University, Ludhiana, Punjab 141 004
Received: 5 April 2015; Revised: 8 June 2015
ABSTRACT
Field experiment was conducted during Kharif 2009 and 2010 to study the bio-efficacy of different
herbicides in direct-seeded rice. Weed control treatments comprised of pendimethalin 0.75 kg, butachlor
1.50 kg, thiobencarb 1.50 kg, anilofos 0.375 kg, pretilachlor 0.75 kg, oxadiargyl 0.09 kg and pyrazosulfuron
ethyl 0.015 kg/ha as pre-emergence and with sequential application of bispyribac 0.025 kg/ha at 30 DAS;
two hand weedings and unweeded control. Significantly lower number of grass weeds was observed
with application of pendimethalin as compared with other pre-emergence herbicides. Sequential
application of pendimethalin and bispyribac recorded the lowest weed biomass and 100% weed control
efficiency. Crop dry matter accumulation, number of tillers, and effective tillers were significantly higher
in sequential use of pre- and post-emergence herbicides, resulting in more grain yield and net returns.
The maximum grain yield was recorded in two hand weedings, which was at par with follow-up
application of bispyribac after pendimethalin, butachlor, thiobencarb and oxadiargyl.
Key words: Direct-seeded rice, Economics, Grain yield, Herbicides, Weed control efficiency
Weeds are the main constraint in direct-seeded
rice since the inherent weed control from standing
water at crop establishment is lost (Rao et al. 2007).
In direct-seeded rice, high weed infestation causes
grain yield losses up to 90%. Weeds pose a serious
threat by competing for nutrients, light, space and
moisture just from the time of emergence and
throughout the growing season, whereas weed seeds
germinate after rice transplanting in transplanted rice
and compete with the well-established rice seedlings.
A change in crop establishment method from
transplanting to direct seeding brings about changes
in the weed community; grasses – Dactyloctenium
aegyptium, Digitaria ciliaris, Eragrostis spp.,
Eleusine indica, Acrachne racemosa, Commelina
benghale-nsis; sedges - Cyperus compressus, Cyperus
rotundus and broad-leaved –Digera arvensis,
Phyllanthus niruri, Amaranthus viridis and
Trianthema portulacastrum have also started
appearing in rice fields along with Echinochloa crus-
galli, Echinochloa colona, Leptochloa chinensis,
Cyperus iria, Cyperus difformis, Eclipta alba,
Sphenochloa zeylenica etc. So, conversion from
transplanted to direct-seeded rice results in more
competitive weed flora requiring revised weed
management approaches for effective control. A
weed-free period for the first 25-45 DAS is required
to avoid any loss in yield in dry direct-seeded rice
(Chauhan and Johnson 2011, Singh et al. 2012).
Hand weeding operations are laborious, time
consuming, uneconomical, difficult and moreover,
result in uprooting of some rice seedlings due to
difficulty in differentiating grass weeds that mimic
rice plants during early growth. Some herbicides
found effective in DSR are pendimethalin, cyhalofop-
butyl, fenoxaprop-ethyl, propanil, bispyribac-sodium,
penoxsulam, carfentrazone-ethyl, bensulfuron,
metsulfuron + chlorimuron, azimsulfuron and 2,4-D.
In Punjab state, seven pre-emergence herbicides
namely pendimethalin, butachlor, thiobencarb,
anilofos, pretilachlor, oxadiargyl and pyrazosulfuron-
ethyl have been recommended in puddled
transplanted rice. Identifying herbicides with wide-
spectrum weed control ability for efficient and
economical weed management is crucial for
improving the potential of direct seeding of rice.
Keeping this in view, an experiment was conducted to
study the bio-efficacy of different pre- and post-
emergence herbicides used in conventional puddled
transplanted rice in direct-seeded rice.
MATERIALS AND METHODS
The field experiment was conducted at
Research Farm, Department of Agronomy, Punjab
Agricultural University, Ludhiana during Kharif
season of 2009 and 2010. Ludhiana is situated in
Trans-Gangetic Agro-Climatic zone, representing the
Indo-Gangetic Alluvial plains at 30°56' N latitude,
75°52' E longitude and at an altitude of 247 m above
mean sea level. The maximum temperature remained
above 38° C during summer. The total rainfall of 818
*Corresponding author: simer@pau.edu
107
and 627.6 mm were received during 2009 and 2010,
respectively. Most of the rainfall was received in
vegetative phase from 23rd (at sowing time) to 35th
standard meteorological week (80 days after
sowing). The soil of the experimental site was loamy
sand with normal soil reaction of pH 7.5 and electrical
conductivity of 0.16 dS/m. The soil was low in
organic C (0.31%) and available N (251.7 kg/ha) and
medium in available P (13.5 kg/ha) and K (164.1 kg/
ha). The crop was sown with conventional seed-
cum-fertilizer drill at 20 cm row to row spacing with
seed rate of 35 kg/ha.
Sixteen weed control treatments comprised of
pre-emergence application of pendimethalin 0.75 kg,
butachlor 1.50 kg, thiobencarb 1.50 kg, anilofos
0.375 kg, pretilachlor 0.75 kg, oxadiargyl 0.09 kg and
pyrazosulfuron-ethyl 0.015 kg/ha, and each unlined
with sequential application of bispyribac 0.025 kg/ha
at 30 days after sowing (DAS), two hand weedings
and unweeded control. Pre-emergence herbicides
were sprayed in moist field within two days of
sowing and bispyribac was sprayed at 30 DAS as
follow-up. Pre- and post-emergence herbicides were
applied with knapsack sprayer fitted with flat fan
nozzle using 375 L/ha of water. Nitrogen (187.5 kg/
ha) was applied as broadcast in four equal splits at 2,
4, 7 and 10 weeks after sowing. Phosphorus (30 kg/
ha), potassium (30 kg/ha) and zinc sulphate
heptahydrate (62.5 kg/ha) were applied at the time of
seed-bed preparation by broadcasting. Plant
protection measures for insect-pests and diseases
were taken to grow healthy crop.
Data on weed population and dry matter, crop
growth and yield were recorded. Weed control
efficiency and benefit:cost ratio were calculated.
Weed data were square-root transformed before
statistical analysis. Pooled analysis of two years was
done and comparisons were made at 5% level of
significance.
RESULTS AND DISCUSSION
Weed population and dry matter
The predominant weed flora of the experimental
field were: Echinochloa crusgalli, Echinochloa
colona and Cyperus iria, Cyperus difformis at 30
DAS prior to post-emergence application of
bispyribac. Along with Echinochloa spp., other grass
weeds like Digitaria sanguinalis and Dactyloctenium
aegyptium were also reported but Cyperus spp. was
not observed at later stages of observation as most of
the rainfall was received during vegetative phase of
crop which led to smothering and perishing of weed
flora. Pendimethalin treated plots recorded
significantly lower number of Echinochloa spp. than
all other herbicides but have no effect on Cyperus
spp. (Table 1). Other pre-emergence herbicides, viz.
butachlor, thiobencarb, anilofos, pretilachlor,
oxadiargyl and pyrazosulfuron-ethyl, conventionally
used in puddled transplanted rice under Punjab
conditions were broadcast in standing water as pre-
emergence but in this study, these were applied on
moist soil as spray application. Similar results were
obtained by Singh et al. (2009) that under dry seeding
methods, effective weed control was recorded with
pre-emergence application of pendimethalin than
pretilachlor. Statistically similar number of Cyperus
spp. was observed with application of all pre-
emergence herbicides, resulting in non-significant
differences in weed dry matter. But, weed dry matter
was at par in pyrazosulfuron-ethyl and unweeded
control. One hand weeding done at 25 DAS has
significantly lower weed dry matter as compared
with other weed control treatments at 30 DAS.
Follow-up application of bispyribac controlled
Echinochloa spp. and Cyperus iria but had no control
over D. sanguinalis and D. aegyptium, however, D.
sanguinalis and D. aegyptium were controlled with
Table 1. Effect of weed control treatments on weed population and dry matter at 30 DAS in direct-seeded rice (mean of
two years)
Treatment Echinochloa spp. (no./m2) Cyperus spp. (no./m2) Weed dry matter (g/m2)
Pendimethalin 0.75 kg/ha 3.2 (10) 6.4 (40) 5.8 (33)
Butachlor 1.50 kg/ha 4.6 (21) 5.5 (30) 6.3 (38)
Thiobencarb 1.50 kg/ha 4.5 (19) 5.7 (32) 6.3 (38)
Anilofos 0.375 kg/ha 4.5 (19) 5.9 (34) 6.7 (45)
Pretilachlor 0.75 kg/ha 5.3 (27) 5.7 (32) 6.4 (41)
Oxadiargyl 0.09 kg/ha 5.1 (25) 5.3 (28) 7.3 (53)
Pyrazosulfuron-ethyl 0.015
kg/ha 6.4 (40) 6.2 (38) 8.9 (79)
Hand weeding at 25 DAS 1.0 (0) 1.0 (0) 1.0 (0)
Unweeded 9.6 (92) 14.5 (210) 9.1 (83)
LSD
(P=0.05)
0.5
0.8
0.8
The data are square root transformed and values in the parentheses are original values.
Bio-efficacy of different herbicides for weed control in direct-seeded rice
108
two hand weeding and pre-emergence application of
pendimethalin, was significantly superior to other
herbicides and unweeded control (Table 2). This
resulted in lowest weed dry matter and 100% weed
control efficiency. Walia et al. (2008) also reported
that pendimethalin application in dry-seeded rice
provided effective control of weeds not associated
with paddy crop, whereas bispyribac controlled all
typical predominant weeds including Echinochloa
spp. and all Cyperus spp. Bispyribac-sodium and
other pre-emergence herbicides, butachlor,
thiobencarb, anilofos, pretilachlor, oxadiargyl and
pyrazosulfuron-ethyl did not control these grass
weeds. Similar results were reported by Kumar and
Ladha (2011). Follow-up spray of bispyribac after
butachlor, thiobencarb, anilofos, pretilachlor,
oxadiargyl and pyrazosulfuron-ethyl resulted in
significantly lower weed dry matter than alone
application of pre-emergence herbicides, resulting in
88% weed control efficiency. Single application of
pre-emergence herbicides showed poor weed control
efficiency (19.0–24.2%) (Table 2).
Crop growth and yield
Follow-up application of bispyribac 0.025 kg/ha
at 30 DAS after pendimethalin 0.75 kg, butachlor
1.50 kg, thiobencarb 1.50 kg, anilofos 0.375 kg,
pretilachlor 0.75 kg, oxadiargyl 0.09 kg and
pyrazosulfuron-ethyl 0.015 kg/ha registered
significantly taller plants as compared with single
application of pre-emergence herbicides, resulting in
more crop dry matter production and effective tillers
(Table 3). Better crop growth in these treatments
might be attributed to more availability of nutrients,
water, light and space to crop as a result of effective
weed control. All weed control treatments recorded
significantly more number of effective tillers as
compared with unweeded control. Single application
of pre-emergence herbicides, viz. pendimethalin,
butachlor, thiobencarb, anilofos, pretilachlor and
oxadiargyl recorded significantly higher number of
effective tillers as compared with pyrazosulfuron-
ethyl as pre-emergence and unweeded control.
Number of grains/panicle was significantly higher in
sequential spray of pre- and post-emergence
herbicides than single application of pre-emergence
herbicides, except pendimethalin, which was at par
with unweeded control. The maximum grain yield
was recorded in two hand weedings which was at par
with sequential application of pendimethalin,
butachlor, thiobencarb and oxadiargyl with
bispyribac. Follow-up application of bispyribac
registered significantly more grain yield as compared
with single application of pre-emergence herbicides.
Table 2. Effect of weed control treatments on weeds in direct-seeded rice (mean of two years)
Data are square root transformed and values in the parentheses are original values
Simerjeet Kaur and Surjit Singh
Treatment
Weed count at 60 DAS (no./m
) Weed dry matter
(g/m2) Weed control
efficiency
at
harvest (%)
Echinochloa
spp. Cyperus
sp. Digitaria
sanguinalis
Dactyloct-
einum
aegyptium 60 DAS At harvest
Pendimethalin 0.75 3.4 (13) 2.7 (6) 1.0 (0) 1.0 (0) 8.1 (66) 27.3 (759) 30.4
Pendimethalin 0.75
fb
bispyribac
0.025 1.0 (0) 1.0 (0) 1.0 (0) 1.0 (0) 1.0 (0) 1.0 (0) 100.0
Butachlor 1.50 4.0 (19) 2.6 (6) 1.9 (3) 1.8 (2) 10.1 (101) 28.5 (823) 24.2
Butachlor 1.50 fb bispyribac 0.025 1.0 (0) 1.0 (0) 1.9 (3) 1.7 (2) 4.2 (18) 11.1 (123) 88.6
Thiobencarb 1.50 4.0 (19) 2.6 (6) 1.9 (3) 1.7 (2) 10.0 (101) 29.3 (865) 20.4
Thiobencarb 1.50
fb
bispyribac
0.025
1.0 (0) 1.0 (0) 2.0 (3) 1.7 (2) 4.3 (18) 11.2 (126) 88.3
Anilofos 0.375 4.1 (19) 2.8 (7) 1.9 (3) 1.7 (2) 10.0 (101) 29.2 (876) 19.5
Anilofos 0.375 fb bispyribac
0.025 1.0 (0) 1.0 (0) 1.9 (3) 1.8 (2) 4.3 (18) 10.9 (121) 88.7
Pretilachlor 0.75 4.2 (20) 2.5 (5) 1.9 (3) 1.8 (2) 9.8 (96) 29.0 (851) 21.9
Pretilachlor 0.75
fb
bispyribac
0.025 1.0 (0) 1.0 (0) 1.9 (3) 1.7 (2) 4.4 (20) 11.4 (129) 88.0
Oxadiargyl 0.09 4.0 (18) 2.6 (6) 1.9 (3) 1.7 (2) 10.4 (107) 29.1 (855) 21.4
Oxadiargyl 0.09 fb bispyribac
0.025 1.0 (0) 1.0 (0) 1.8 (3) 1.7 (2) 4.4 (19) 10.8 (120) 88.8
Pyrazosulfuron-ethyl 0.015 4.3 (21) 2.7 (7) 2.0 (3) 1.8 (2) 10.4 (108) 29.5 (882) 19.0
Pyrazosulfuron-ethyl 0.015 fb
bispyribac 0.025 1.0 (0) 1.0 (0) 2.0 (3) 2.0 (3) 4.3 (18) 11.2 (126) 88.3
Two hand weeding 1.0 (0) 1.0 (0) 1.0 (0) 1.0 (0) 1.0 (0) 10.6 (112) 89.4
Unweeded 6.1 (39) 2.8 (7) 2.1 (4) 1.9 (3) 17.2 (294) 32.7
(1077) -
LSD (P=0.05) 0.3 0.3 0.3 0.4 0.9 2.2
109
These results are in conformity with the findings of
Walia et al. (2009) and Mahajan and Timsina (2011).
Walia et al.(2008) also reported that it is difficult to
raise weed-free DSR with the application of only one
herbicide. The dry matter of weeds and grain yield
has an inverse relationship with r value of -0.98.
Amongst the pre-emergence herbicides, only
pendimethalin recorded significantly more grain yield
as compared to unweeded control. Similar results
were obtained by Singh et al. (2009) that under dry
seeding, higher grain yield was recorded with pre-
emergence application of pendimethalin 1.50 kg/ha.
The difference in yield might be due to differences in
application mode and efficacy of herbicides against
weed species.
Economics
Higher B:C ratio was obtained when bispyribac
was sprayed as follow-up application after pre-
emergence herbicides as compared with single
application of pre-emergence herbicides. The highest
net profit was realized from sequential application of
pendimethalin and bispyribac, followed by sequential
application of thiobencarb/butachlor/oxadiargyl and
bispyribac (Table 3). Net returns under weedy
situation were negative (loss), which revealed that
weed control in DSR is an important component.
Similarly, except pendimethalin, all other pre-
emergence herbicides resulted in negative returns.
REFERENCES
Chauhan BS and Johnson DE. 2011.Row spacing and weed
control timing affects yield of aerobic rice. Field Crops
Research 121: 226-231.
Kumar V and Ladha JK. 2011. Direct seeding of rice: recent
developments and future research needs. Advances in
Agronomy 111: 297-413.
Mahajan G, Chauhan BS and Johnson DE. 2009. Weed
management in aerobic rice in North-western Indo-Gangetic
Plains. Journal of Crop Improvement 23(4): 366-382.
Mahajan G and Timsina J. 2011 Effect of nitrogen rates and
weed control methods on weeds abundance and yield of
direct-seeded rice. Archives in Agronomy and Soil Science
57(3): 239-250.
Rao AN, Johnson DE, Sivaprasad B, Ladha JK and Mortimer
AM. 2007. Weed management in direct-seeded rice.
Advances in Agronomy 93: 153-255.
Singh B, Malik RK, Yadav A and Nandal DP. 2009. Herbicide
efficacy in seeded rice with different methods under wet
and dry conditions. Indian Journal of Weed Science
41(1&2): 37-40.
Singh M, Sriram CV, Hanji MB, Prabhukumar S and Kishor N.
2012. Crop-weed competition and weed management
studies in direct-seeded rice (Oryza sativa). Indian Journal
of Agronomy 57(1): 38-42.
Walia US, Bhullar MS, Nayyar S and Sidhu AS. 2009. Role of
seed rate and herbicides on growth and yield of direct dry-
seeded rice. Indian Journal of Weed Science 41(1&2): 33-36.
Walia US, Bhullar MS, Nayyar S and Walia SS. 2008. Control of
complex weed flora of dry-seeded rice (Oryza sativa L.)
with pre- and post-emergence herbicides. Indian Journal
of Weed Science 40(3 &4): 161-164.
Table 3. Effect of weed control treatments on crop growth, yield attributes, yield and economics of direct-seeded rice
(mean of two years)
Treatment Final plant
height (cm)
Crop dry matter
accumulation
(g/m2)
Number of
effective
tillers/m2
Number of
grains/
panicle
Grain
yield
(t/ha) B:C
Pendimethalin 0.75 kg/ha 68.9
776.3
147.5
69.2
2.35
0.09
Pendimethalin 0.75 fb bispyribac 0.025 kg/ha 84.5
1257.0
291.3
84.8
5.56
1.38
Butachlor 1.50 kg/ha 70.3
732.2
123.8
64.4
1.41
-0.33
Butachlor 1.50
fb
bispyribac 0.025 kg/ha 85.0
1203.2
243.9
79.3
5.22
1.28
Thiobencarb 1.50 kg/ha 66.7
777.1
141.3
65.3
1.48
-0.30
Thiobencarb 1.50
fb
bispyribac 0.025 kg/ha 87.0
1236.7
285.8
79.5
5.29
1.31
Anilofos 0.375 kg/ha 68.5
751.8
133.3
63.8
1.44
-0.31
Anilofos 0.375 fb bispyribac 0.025 kg/ha 86.7
1206.6
265.4
77.9
4.66
1.05
Pretilachlor 0.75 kg/ha 68.2
704.2
128.7
64.3
1.48
-0.30
Pretilachlor 0.75
fb
bispyribac 0.025 85.4
1166.7
272.5
79.1
4.65
1.02
Oxadiargyl 0.09 kg/ha 67.0
687.3
135.0
65.0
1.49
-0.29
Oxadiargyl0.09 fb bispyribac 0.025 kg/ha 85.5
1199.9
277.4
80.4
5.22
1.28
Pyrazosulfuron-ethyl 0.015 kg/ha 62.9
479.0
60.3
57.7
1.23
-0.42
Pyrazosulfuron-ethyl 0.015 fb
bispyribac 0.025 kg/ha 86.3
1170.7
235.4
79.4
4.44
0.94
Two hand weeding 87.6
1252.1
295.1
83.0
5.64
1.12
Unweeded 62.5
331.9
38.8
57.1
1.21
-0.31
LSD (P=0.05) 7.3
104.6
40.1
6.6
0.46
Bio-efficacy of different herbicides for weed control in direct-seeded rice
... Our results demonstrate that either pre-emergence or post-emergence herbicides alone was not able to control weed flora effectively: weed control efficiency was less than 60% in these treatments relative to combinations of pre-and post-emergence herbicides ( Table 3). The effectiveness of sequential application of herbicides in managing weed flora under mechanized rice establishment in both no-till and tilled experiments was reported by various studies (Jat et al., 2021;Kaur & Singh, 2015;Kumar & Ladha, 2011;Mahajan & Chauhan, 2015;Rao et al., 2007;Saha et al., 2021;M. Singh et al., 2015;V. ...
... Effective weed control was achieved at initial plant growth stages under pendimethalin, while weed control around tillering resulted from the bispyribac + pyrazosulfuron, which reduced weedcrop competition and promoted rice biomass and grain productivity. Higher rice grain yields with increased WCE have been reported elsewhere with sequential applications of pendimethalin followed by bispyribac alone or mixed with pyrazosulfuron (Kaur & Singh, 2015;Saha et al., 2021;V. Singh et al., 2016;Walia et al., 2012). ...
... Equations relating rice grain yield and WCE indicate that when WCE was less than 62% the rice grain yield was significantly reduced thus to achieve high rice grain yields it is critical that rice fields should be weed-free up to maximum tillering and panicle initiation, i.e. between transplanting and 40-55DAT, as these are the growth stages of rice critical to determining the ultimate yield. Strong positive relationships between rice grain yield and WCE and strong inverse relationships between rice grain yield and weed biomass have also been reported in many studies previously (Walia et al., 2012;Kaur & Singh, 2015;Mahajan & Chauhan, 2015;Hossain et al., 2020;Saha et al., 2021). ...
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Full-text available
  • Dec 2023
Weed management is an integral part of direct seeded rice technology owing to a very high weed infestation. Thus, in order to control the diverse weed flora using the most appropriate herbicide and devise the most effective date of sowing in the DSR, a two-year field experiment was conducted during the kharif season of 2019 and 2020 at Zonal Agricultural Research station Powarkheda, Narmadapuram, JNKVV Jabalpur. The field experiment was laid out in split plot design with three main plot treatments and five sub plot treatments and replicated thrice. The results revealed that late sowing of DSR on 20 th July and post emergence application of bispyribac sodium 25 g/ha had lesser weed density; weed dry weight and higher weed control efficiency (56.42% and 66.19 %) among all other treatments. However, plant growth characters, yield attributes and grain yield were higher with the early sowing of DSR on 20 th June and early post emergence application of bispyribac sodium 25g/ha. The early sowing on 20 th June along with the application of bispyribac sodium 25g/ha resulted in highest net monetary returns (83901 Rs/ha) which also increased the B:C ratio (3.1). Thus, it was concluded that the early sowing of direct seeded rice along with early post emergence application of bispyribac sodium can control the weeds and increase the grain yield and can prove to be a promising technology adopted by the farmers.
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... and Digitaria sanguinalis (L.) Scop., while fenoxaprop-ethyl 67 g ha −1 (as postemergence) is used to control Dactyloctenium aegyptium (L.) Willd., D. sanguinalis, Eleusine indica (L.) Gaertn. and Leptochloa chinensis (L.) Nees in DSR (Kaur & Singh, 2015;Bhullar et al., 2016). Further, continuous use of herbicides for control of annual grass weeds (For example, pendimethalin, bispyribac, fenoxaprop) in DSR has shifted the dominance to broad-leaf weeds and sedges, and from annual weeds to perennial weeds particularly C. rotundus in northwestern India (Walia, 2010). ...
Auxinic and sulfonyl urea herbicides for post-emergence control of sedges and broad-leaf weeds in direct-seeded rice
Article
Full-text available
  • Feb 2024
  • PHYTOPARASITICA
There is a shift of dominance from grasses to broad-leaf weeds and sedges in direct-seeded rice (DSR) due to the continuous use of grass herbicides. The uncontrolled growth of broad-leaf weeds and sedges in DSR throughout the entire crop season resulted in a 52–64% reduction in crop yield. Field studies were carried out to evaluate control of sedges and broad-leaf weeds with post-emergence application of 8, 12, 16 g ha⁻¹ of metsulfuron; 435, 580, 725 g ha⁻¹ of 2,4-dimethyl amine salt; 2, 4, 6 g ha⁻¹ of pre-mix of metsulfuron plus chlorimuron, and azimsulfuron 20 g ha⁻¹ in direct-seeded rice. The post-emergence application of azimsulfuron 20 g, metsulfuron plus chlorimuron 4 g and 2,4-D amine salt 725 g ha⁻¹ effectively reduced density and biomass of Cyperus rotundus L., C. iria L., Phyllanthus niruri L., Alternanthera philoxeroides (Mart.) Griseb., Mollugo nudicaulis Lam., Digera arvensis Forsk., Caesulia axillaris Roxb. and Ammannia baccifera L. Metsulfuron 16 g ha⁻¹ as post-emergence resulted in effective control (92.2–98.9%) of broad-leaf weeds but gave partial control (19.8–37.1%) of sedges. The maximum grain yield was recorded in weed-free treatment and it was statistically similar to grain yield obtained with post-emergence use of azimsulfuron 20 g or metsulfuron plus chlorimuron 4–6 g or 2,4-D amine salt 580–725 g ha⁻¹ herbicides. It is concluded that post-emergence use of 2,4-D amine salt 725 g or metsulfuron plus chlorimuron 4 g ha⁻¹ is efficient and economical herbicides for control of broad-leaf weeds and sedges in direct-seeded rice.
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... Fenoxaprop-pethyl 60 g/ha is primarily effectual against grassy weeds only and thus, had lowest weed control efficiency. Interaction among the irrigated agroecosystem and herbicidal treatment bispyribac sodium 25 g/ha achieved higher (89.5%) weed control efficacy (Kaur et al., 2015). The results are in corroboration with the findings of Narolia et al. (2014). ...
Influence of weed management practices on direct-seeded rice grown under rainfed and irrigated agroecosystems
Article
Full-text available
  • Jun 2023
Rice seedlings and weeds emerge concurrently in direct-seeded rice (DSR) production systems, while there is no flooding water to inhibit weed germination, emergence and development at crop emergence. Because of this, weeds are considered the biggest living barrier in DSR and significantly reduce yield. The purpose of the research was to devise an approach for management of weeds in the direct-seeded rice crop cultivated under various agroecosystems, while optimizing growth and production utilizing herbicides or herbicidal combinations. The impacts of several weed management techniques were assessed to determine the most efficient and cost-effective approach of managing weeds in DSR at the CoA, JNKVV, Jabalpur (MP) during 2019 rainy season under spilt plot design with 2 main plot treatments viz., rainfed agroecosystem, irrigated agroecosystem and 8 sub-plot treatments, i.e. different herbicide treatments with hand weeding and weedy check. Further growth parameters as well as yield attributes were documented. Conventional statistical techniques were used to evaluate the data. Bispyribac sodium at the dose of 25 g/ha efficiently controlled both narrow and broad leaved weeds under agroecosystems. Highest growth as well as yield parameters were recorded for irrigated agroecosystems compared to rainfed agroecosystems. The treatment with bispyribac sodium at the dose of 25 g/ha produced the greatest values for growth and yield indices as well as the maximum yield (3.68 t/ha), with the exception of manual weeding.
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... Herbicide degradation could be providing a carbon source for microbial development. Similar results were obtained by Kaur and Surjit, [12]. ...
Effect of Integrated Weed Management Practices on Microbial Population in Soil, Yield and Economics in Wet Direct Seeded Rice
Article
Full-text available
  • Mar 2023
An experiment had been conducted at the Agronomy Farm, Indira Gandhi Krishi Vishwavidyalaya, Raipur, (C.G.) in the kharif season of 2019, to determine the effects of integrated weed management practices on microbial population in soil, yield and economics in wet direct seeded rice. Pre-emergence herbicides (Oxadiargyl and Pretilachlor) were followed by post-emergence herbicide (Bispyribac-Na), mechanical and manual weeding. Plots treated with oxadiargyl performed better than pretilachlor. When Oxadiargyl was integrated with Hand Weeding (HW) at 35 days after sowing (DAS) gave results which were better than twice HW plot (T10). Oxadiargyl @ 70g/ha at 7-11 DAS fb HW at 30-35 DAS (T4) proved to be superior over all the treatments when yield and economics of wet direct seeded rice was concerned and was statistically at par with twice HW plot (T10) and oxadiargyl @ 70 g/ha at 7-11 DAS fb bispyribac-Na @ 25 g/ha at 30-35 DAS (T2). The unsprayed and two-hand weeding treatments had much lower levels of fungi, actinobacteria, and bacteria than the other weed control methods. The herbicidal treatments had much higher microbial populations at all stages of observation.
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... This might be due to less cost involved in chemical treatment per unit of yield obtained. These findings agreed with Kaur and Singh (2015) and Khare, Arti, and Jain, H.C. (1995). ...
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... Statistically it was at par with the application of pre-emergence herbicide pretilachlor @ 0.45 kg/ha fb HW on 40 DAS, butachlor @ 1.5 kg/ ha fb HW on 40 DAS and anilophos @ 0.45 kg/ha fb HW on 40 DAS. Kaur and Singh (2015) reported that application of bispyribac-Na 0.025 kg/ha as post-emergence after six pre-emergence herbicides (butachlor, thiobencarb, anilofos, pretilachlor, oxadiargyl and pyrazosulfuron-ethyl) produced lower weed density than these six pre-emergence herbicides applied alone. Ahmed and Chauhan (2014) reported that during aman and boro season both in Mymnesingh, Bangladesh, the lowest weed density (at 35 DAS) was observed in oxadiargyl @ 80 g/ha at 2 DAS fb ethoxysulfuron @ 18 g/ha at 21 DAS which was at par with oxadiargyl @ 80 g/ha at 2 DAS fb HW at 30 DAS. ...
Effect of integrated weed management practices on weed dynamics, growth and yield of wet direct seeded rice (Oryza sativa L.)
Thesis
Full-text available
  • Sep 2020
Effect of integrated weed management practices on weed dynamics, growth and yield of wet direct seeded rice (Oryza sativa L.)
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... Singh [220] evaluated three pre-emergence herbicides pendimethalin 1.0 kg/ha, butachlor 1.0 kg/ha, and oxadiargyl 0.09 kg/ha and found weed density after application of these herbicides were 10-13, 15, and 16-23 plants/ m 2 , respectively, compared to 51 plants/m 2 in weedy check at Taraori location. Kaur [105] evaluated seven pre-emergences (pendimethalin 0.75 g/ha, butachlor 1.50 kg/ha, thiobencarb 1.50 kg/ha, anilofos 0.375 kg/ha, pretilachlor 0.75 kg/ha, oxadiargyl 0.09 kg/ha, and pyrazosulfuron-ethyl 0.015 kg/ha) herbicides for their efficacy against weeds in DSR. ...
Agronomic and Environmental Determinants of Direct Seeded Rice in South Asia
Article
Full-text available
  • May 2022
Rice (Oryza sativa L.) is the staple food of more than 50% of the world’s population. Manual puddled transplanted rice (PTR) system is still the predominant method of rice establishment. However, due to declining water tables, increasing water scarcity, water, labor- and energy-intensive nature of PTR, high labor wages, adverse effects of puddling on soil health and succeeding crops, and high methane emissions, this production system is becoming less profitable. These factors trigger the need for an alternative crop establishment method. The direct-seeded rice (DSR) technique is gaining popularity because of its low input demand compared to PTR. It is done by sowing pre-germinated seeds in puddled soil (wet-DSR), standing water (water seeding), or dry seeding on a prepared seedbed (dry-DSR). DSR requires less water and labor (12–35%), reduces methane emissions (10–90%), improves soil physical properties, involves less drudgery and production cost (US$9–125 per hectare), and gives comparable yields. Upgraded short-duration and high-yielding varieties and efficient nutrient, weed, and resource management techniques encouraged the farmers to switch to DSR culture. However, several constraints are associated with this shift: more weeds, the emergence of weedy rice, herbicide resistance, nitrous oxide emissions, nutrient disorders, primarily N and micro-nutrients, and an increase in soil-borne pathogens lodging etc. These issues can be overcome if proper weed, water, and fertilizer management strategies are adopted. Techniques like stale bed technique, mulching, crop rotation, Sesbania co-culture, seed priming, pre-emergence and post-emergence spray, and a systematic weed monitoring program will help reduce weeds. Chemical to biotechnological methods like herbicide-resistant rice varieties and more competitive allelopathic varieties will be required for sustainable rice production. In addition, strategies like nitrification inhibitors and deep urea placement can be used to reduce N2O emissions. Developing site and soil-specific integrated packages will help in the broader adoption of DSR and reduce the environmental footprint of PTR. The present paper aims to identify the gaps and develop the best-bet agronomic practices and develop an integrated package of technologies for DSR, keeping in mind the advantages and constraints associated with DSR, and suggest some prospects. Eco-friendly, cost-effective DSR package offers sustainable rice production systems with fewer resources and low emissions. Graphical abstract
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Effect Of Sequential Application Of Pre And Post-Emergence Herbicides On Dynamics Of Weeds Associated With DSR System Andrice-Growth And Sustained Yield
Article
  • Sep 2023
The sustained rice yield plays an important role in the country’s GDP. The diverse weed flora is a potential biotic threat to the sustained yield in the DSR system. The crop faces severe competition the resources from its beginning (germination of crop seedlings) to the panicle initiation with the diverse weeds flora as it grows quickly in moist conditions, resulting in severe yield losses up to 65 per cent. Thus, an effective and economical weed control strategy in DSR is often required to overcome the losses. In such situations, sequential application of herbicides may provide broad-spectrum weed control in DSR. A field experiment was conducted on silty loam soils to assess the herbicidal effects on weed dynamics and growth & yield productivity of direct-seeded rainy (Kharif) rice at Agronomy Research Farm of Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya (U.P.) during the years, 2016 and 2017. The field trial was carried out in Randomized complete block design (RCBD) with three replications and twelve treatments. The treatments consisted of nine pre & post-emergent herbicide combinations along with three distinct controls, i.e. a) Hand weeding (at 20 & 40 DAS), b) Weed Free (weeding at every 15 days interval from seedling to the PI stage), and c) Weedy Check. The results of the field study revealed that the weed-free plots recorded the highest weed control efficiency, and they registered the least weeds density and dry weight of weeds associated with direct seeded rice fields. However, the application of herbicides, namely, pendimethalin (1000 g a.i. ha-1) as pre-emergent and Bispyribac-Na (1000 g a.i. ha-1) as post-emergent coupled with a hand weeding at 40 DAS provided the statistically comparable results to weed-free and is effectively controlled the diverse weed flora by 81.9-84.5 per cent in DSR system. And both the treatments gave significantly better growth (plant height, number of tillers, dry matter, LAI) and yields (grain and straw) of rice as compared to the weedy-check. Among the diverse weeds associated with the DSR fields, sedges were dominant as compared to broad leaves and grasses. The study also recorded the rice-grain yield reduction by 40.9 per cent due to the presence of diverse weed flora in weedy check plot as to weed-free plot.
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Weed Management in Aerobic Rice in Northwestern Indo-Gangetic Plains
Article
Full-text available
  • Oct 2009
  • J Crop Improv
Aerobic rice systems, wherein the crop is established via direct seeding in non-puddled, non-flooded fields, are among the most promising approaches for saving water and labor. However, aerobic systems are subject to much higher weed pressure than conventionally puddled transplanted rice (CPTR). Experiments were conducted for two years to develop effective and economical methods for managing weeds in aerobic rice grown by direct seeding rather than by conventional transplanting method. The proportion of mean grass-weed dry matter was 28.3% more in aerobic direct-seeded rice (ADSR) as compared to CPTR. Both weed density and dry weight were negatively correlated with rice grain yield. ADSR treatment produced yield similar to CPTR treatment when weeds were controlled effectively. Post-emergence application of bispyribac Na 25 g/ha and penoxsulam 25 g/ha could effectively control all the weeds in ADSR. Irrigation water productivity remained statistically the same in both ADSR and CPTR under the weed-free situation or when bispyribac Na herbicide was applied as post-emergence because of effective weed control in ADSR. The variation in net profitability between the ADSR and CPTR decreased with herbicide treatments, viz., Bispyribac Na, followed by penoxsulam and sequential application of pretilachlor and metsulfuron.
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Weed Management in Direct-Seeded Rice
Article
Full-text available
  • Jan 2007
  • ADV AGRON
Rice (Oryza sativa L.) is a principal source of food for more than half of the world population, especially in South and Southeast Asia and Latin America. Elsewhere, it represents a high‐value commodity crop. Change in the method of crop establishment from traditional manual transplanting of seedlings to direct‐seeding has occurred in many Asian countries in the last two decades in response to rising production costs, especially for labor and water. Direct‐seeding of rice (DSR) may involve sowing pregerminated seed onto a puddled soil surface (wet‐seeding) or into shallow standing water (waterseeding), or dry seed into a prepared seedbed (dry‐seeding). In Europe, Australia, and the United States, direct‐seeding is highly mechanized. The risk of crop yield loss due to competition from weeds by all seeding methods is higher than for transplanted rice because of the absence of the size differential between the crop and weeds and the suppressive eVect of standing water on weed growth at crop establishment. Of 1800 species reported as weeds of rice, those of the Cyperaceae and Poaceae are predominant. The adoption of direct‐seeding has resulted in a change in the relative abundance of weed species in rice crops. In particular, Echinochloa spp., Ischaemum rugosum, Cyperus diVormis, and Fimbristylis miliacea are widely adapted to conditions of DSR. Species exhibit variability in germination and establishment response to the water regime postsowing, which is a major factor in interspecifically selecting constituents of the weed flora. The relatively rapid emergence of ‘‘weedy’’ (red) rice, rice phenotypically similar to cultivars but exhibiting undesirable agronomic traits, has been observed in several Asian countries practicing DSR, and this poses a severe threat to the sustainability of the production system. Stale seedbeds, tillage practices for land leveling, choice of competitive rice cultivars, mechanical weeders, herbicides, and associated water management are component technologies essential to the control of weeds in DSR. Herbicides in particular are an important tool of weed management, but hand weeding is either partially or extensively practiced in countries of Asia, Africa, and Latin America. Though yet to be globally commercialized, transgenic rice varieties engineered for herbicide resistance are a potential means of weed control. The release of herbicide‐resistant rice for red rice control in the United States has indicated the need to critically examine mitigation methods for the control of gene flow. Integrating preventive and interventional methods of weed control remains essential in managing weed communities in DSR, both to prohibit the evolution of herbicide resistance and to maximize the relative contributions of individual components where herbicides are not widely used. There remains a need to further develop understanding of the mechanisms and dynamics of rice weed competition and of the community dynamics of weed populations in DSR to underpin sustainable weed management practices.
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Effect of nitrogen rates and weed control methods on weeds abundance and yield of direct-seeded rice
Article
Full-text available
  • May 2011
  • Arch Agron Soil Sci
Field experiments were conducted at the Punjab Agricultural University, Ludhiana, India, during 2007–2008 to examine if nitrogen (N) rates and weed management practices using herbicides in combination with hand-weeding (HW) can improve crop competitiveness against weeds, and increase the yield, water productivity and profitability of direct-seeded rice (DSR). Increasing N application rate up to 150 kg ha−1 caused significant improvement in grain yield when the weeds were well controlled either by Pendimethalin + Bispyribac Na or by Pendimethalin + Bispyribac Na + 1 HW, respectively; however, under poor weed control condition (Pendimethalin + 1 HW), it resulted in a drastic reduction in yield. The highest net returns ($1083) and water productivity (0.60 kg m−3) were observed for N application of 150 kg ha−1 and weeds were controlled with Pendimethain + Bispyribac Na + 1 HW. We suggest that Pendimethalin + Bispyribac Na + 1 HW is the best integrated weed management strategy to control weeds, and to increase yield, water productivity, and profitability. We propose that the simulation modelling tool be utilized in future for evaluating options for improving sustainable N and weed management policies especially when crop, weeds, soil, weather and management data are available for calibration and validation of appropriate and existing simulation model of rice.
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Crop-weed competition and weed management studies in direct seeded rice (Oryza sativa)
Article
  • Mar 2012
Field experiments were conducted during 2006-07 and 2007-08 at Krishi Vigyan Kendra, Madurai, Tamil Nadu under the Zonal Project Directorate, Bangalore to study the critical period of crop weed competition and develop an integrated and effective weed control practices, combining chemical, manual and mechanical methods, for direct seeded rice (Oryza sativa L.). It was found that first 40 days after sowing was the most critical period for crop weed competition. The crop grown under weed free condition for 40 days after sowing gave the maximum grain yield (2.93 t/ha). Hand-weeding followed by foliar application of urea was significantly superior to rest of the treatments and gave maximum grain (4.33 t/ha) and straw yields (8.17 t/ha). Post-emergence application of propanil @ 3.8 kg/ha at 20 days after sowing and soil application of urea was most effective in increasing the crop yield and minimizing the crop weed competition. Highest weed control efficiency of 88.1% was recorded in crop given propanil @ 3.8 kg/ha + hand weeding within rows and hoeing at 40 DAS and it closely followed by the application of butachlor @ 2.5 kg/ha + hand weeding within rows and hoeing at 40 DAS. In the integrated approach, postemergence application of propanil @ 3.8 kg/ha at 20 days after sowing followed by hoeing between the rows and hand weeding within rows at 40 days after sowing minimized crop weed competition, increased uptake of N, P and K by crop and maximized grain yield and economical returns significantly.
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Row spacing and weed control timing affect yield of aerobic rice
Article
  • Mar 2011
  • Fuel Energ Abstr
Field experiments were conducted during the wet season of 2009 and dry season of 2010 to determine the effects of row spacing and timing of weed control on weed growth and yield of aerobic rice. Ten weed management treatments were used to identify critical periods of weed competition with aerobic rice grown in three different row spacings (15-cm, 30-cm, and as paired rows 10–20–10-cm). Dominant weed species during both growing seasons were Rottboellia cochinchinensis, Digitaria ciliaris, Echinochloa colona, and Eleusine indica. Rice grown in 30-cm rows had greater weed biomass and less grain yield than in 15-cm and 10–20–10-cm rows; weed growth and grain yields were similar between 15-cm and 10–20–10-cm rows. Rice yields in the wet season ranged from 170kgha−1 where weeds were not controlled throughout the crop duration to 2940kgha−1 in weed-free treatment, indicating a 94% yield loss with uncontrolled weed growth. Similarly in the dry season, plots with no weed control (140kgha−1) compared to weed-free plots (3640kgha−1) indicate a 96% yield loss with no weed control. Gompertz and logistic equations were fitted to yield data resulting from increasing durations of weed control and weed interference, respectively. Critical periods for weed control in the wet season, to obtain 95% of a weed-free yield, were estimated as between 18 and 52 days after sowing (DAS) for crops in rows at 15-cm, 20–51DAS at 10–20–10-cm, and 15–58DAS at 30-cm. These intervals in the dry season were 17–56DAS for crops in rows at 15-cm and 17–60DAS at 10–20–10-cm and 15–64DAS at 30-cm. Durations of the critical periods in the wet season were 31 days at 10–20–10-cm, 34 days at 15-cm and 43 days at 30-cm, while in the dry season, these were 43 days at 10–20–10-cm, 39 days at 15-cm and 49 days at 30-cm. In both seasons, crops in the wider spacing (30-cm) were vulnerable to weed competition for the longest period. The information gained from this study suggests that the aerobic rice yields better in 15-cm rows and 10–20–10-cm arrangements than in 30-cm rows and there is very little benefit of weed control beyond 8 weeks after sowing.
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Direct Seeding of Rice. Recent Developments and Future Research Needs
Article
  • Jan 2011
  • ADV AGRON
Rice (Oryza sativa L.), a staple food for more than half of the world population, is commonly grown by transplanting seedlings into puddled soil (wet tillage) in Asia. This production system is labor-, water-, and energy-intensive and is becoming less profitable as these resources are becoming increasingly scarce. It also deteriorates the physical properties of soil, adversely affects the performance of succeeding upland crops, and contributes to methane emissions. These factors demand a major shift from puddled transplanting to direct seeding of rice (DSR) in irrigated rice ecosystems. Direct seeding (especially wet seeding) is widely adopted in some and is spreading to other Asian countries. However, combining dry seeding (Dry-DSR) with zero/reduced tillage (e.g., conservation agriculture (CA)) is gaining momentum as a pathway to address rising water and labor scarcity, and to enhance system sustainability. Published studies show various benefits from direct seeding compared with puddled transplanting, which typically include (1) similar yields; (2) savings in irrigation water, labor, and production costs; (3) higher net economic returns; and (4) a reduction in methane emissions. Despite these benefits, the yields have been variable in some regions, especially with dry seeding combined with reduced/zero tillage due to (1) uneven and poor crop stand, (2) poor weed control, (3) higher spikelet sterility, (4) crop lodging, and (5) poor knowledge of water and nutrient management. In addition, rice varieties currently used for DSR are primarily selected and bred for puddled transplanted rice. Risks associated with a shift from puddled transplanting to DSR include (1) a shift toward hard-to-control weed flora, (2) development of herbicide resistance in weeds, (3) evolution of weedy rice, (4) increases in soil-borne pathogens such as nematodes, (5) higher emissions of nitrous oxide—a potent greenhouse gas , and (6) nutrient disorders, especially N and micronutrients. The objectives of this chapter are to review (1) drivers of the shift from puddled transplanting to DSR; (2) overall crop performance, including resource-use efficiencies of DSR; and (3) lessons from countries where DSR has already been widely adopted. Based on the existing evidence, we present an integrated package of technologies for Dry-DSR, including the identification of rice traits associated with the attainment of optimum grain yield with Dry-DSR.
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Herbicide efficacy in seeded rice with different methods under wet and dry conditions
  • Jan 2009
  • 37-40
  • B Singh
  • R K Malik
  • Yadav A Nandal
Singh B, Malik RK, Yadav A and Nandal DP. 2009. Herbicide efficacy in seeded rice with different methods under wet and dry conditions. Indian Journal of Weed Science 41 (1& 2): 37-40.