Navneet Aggarwal; et al Mash paper

Full text

www.IndianJournals.com
Members Copy, Not for Commercial Sale
Downloaded From IP - 202.164.55.185 on dated 1-Dec-2014
Indian Journal of Agronomy 59 (3): 421__426 (September 2014) Research Paper
Effect of post-emergence application of imazethapyr on symbiotic activities,
growth and yield of blackgram (Vigna mungo) cultivars and its efficacy
against weeds
NAVNEET AGGARWAL1, GURIQBAL SINGH2, HARI RAM3 AND VEENA KHANNA4
Punjab Agricultural University, Ludhiana, Punjab 141 004
Received : January 2014; Revised accepted : May 2014
ABSTRACT
A field experiment was conducted during the rainy (
kharif
) season of 2008 and 2009 at Ludhiana, Punjab to
study tolerance of different blackgram [
Vigna mungo
(L.) Hepper] cultivars to post-emergence application of
imazethapyr and its efficacy on weeds. The exper iment was laid out with 8 weed-control treatments, viz.
imazethapyr at 3 application rates (50, 75 and 100 g/ha) sprayed at 15 and 25 days after sowing (DAS), 2 hand-
weedings (20 and 40 DAS) and unweeded control and 2 blackgram cultivars (‘Mash 114’ and ‘Mash 338’). Both
the cultivars showed good degree of tolerance to imazethapyr sprayed at different doses and at different times.
Post-emergence application of imazethapyr had no adverse effect on shoot dry weight as well as root dry weight of
blackgram cultivars. Number of nodules, dry weight of nodules and leghaemoglobin content were the highest in
imazethapyr 100 g/ha sprayed at 15 DAS, being statistically at par with 2 hand-weedings (20 and 40 DAS).
imazethapyr application at 75 and 100 g/ha at 15 DAS resulted in effective control of weeds which was comparable
to that of 2 hand-weedings. Application of imazethapyr at 100 g/ha at 15 DAS resulted in 62.0% higher grain yield
over the unweeded control. Imazethapyr at 100 g/ha at 15 DAS also recorded the highest gross and net returns of
41,400 and 29,800 respectively, which was closely followed by imazethapyr at 100 g/ha sprayed at 25 DAS
and 2 hand-weedings.
Key words :
Blackgram, Cultivars, Imazethapyr, Tolerance, Weed-control efficiency
1Corresponding author Email: navneetpulsespau@yahoo.com
1Assistant Agronomist; 2Senior Agronomist (Pulses); 3Agronomist
(Wheat); 4Senior Microbiologist (Pulses); Department of Plant
Breeding & Genetics, Punjab Agricultural University, Ludhiana 141
004
Blackgram is usually accompanied by luxuriant weed
growth during the rainy (kharif) season owing to abundant
rainfall received during monsoons leading to serious crop
losses. The crop is not a very good competitor against
weeds (Choudhary et al., 2012) and therefore, weed-con-
trol initiatives are essential to ensure proper crop growth,
particularly in the early growth period. Depending on the
nature, density and period of occurrence, weeds can cause
losses of grain yield of blackgram varying from 41.6 to
64.1% (Chand et al., 2004; Rathi et al., 2004; Singh,
2011). Presently, only pre-emergence herbicides are avail-
able which are recommended to manage weeds in kharif
blackgram. Sometimes early rains soon after the sowing
make it almost impossible to spray pre-emergence herbi-
cides on this crop. Further, many a times weeds emerge at
a later stage which can be controlled by hand-weedings
(Chand et al., 2004). Also, hand-weeding is labour-inten-
sive, time-consuming, costly and tedious process. The
critical period of crop–weed competition in blackgram
usually falls between 15 and 45 days after sowing (DAS)
(Vivek et al., 2008) and many a times, labour is not avail-
able particularly when critical period of crop–weed com-
petition sets in. Moreover, monsoon rains make it impos-
sible to go for hand- weeding due to wet field conditions.
Under these situations, use of post-emergence herbicides
offers an alternative for effective weed management in
blackgram.
Imazethapyr, a broad-spectrum herbicide, has soil and
foliar activity that allows flexibility in its application tim-
ing and has low mammalian toxicity (Tan et al., 2005).
Imazethapyr applied as post-emergence at 50 to 75 g/ha
shows season-long control of many weeds without injuring
soybean (Ram et al., 2013). In blackgram, Nandan et al.
(2011) reported that post-emergence application of
imazethapyr at 25 g/ha had no adverse effects on rainfed
blackgram growth characters and resulted in statistically
similar grain yield to that of 2 hand-weedings (20 and 40
days after sowing).

www.IndianJournals.com
Members Copy, Not for Commercial Sale
Downloaded From IP - 202.164.55.185 on dated 1-Dec-2014
422 AGGARWAL ET AL. [Vol. 59, No. 3
Crop injury due to herbicides, if any, may vary with the
herbicide, application dose, application timing and varietal
tolerance. Tolerance of blackgram cultivars to the
imidazolinone class of herbicides would be a desirable
agronomic trait and little information is available on this
aspect particularly under irrigated conditions. Hence
present study conducted was to determine the tolerance of
different blackgram cultivars to imazethapyr and to find
out the efficacy of post-emergence application of
imazethapyr at different doses and timings against weeds.
MATERIALS AND METHODS
A field experiment was conducted at the Punjab Agri-
cultural University, Ludhiana (30o56´ N and 75o52´ E, 247
m above mean sea level), Punjab, during 2008 and 2009
under irrigated conditions. The experiment comprised 8
weed-control treatments, viz. imazethapyr at 3 doses, i.e.
50, 75 and 100 g/ha sprayed at 15 and 25 days after sow-
ing (DAS), 2 hand-weedings (20 and 40 DAS) and
unweeded control in the main plot; and 2 blackgram cul-
tivars (‘Mash 114’ and ‘Mash 338’) in the subplots. The
experiment was conducted in split-plot design. The soil
was loamy sand (Typic Ustochrepts). The top 0–15 cm
layer of the soil profile was neutral in pH (7.5, 1 : 2 soil :
water ratio), with 0.12 dS/m electrical conductivity, low in
KMnO4-oxidizable N (184.3 kg/ha) and Walkley and
Black organic carbon (0.29%), medium in Olsen- P (13.6
kg/ha) and 1 N NH4OAc-extractable K (143.8 kg/ha). The
meteorological data recorded at meteorological observa-
tory of the University indicated that rainfall received dur-
ing the crop season was 574.7 and 705.4 mm in 2008 and
2009 respectively. The crop experienced mean weekly
maximum temperatures ranging from 29.5 to 34.8oC and
30.3 to 36.4oC during 2008 and 2009 respectively
whereas, the mean weekly minimum temperature ranged
from 16.7 to 28.4oC and 11.3 to 28.7oC during 2008 and
2009, respectively.
Seedbed was prepared by 2 cultivations followed by
double planking. The sowing was done at a depth of 4–6
cm in moist soil in rows 30 cm apart with the help of
single row hand drill using seed rate of 20 kg/ha for both
the cultivars. Before seeding, the seeds were treated with
Captan at 3 g/kg seed to prevent seed-borne diseases. The
experiments were sown on 14 July and 5 July in 2008 and
2009, respectively. The crop was fertilized with 12.5 kg N
and 25 kg P2O5/ha. Nitrogen and phosphorus were applied
through urea (46% N) and single superphosphate (16%
P2O5) respectively. Total quantity of all the fertilizers was
applied at sowing. The spray of herbicide was done with
the help of knap-sack sprayer fitted with flat-fan nozzle
using spray volume of 375 litres/ha. In hand-weeding
treatment, weeding was done with a hand-hoe. Two irriga-
tions were applied as per the requirement of the crop in
both the seasons. Thiodan 35 EC (endosulfan) was
sprayed @ 2.5 litres/ha during both the years to control
pod-borer. The crop was harvested manually on 22 Octo-
ber and 10 October in 2008 and 2009 respectively. The
crop was sun-dried for 3 days and manual threshing was
done separately from each experimental unit.
Data on number of nodules with respect to native rhizo-
bia and nodule dry weight were recorded at 35 DAS i.e. at
flower-initiation stage. Five plants from each plot were
uprooted carefully, their roots were washed and nodules
were detached and counted. Dry weight of nodules, shoots
and roots was determined after drying to constant weight
at 65oC. The leghaemoglobin content was determined by
the method given by Wilson and Reisenauer (1963). The
data on dry weight of weeds were recorded on whole-plot
basis at harvesting during both the years. The weeds were
cut at the stem base near the soil surface, put in the paper
bags after sun drying, then dried in an oven at 60oC for 72
hours and biomass was recorded. At maturity, observations
on plant height, branches/plant and pods/plant were taken
from 5 random plants/plot. Pods were collected from 5
plants in each plot and threshed manually to record seeds/
pod. A 100-seed sample was collected from each plot for
recording 100-seed weight. Biological yield and grain
yield were recorded on a plot basis and harvest index was
calculated. Weed-control efficiency (WCE) was calculated
as:
(Dry weight of weeds in weedy check – Dry weight of
weeds in treatment)
WCE = × 100
Dry weight of weeds in weedy check
Gross returns were calculated by taking the sale price
of blackgram as 36 per kg.
Net returns ( /ha) were calculated as: Net returns =
Gross returns - cost of cultivation including the cost of
individual treatments. Benefit: cost ratio was calculated
after dividing net returns with the cost of cultivation.
All the data were subjected to analysis of variance
(ANOVA) as per the standard procedures. The comparison
of treatment means was made by critical difference (CD)
at P ≤ 0.05.
RESULTS AND DISCUSSION
Blackgram tolerance to herbicide
No visual adverse effects in terms of yellowing, leaf
injury or necrosis or change in morphology was observed
on any blackgram cultivar due to post-emergence applica-
tion of imazethapyr at different doses and timings. The
visual observations on growth showed that both the culti-
vars of blackgram revealed good degree of tolerance to
imazethapyr. Nandan et al. (2011) also reported that post-

www.IndianJournals.com
Members Copy, Not for Commercial Sale
Downloaded From IP - 202.164.55.185 on dated 1-Dec-2014
September 2014] BLACKGRAM RESPONSE TO IMAZETHAPYR 423
emergence application of imazethapyr at 25 g/ha at 15–20
DAS was safe to the blackgram. Post-emergence applica-
tion of imazethapyr had no adverse effect on shoot as well
as root dry weight/plant when recorded at flower-initiation
stage (Table 1). imazethapyr 100 g/ha at 15 DAS recorded
the highest shoot and root dry weight which was statisti-
cally at par with 2 hand-weedings (20 and 40 DAS) and
indicated that application of imazethapyr was safe to the
crop even at the highest dose of 100 g/ha. Reduction in dry
weight of shoots and roots with decreasing dose of
imazethapyr could be attributed to increasing dry matter of
weeds, which led to more competition with the crop and
thereby decreased its growth.
Symbiotic activities
Nodulation was significantly influenced by different
weed-control treatments and blackgram cultivars (Table
1). Number of nodules was the highest in imazethapyr 100
g/ha 15 DAS, being statistically at par with imazethapyr
75 g/ha 15 DAS and 2 hand-weedings (20 and 40 DAS)
but was significantly better than all other weed-control
treatments. Imazethapyr 100 g/ha 15 DAS resulted in the
highest dry weight of nodules, which was significantly
higher than imazethapyr at 50 g/ha 15 and 25 DAS and
unweeded control, but was statistically at par with all other
weed-control treatments. Better growth attributes caused
more accumulation and translocation of photosynthates by
the crop, which resulted in more number and dry weight of
nodules (Choudhary et al., 2012). Application of
imazethapyr 100 g/ha 15 DAS recorded the highest
leghaemoglobin content which was statistically similar as
in case of imazethapyr 75 g/ha 15 DAS, imazethapyr 100
g/ha 25 DAS and 2 hand-weedings (20 and 40 DAS) but
was significantly higher than all other weed-control treat-
ments. Goud et al. (2013) also reported that imazethapyr
@ 75 g/ha had no adverse effect on nodule number and
biomass relative to weedy check and hand-weeding in
chickpea. The absence of any adverse effect of
imazethapyr on nodulation may also be attributed to the
fact that imazethapyr has been reported to positively affect
nodule initiation and not nodule development (Royuela et
al., 2000). Among cultivars, ‘Mash 114’ produced signifi-
cantly more nodules/plant, nodule dry weight and
leghaemoglobin content than ‘Mash 338’. It might have
happened due to varietal variation for symbiotic charac-
ters.
Growth and yield attributes
Different weed-management practices improved plant
growth and yield attributes of blackgram over the
unweeded control (Table 2). Imazethapyr at 100 g/ha at 15
DAS resulted in the highest plant height, being statistically
at par with all other weed-control treatments except
imazethapyr 50 g/ha at 15 and 25 DAS and unweeded
control. All the weed-management treatments resulted in
statistically similar number of branches/plant. This showed
Table 1. Root and shoot dry weight, nodulation and leghaemoglobin content in blackgram as influenced by post-emergence herbicidal treat-
ments and cultivars recorded at flower-initiation stage (35 DAS) (pooled data of 2 years)
Treatment Root dry Shoot dry Nodules/ Nodules dry Leghaemoglobin
weight/plant weight/plant plant weight/plant content (mg/g
(mg) (g) (mg) fresh weight of
nodules)
Weed control treatment
Imazethapyr 50 g/ha 15 DAS 128.8 4.76 21.3 20.7 0.386
Imazethapyr 75 g/ha 15 DAS 133.0 5.38 23.7 21.7 0.423
Imazethapyr 100 g/ha 15 DAS 139.2 5.73 26.0 24.5 0.430
Imazethapyr 50 g/ha 25 DAS 118.4 4.57 18.9 19.2 0.389
Imazethapyr 75 g/ha 25 DAS 126.3 4.96 21.4 21.5 0.406
Imazethapyr 100 g/ha 25 DAS 134.1 5.43 22.7 22.4 0.415
2 hand-weedings (20 and 40 DAS) 134.7 5.33 23.3 21.9 0.429
Unweeded control 114.3 4.02 17.7 16.5 0.300
SEm+ 5.1 0.17 1.1 1.3 0.007
CD (P=0.05) 12.6 0.41 2.8 3.2 0.016
Cultivars
‘Mash 114’ 131.3 5.17 23.2 22.7 0.439
‘Mash 338’ 125.9 4.86 20.5 19.4 0.365
SEm± 2.0 0.10 0.8 0.6 0.04
CD (P=0.05) 5.1 0.24 1.8 1.4 0.09
DAS: Days after sowing

www.IndianJournals.com
Members Copy, Not for Commercial Sale
Downloaded From IP - 202.164.55.185 on dated 1-Dec-2014
424 AGGARWAL ET AL. [Vol. 59, No. 3
that application of imazethapyr at different doses and at
different times had no adverse effect on growth of
blackgram. Further, imazethapyr at 100 g/ha at 15 DAS
resulted in the maximum pods/plant which were statisti-
cally at par with 2 hand-weedings and were significantly
higher than all other weed-control treatments (Table 2).
Ram and Singh (2011) also reported that post-emergence
application of imazethapyr 75 g/ha at 20–25 DAS resulted
in significantly higher pods/plant than weedy check but
were at par with 2 hand-weedings at 20 and 40 DAS in
soybean. All the weed control treatments recorded signifi-
cantly more seeds/pod and 100-seed weight over the
unweeded control.
Both the cultivars of blackgram, viz. ‘Mash 114’ and
‘Mash 338’ recorded statistically similar plant height,
branches/plant, pods/plant, seeds/pod and 100-seed
weight.
Biological yield, grain yield and harvest index
Different weed-control treatments had a significant in-
fluence on biological yield and grain yield (Table 3). High-
est biological yield was obtained with imazethapyr 100 g/
ha applied at 15 DAS which was statistically at par with
all other weed-control treatments except with imazethapyr
at 50 and 75 g/ha sprayed at 25 DAS and unweeded con-
trol.
Application of imazethapyr 100 g/ha at 15 DAS and 2
hand-weedings gave the highest grain yield of blackgram
which was at par with imazethapyr 75 g/ha applied at 15
DAS and imazethapyr 100 g/ha applied at 25 DAS but
significantly higher than all other weed-control treatments
and unweeded control. Application of imazethapyr 100 g/
ha at 15 DAS resulted in 62.0% higher grain yield over the
unweeded control. Nirala et al. (2012) also reported that
post-emergence application of imazethapyr at 25 g/ha sig-
nificantly increased yield of blackgram over unweeded
control. The higher grain yield in these treatments might
be owing to better weed control in these treatments which
ultimately increased the yield attributes. The highest har-
vest index was recorded under 2 hand-weedings, which
was closely followed by imazethapyr 75 and 100 g/ha ap-
plied at 15 DAS and imazethapyr 100 g/ha applied at 25
DAS.
The data on biological yield and grain yield showed
non-significant differences in the both blackgram cultivars
(Table 3). Both the cultivars also registered almost similar
harvest index.
Weed biomass and weed-control efficiency
The major weed flora in the experimental fields in-
cluded Dactyloctenum aegyptiacum (crowfoot grass),
Cyperus rotundus (purple nutsedge), Cynodon dactylon
(bermuda grass), Commelina benghalensis (benghal day-
flower), Eragrostis pilosa (soft love grass), Trianthema
portulacastrum (horse purslane), Digitaria arvensis (wild
crab grass) etc. during the 2 years.
The minimum dry weight of weeds was recorded under
2 hand-weedings (20 and 40 DAS), which was signifi-
cantly lower than all other weed-control treatments at har-
vesting (Table 3). Further, application of imazethapyr 50,
75 and 100 g/ha at 15 and 25 DAS resulted in significantly
lower weed dry weight than the unweeded control. Among
Table 2. Growth and yield attributes of blackgram as influenced by different post-emergence herbicidal treatments and cultivars (pooled data
of 2 years)
Treatment Plant height Branches/ Pods/ Seeds/ 100-seed
(cm) plant plant pod weight (g)
Weed control treatment
Imazethapyr 50 g/ha 15 DAS 55.4 5.38 24.6 6.24 3.17
Imazethapyr 75 g/ha 15 DAS 63.2 5.53 28.5 6.28 3.06
Imazethapyr 100 g/ha 15 DAS 66.1 6.03 31.7 6.08 3.11
Imazethapyr 50 g/ha 25 DAS 55.5 5.28 24.6 6.30 3.09
Imazethapyr 75 g/ha 25 DAS 61.8 5.77 26.1 6.08 3.11
Imazethapyr 100 g/ha 25 DAS 64.5 6.03 28.4 6.30 3.00
2 hand-weedings (20 and 40 DAS) 65.8 6.30 31.6 6.15 3.16
Unweeded control 53.9 5.50 21.4 5.55 2.89
SEm+ 3.3 0.35 0.8 0.17 0.06
CD (P=0.05) 7.9 NS 1.9 0.41 0.14
Cultivars
‘Mash 114’ 60.8 5.65 27.6 6.15 2.94
‘Mash 338’ 60.7 5.81 26.6 6.10 3.20
SEm± 0.4 0.08 0.7 0.03 0.14
CD (P=0.05) NS NS NS NS NS

www.IndianJournals.com
Members Copy, Not for Commercial Sale
Downloaded From IP - 202.164.55.185 on dated 1-Dec-2014
September 2014] BLACKGRAM RESPONSE TO IMAZETHAPYR 425
the different herbicide treatments, lowest weed dry weight
was recorded in imazethapyr at 100 g/ha applied at 15
DAS and was statistically at par with imazethapyr at 75 g/
ha at 15 DAS but significantly lower than imazethapyr at
50 g/ha at 15 DAS and imazethapyr 50, 75 and 100 g/ha
at 25 DAS. Ram et al. (2013) and Nirala et al. (2012) also
observed that post-emergence application of imazethapyr
can be used effectively in reducing the weed intensity and
dry-matter production by weeds in soybean and
blackgram. Similarly, Ram and Singh (2011) also reported
that in soybean, application of imazethapyr at 75 g/ha at
20-25 DAS resulted in the minimum weed biomass which
was significantly lower than weedy check.
Weed-control efficiency was the highest under 2 hand-
weedings treatment, followed by imazethapyr 100 g/ha
and then 75 g/ha sprayed 15 DAS (Table 3). Greater re-
duction in weed biomass might have increased the weed-
control efficiency under these treatments. Weed-control
efficiency was the lowest in imazethapyr 50 g/ha at 25
DAS due to poor weed-control at lower dose. Nandan et
al. (2011) also reported highest weed-control efficiency in
blackgram with imazethapyr 25 g/ha at 15–20 DAS.
Blackgram cultivar ‘Mash 338’ showed significant su-
periority in its weed suppression potential to ‘Mash 114’
when recorded at harvesting.
Regression analysis
During regression analysis, the equations Y = –0.002 X
+ 1.425 (Fig. 1a) and Y = –0.001 X + 1.090 (Fig 1b) were
found to be fit for the grain yield and dry-matter of weeds Fig. 1. Effect of dry matter of weeds on grain yield of blackgram in
2008 (a) and in 2009 (b)
Table 3. Biological yield, grain yield, harvest index, economics of blackgram and weed growth as influenced by post-emergence herbicidal
treatments and cultivars (pooled data of 2 years)
Treatment Biological Grain Harvest Dry matter Weed Gross Net Benefit:
yield yield index of weeds control returns returns cost ratio
(t/ha) (t/ha) (g/m2) efficiency (× 103 /ha)(× 103/ha)
(%)
Weed control treatment
Imazethapyr 50 g/ha 15 DAS 4.45 0.92 0.22 123 54.1 33.2 22.3 2.04
Imazethapyr 75 g/ha 15 DAS 4.51 1.07 0.25 84 68.6 38.3 27.0 2.39
Imazethapyr 100 g/ha 15 DAS 4.87 1.15 0.25 73 72.6 41.4 29.8 2.57
Imazethapyr 50 g/ha 25 DAS 3.98 0.82 0.21 161 39.7 29.5 18.6 1.69
Imazethapyr 75 g/ha 25 DAS 4.18 0.98 0.24 126 52.7 35.1 23.9 2.14
Imazethapyr 100 g/ha 25 DAS 4.46 1.08 0.25 119 55.5 38.7 27.1 2.34
2 hand-weedings (20 and 40 DAS) 4.56 1.15 0.26 40 85.1 41.4 26.9 1.86
Unweeded control 3.34 0.71 0.22 267 25.6 15.6 1.56
SEm+ 0.26 0.07 11 2.1 1.7 0.18
CD (P=0.05) 0.66 0.15 25 5.2 4.2 0.45
Cultivars
‘Mash 114’ 4.23 1.00 0.24 117 36.0 24.5 2.13
‘Mash 338’ 4.35 0.98 0.23 131 35.3 23.8 2.07
SEm+ 0.08 0.01 5 0.3 0.4 0.02
CD (P=0.05) NS NS 13 NS NS NS
for 2008 and 2009 respectively, where Y is grain yield and
X is weed biomass. These models predicted the grain yield
very close to the actual grain yield recorded in the experi-
ment. Correlation between grain yield of blackgram and
(b)
(a)

www.IndianJournals.com
Members Copy, Not for Commercial Sale
Downloaded From IP - 202.164.55.185 on dated 1-Dec-2014
426 AGGARWAL ET AL. [Vol. 59, No. 3
weed biomass was –0.91 and R2 = 0.83** in 2008,
whereas the corresponding values were –0.93 and 0.86**
in 2009, which indicated that, as the weed biomass in-
creased, the grain yield of blackgram was reduced.
Economics
Application of imazethapyr 100 g/ha at 15 DAS gave
the highest gross and net returns, closely followed by
imazethapyr at 100 g/ha applied at 25 DAS and 2 hand-
weedings (Table 3). Ram et al. (2013) also reported higher
gross and net returns with imazethapyr 75 and 100 g/ha
than 50 g/ha in soybean. Application of imazethapyr at
100 g/ha at 15 DAS realized maximum benefit: cost ratio,
closely followed by imazethapyr 75 g/ha at 15 DAS. This
might be owing to the better weed-control efficiency un-
der these treatments which resulted in higher grain yield
and higher returns. Although gross returns under 2 hand-
weedings were comparable to those under imazethapyr at
75 and 100 g/ha applied at 15 DAS but higher cost in-
curred on 2 hand-weedings, resulting in decreased net re-
turns and benefit: cost ratio. Among different weed-control
treatments, poor weed control in imazethapyr at 50 g/ha at
25 DAS resulted in the lowest grain yield and thereby re-
corded least benefit: cost ratio.
It was concluded from the 2 years study that post-emer-
gence application of imazethapyr at 50, 75 and 100 g/ha at
15 and 25 DAS was safe to both the blackgram cultivars,
viz. ‘Mash 114’ and ‘Mash 338’. Further, application of
imazethapyr at 75 g/ha at 15 DAS was most effective for
the control of weeds and resulted in higher grain yields
and net returns.
REFERENCES
Chand, R., Singh, N.P. and Singh, V.K. 2004. Effect of weed con-
trol treatments on weeds and grain yield of late planted
urdbean during kharif season. Indian Journal of Pulses Re-
search 16: 163–64.
Choudhary, V.K., Kumar, S.P. and Bhagawati, R. 2012. Integrated
weed management in blackgram (Vigna mungo) under mid
hills of Arunachal Pradesh. Indian Journal of Agronomy 57:
382–85.
Goud, V.V., Murade, N.B., Khakre, M.S. and Patel, A.N. 2013. Ef-
ficacy of imazethapyr and quizalofop-ethyl herbicides on
growth and yield of chickpea. The Bioscan 8: 1015–18.
Nandan, B., Sharma, B.C., Kumar, A. and Sharma, V. 2011. Efficacy
of pre and post emergence herbicides on weed flora of
urdbean under rainfed subtropical Shiwalik foothills of
Jammu & Kashmir. Indian Journal of Weed Science 43:
172–74.
Nirala, H., Choubey, N.K. and Bhoi, S. 2012. Performance of post-
emergence herbicides and hand weedings with respect to
their effects on weed dynamics and yields of blackgram
(Vigna mungo L.). International Journal of Agricultural and
Statistics Sciences 8: 679–89.
Ram, H. and Singh, G. 2011. Studies on the bio-efficacy of herbi-
cides for weed control in soybean (Glycine max L. Merrill)
under different sowing methods. Indian Journal of Ecology
38: 11–13.
Ram, H., Singh, G., Aggarwal, N., Buttar, G.S. and Singh, O. 2013.
Standardization of rate and time of application of
imazethapyr weedicide in soybean. Indian Journal of Plant
Protection 41: 33–37.
Rathi, J.P.S., Tewari, A.N. and Kumar, M. 2004. Integrated weed
management in blackgram (Vigna mungo L.). Indian Journal
of Weed Science 36: 218–20.
Royuela, M., Gonzalez, A., Gonzalez, E.M., Igor, C.A., Aparicio-
Tejo, P.M. and Gonzalez-Murva, C. 2000. Physiological
consequences of continuous, sub-lethal imazethapyr supply
to pea plants. Journal of Plant Physiology 157: 345–54.
Singh, G. 2011. Weed management in summer and kharif season
blackgram [Vigna mungo (L.) Hepper]. Indian Journal of
Weed Science 43: 77–80.
Sumachandrika, D., Venkateswarlu, B., Subbaaiah, G. and
Swarajyalaxmi, G. 2003. Relative efficiency of soil solariza-
tion and herbicide for weed control in kharif blackgram.
Indian Journal of Weed Science 35: 139–40.
Tan, S., Evans, R.R., Dahmer, M.L., Singh, B.K. and Shaner, D.L.
2005. Imidazolinone-tolerant crops: history, current status
and future. Pest Management Science 61: 246–57.
Tewari, A.N., Rathi, J.P.S., Tiwari, S.N. and Tripathi, A.K. 2004.
Efficacy of imazethapyr - a selective herbicide in green gram
with special reference to Parthenium hysterophorus control.
Farm Science Journal 13: 114–15.
Vivek, Rana, N.S., Singh, R. and Tomar, S.S. 2008. Effect of weed
interference on weeds and productivity of blackgram
(Phaseolus mungo). Indian Journal of Weed Science 40: 65–
67.
Wilson, D.O. and Reisenauer, H.M. 1963. Determination of
leghaemoglobin in legume nodules. Analytical Biochemistry
6: 27–30.