Open Access
Dujeshwer Kurrey1 , Rajendra Lakpale1 and Rahul Singh Rajput2
1Department of Agronomy, Indira Gandhi Krishi Vishwavidyalaya., Raipur – 492 012, India.
2Department of Plant Pathology, Indira Gandhi Krishi Vishwavidyalaya., Raipur – 492 012, India.
J Pure Appl Microbiol. 2016;10(4):2931-2935
https://doi.org/10.22207/JPAM.10.4.59 | © The Author(s). 2016
Received: 13/06/2016 | Accepted: 19/09/2016 | Published: 31/12/2016
Abstract

A field experiment was conducted at Research Farm of IGKV, Raipur during Kharif 2013 to evaluate the combined effect of herbicide and insecticide on growth, nodulation and Rhizobium population in soybean. All the herbicidal treatments recorded significantly at par to improving growth characters viz. LAI, CGR and RGR. Highest Nodule number (74.2 plant-1) and nodule dry weight (74.2 mg plant-1) was resulted by Quizalophop ethyl 5 EC @ 1.0 l ha-1 as sole or combination with insecticides. Whereas all the pesticidal treatments found negative impact on microbial count which was recorded superior (62.1 x106 g-1 soil) under Untreated Check. The highest seed yield (2323 kg ha-1), stover yield (2943 kg ha-1), net income (63655 ¹ /ha) and B:C ratio (3.09) was recorded under Imazathapyr 10 [email protected] l ha-1.

Keywords

Herbicide, Insecticide, Soybean, nodulation and Rhizobium.

Introduction

Soybean is one of the most important leguminous oil seed crops of great economic value, occupying an important position in the world trade as it is important in the soil by fixing atmospheric nitrogen through Rhizobium bacteria that lives in their root nodules (Stewart 2009). In Chhattisgarh, soybean occupies 0.147 million ha with production of 0.134 million tone and average productivity of 915 kg ha-1 (www.sopa.org/REK2014.pdf, 2014). It grows well during the kharif or monsoon, season (July-October) in the dry-land areas of peninsular India. In kharif season due to continuous rains there will be high weed infestation and high weed competition is one of the most of important causes of yield loss in soybean and is estimated to be 22-77% [Kuruchania et al., 2001]. The costly and unavailability of labours coupled with unfavourable weather conditions offer an opportunity for the chemical weed control. (Amaregonda et al., 2013). Soybean is very much susceptible to insect attack from seedling to mature stage. All parts of the plant including plant leaves, stems and pods are subjected to attack by different species of insect in India. Both the constraints drastically reduces the growth of the soybean results in lower crop yield. The Rhizobium inoculants are commonly applied to seeds of legume crops to ensure effective nitrogen fixation by Rhizobium, thereby making the one essential nutrients available to the crop. The use of pesticides has become an integral and economically essential part of agriculture. There are reports which suggest that herbicides when applied indiscriminately have variable effects on legume Rhizobium symbiosis (Khan et al., 2004). Herbicides may have negative effects on growth of rhizobia. Considering the above facts we tried to control the weed and pests in a single spray and to evaluate the effect on growth behavior, nodulation and Rhizobium count in soybean.

Materials and Methods

A field experiment was conducted to evaluate the effect of herbicide and insecticide combination on growth, nodulation and Rhizobium population in soybean at Instructional cum Research Farm, Indira Gandhi Krishi Vishwavidyalaya, Raipur (C.G.) during kharif 2013. The experiment was laid out in Randomized Block Design (RBD) with four replication and twelve treatments which included rynaxypyre 20 EC @100 ml ha-1 , indoxacarb 14.5 EC @ 300 ml ha-1 , quinolphos 25 EC @1.5 l ha-1 , imazathapyr 10 SL @1.0 l ha-1, quizalophop ethyl 5 EC @ 1.0 l ha-1 as alone and with combination of herbicide and insecticide and Untreated Check. All the treatments were applied at 20 DAS (Day after sowing) as a tank mix at time of spraying. Soybean variety JS-335 was sown with spacing of 30 X 7 cm and seed rate of 65 kg ha-1 was used. Seed was treated by Rhizobium culture @10 g kg-1 seed at the time of sowing. The study on Leaf area index observed at 30, 60 and 90 DAS. The leaf area existing on unit area was proposed by Watson (1952) as an appropriate measure of crop growth. This measures is known as leaf area index. It is dimensionless ratio and calculated by following formula-

Leaf area index (LAI) = Total leaf area of plant-1 (cm2)/Total ground area of plant-1 (cm2)

Crop growth rate was calculated from the dry weight taken at different time intervals. It denotes overall growth rate of the crop plant and it is measured after fix period of the time, irrespective of the previous growth rate. The value was calculated by using the following formula suggested by Leopold and Kridermann (1975)-

Crop growth rate (CGR) (g plant-1 day-1) = W2 – W1 ( Difference in oven dry biomass at the time interval)/ t2 – t(Time interval in days )

The relative growth rate indicates the increase in dry weight per unit of original dry weight over any specific time interval. The values were computed by using the following formula suggested by Leopold and Kridemann (1975)-

Relative growth rate (RGR)  (g g plant-1 day-1) = lnW2 – lnW1/ t2 – t1

Where, ln   = Logarithm at base (natural log)

The number of nodules were recorded from three randomly selected plants in each plot. The uprooting of sample were preformed with the help of core cutting equipment along with the soil upto effective root zone. The roots of the plant were washed in sieve with running water and effective root nodules were separated and counted. The counted nodules were dried at 60oC for 48 hours in hot air oven thereafter dry weight of nodules was recorded by an electronic digital balance and average dry weight of nodule plant-1 was worked out. Analysis of rhizobium population was done by serial dilution plating method (Subba Rao 1988). The sampling of soil was done from 5-10 cm depth at, 50 DAS. Yield and yield attributes were recorded at harvest. The economics of soybean crop production pertaining to each of the treatment has been worked out in terms of cost of cultivation. Gross return (Rs. ha-1) was obtained by converting the harvest into monetary terms at the prevailing market rate during the course of studies for every treatment. Net return (Rs. ha-1) was obtained by deducting cost of cultivation from gross return.

RESULTS AND DISCUSSION

Effect on growth behavior
Leaf area index
Leaf area index (LAI) is the important physiological parameter for growth and yield. LAI of soybean showed increasing trend upto 60 DAS at higher pace and there after increased at slower pace (Fig. 1). Maximum LAI was recorded under the treatment Rynaxypyre 20 EC @100 ml ha-1 + Quizalophop ethyl 5 EC @ 1.0 l ha-1, followed by Imazathapyr 10 SL @1.0 l ha-1 and Rynaxypyre 20 EC @100 ml ha-1 + Imazathapyr 10 SL @1.0 l ha-1. Minimum LAI was recorded under the treatment of Indoxacarb 14.5 EC @ 300 ml ha-1. Increased leaf area might have enhanced the photosynthesis due to which plant dry matter accumulation was higher under these treatments. There was lower weed competition in terms of dry matter of weeds, higher number of branches, leaves and suitable environment might led to higher value of leaf area, which allowed soybean to absorb required amount of nutrient, water and sunlight for expanding the leaf to the plant potential. Similar trends were also recorded by (Amaregonda et al., 2013).


Fig 1: Leaf area index as affected by combined use of herbicide and insecticide Crop growth rate

Crop growth rate
Crop growth rate showed increasing trend upto 60 DAS and declined thereafter till harvest depicted in Fig. 2. During 0-30 DAS, comparatively similar crop growth rate value were recorded under all the treatments. After 30 DAS, maximum crop growth rate was recorded under Imazathapyr 10 SL @1.0 l ha-1 followed by Quizalophop ethyl 5 EC @ 1.0 l ha-1. Minimum crop growth rate was observed under non herbicidal treatments during entire growth period in soybean. Declined crop growth rate was caused by senescence of leaves probably owing to competition from weeds for solar radiation and also due to density of weeds higher in these periods.  (Jakhar and Sharma, 2015) also reported that weed free plots recorded higher value of CGR.

Fig. 2: Crop growth rate (g plant -1 day-1) of soybean as affected by combined use of herbicide and insecticide

Relative growth rate
Relative growth rate (RGR) increased at higher pace from sowing to 90 DAS thereafter increased at slower pace (Fig. 3). The rate of RGR was recorded differently under different period of time. During 0-30 DAS, numerically maximum RGR was observed under treatment Indoxacarb 14.5 EC @ 300 ml ha-1 + Imazathapyr 10 SL @1.0 l ha-1 but During 30-60 DAS, maximum RGR was observed under treatment Quizalophop ethyl 5 EC @ 1.0 l ha-1. Rynaxypyre 20 EC @100 ml ha-1 recorded highest RGR during 60-90 DAS and Untreated Check recorded highest from 90 DAS to at harvest. Relative growth rate of soybean in above treatments was higher because of comparatively less crop-weed and pest competition. The increased sink size, stored the photosynthates very effectively and ultimately transformed in the shape of more dry matter accumulation which resulted in higher relative growth rate.

Fig. 3: Relative growth rate (g g-1 plant -1 day-1) of soybean as affected combined use of herbicide and insecticide

Effect on nodulation
The applied herbicides did not show adverse effects on the number and dry weight of root nodules reported earlier by (Jha et al, 2014) and depicted in (Table 1). At 40 DAS, significantly maximum number of root nodules and dry weight of nodule was observed under treatment of Rynaxypyre 20 EC @100 ml ha-1 + Quizalophop ethyl 5 EC @ 1.0 l ha-1, however at 60 DAS, Quizalophop ethyl 5 EC @ 1.0 l ha-1 recorded highest root nodule which was at par with all herbicidal treatments but Quinolphos 25 EC @1.5 l ha-1 + Quizalophop ethyl 5 EC @ 1.0 l ha-1 recorded highest dry weight of nodule. Increased number of root nodules and dry weight may be due to the favorable microclimate after suppression of weeds near the root zone and greater infection of Rhizobium in the growing roots of soybean crop. Higher nodulation fixed the atmospheric nitrogen which ultimately supported in higher crop growth of soybean. (Jha et al, 2014) and (Kandaki et al, 2015) reported that weed free treatments enhances nodule number and nodule dry weight.
Table (1):
Effect of herbicide and insecticide on nodulation and Rhizobium population in soybean.

Treatments Number of nodule plant-1 Dry weight of nodule (mg plant-1) Rhizobium population (x 106 g-1 soil)
40 DAS 60 DAS 40 DAS 60 DAS 50 DAS
T1-Rynaxypyre 20 EC @ 100 ml/ha 30.3 55.4 150 520 43.9
T2– Indoxacarb 14.5 EC @ 300 ml/ha 29.4 54.3 190 510 45.4
T3– Quinolphos 25 EC @ 1.5 l/ha 27.9 61.3 180 510 51.1
T4– Imazathapyr 10 SL @ 1.0 l/ha 35.4 69.3 160 640 52.8
T5– Quizalophop ethyl 5 EC @1.5 l/ha 29.0 74.2 160 560 33.5
T6– Rynaxypyre 20 EC @ 100 ml/ha + Imazathapyr 10 SL @ 1.0 l/ha 28.9 56.1 150 480 39.3
T7– Rynaxypyre 20 EC @ 100 ml/l +

Quizalophop ethyl 5 EC @ 1.0 l/ha

40.0 71.2 200 560 45.8
T8– Indoxacarb 14.5 EC @ 300 ml/ha +Imazathapyr 10 SL @ 1.0 l/ha 28.1 70.1 140 580 50.9
T9– Indoxacarb 14.5 EC @ 300 ml/ha+

Quizalophop ethyl 5 EC @ 1.0 l/ha

25.4 72.4 160 560 58.2
T10– Quinolphos 25 EC @ 1.5 l/ha +

Imazathapyr 10 SL 1.0 l/ha

32.4 66.0 160 570 50.8
T11– Quinolphos 25 EC @ 1.5 l/ha +

Quizalophop ethyl 5 EC @ 1.0 l/ha

30.1 65.7 170 760 48.1
T12-Untreated check 29.0 62.1 170 580 62.1
SEm (±) 1.4 3.5 10.0 50.0 2.1
CD (P=0.05) 4.1 10.0 NS 140.0 6.1

Effect on Rhizobium population (x 106 g-1 soil)
It is reported that application of pesticides both in crop and soil is known to affect microbial activity. (Shankar et al. 2012). Significantly maximum rhizobial population was observed under treatment Untreated Check (Table 1), which was at par with treatment Indoxacarb 14.5 EC @ 300 ml ha-1 + Quizalophop ethyl 5 EC @ 1.0 l ha-1. The highest Rhizobial population observed under Untreated Check might be due to the provision of food in the form of organic matter by crop as well as weeds and by secretion of organic acids, beneficial for rhizobium bacteria. Similar findings were also reported by Gupta et al. (2013).

Effects on yield and economics
All herbicidal treatment significantly increased the yield and yield component like seed yield, straw yield, harvest index, net income and B:C ratio in soybean (Table 2). The significantly highest seed yield, straw yield, net income and B:C ratio was recorded under Imazathapyr 10 SL @1.0 l ha-1 which was comparable with all herbicidal treatments. However Indoxacarb 14.5 EC @ 300 ml ha-1 + Quizalophop ethyl 5 EC recorded highest harvest index. The higher seed yield under this treatment were might be due to better efficacy of herbicide at initial stage of crop growth providing weed free environment to the crop. Similar results was also reported by Venkatesha et al. (2008), Goud et al. (2013) and Sangeetha et al. (2013).
Table (2):
Effect of herbicide and insecticide on yield and economics in soybean.

Treatment
Seed yield (kg/ha)
Stover yield (kg ha-1)
Harvest index (%)
Net income (₹/ha)
B:C ratio
T1– Rynaxypyre 20 EC @ 100 ml/ha
1550
2171
41.67
36828
1.88
T2– Indoxacarb 14.5 EC @ 300 ml/ha
1513
2031
42.70
35785
1.86
T3– Quinolphos 25 EC @ 1.5 l/ha
1548
2213
41.20
37540
1.99
T4– Imazathapyr 10 SL @ 1.0 l/ha
2323
2943
43.84
63655
3.09
T5– Quizalophop ethyl 5 EC @1.5 l/ha
2201
2684
45.09
60026
3.05
T6– Rynaxypyre 20 EC @ 100 ml/ha + Imazathapyr 10 SL @ 1.0 l/ha
2205
2756
44.28
57938
2.63
T7– Rynaxypyre 20 EC @ 100 ml/l + Quizalophop ethyl 5 EC @ 1.0 l/ha
2247
2835
44.24
60387
2.86
T8– Indoxacarb 14.5 EC @ 300 ml/ha + Imazathapyr 10 SL @ 1.0 l/ha
2049
2612
43.77
52726
2.44
T9– Indoxacarb 14.5 EC @ 300 ml/ha+ Quizalophop ethyl 5 EC @ 1.0 l/ha
2030
2484
47.11
52833
2.55
T10– Quinolphos 25 EC @ 1.5 l/ha + Imazathapyr 10 SL 1.0 l/ha
2254
2887
43.94
60524
2.85
T11– Quinolphos 25 EC @ 1.5 l/ha + Quizalophop ethyl 5 EC @ 1.0 l/ha
2255
2845
44.29
61417
3.02
T12– Untreated check
1521
1978
43.50
37270
2.08
SEm (±)
138
145
1.39
CD (P=0.05)
381
416
NS
References
  1. Amaregonda, A., Jadhav, J., Chetti, M. B. and Nawalagatti. Effect of weedicides on physiological parameters, growth, yield and yield component of soybean (Glycine max. L) and weed growth. J. of Agri. and Allied Sci. 2013; 4(2): 12-15.
  2. Goud, V.V. Murade, N.B., Khakre, M.S. and Patil, A.N. Efficacy of imazethapyr and quizalofop-ethyl herbicides on growth and yield of chickpea. The bioscan 2013; 8(3): 1015-1018.
  3. Gupta, A., Lakpale, R., Tandon, A. and Pandagare, T., Effect of weed management on weed control, nodulation and soil rhizobium in soybean. J. of Agri. Iss. 2013; 18(1&2): 108-110.
  4. Jakhar, R.R. and Sharma, R. Growth and yield attributes as influenced by integrated weed management in soybean [ Gycine max (L.) Merrill].  Ann. of Bio. 2015; 31(2):190-194.
  5. Jha, B. K., Chandra, R. and Singh, R., Influence of post emergence herbicides on weeds, nodulation and yield of soybean and soil properties. Leg. Res. 2014; 37:45-54.
  6. Kandaki,, M. S., Potdar, M. P. and  Nirmalanath, J., Influence of post emergence herbicide Cycloxydim 20% EC on soil enzymatic activity, nodulation, growth and yield in soybean. Bioch. and Cell. Arch. 2015; 15(2):557-560.
  7. Khan, M.S., Zaidi, A., Aamil, M., Influence of herbicides on chickpea—Mesorhizobium symbiosis. Agronomie 2004; 24:123-127.
  8. Kuruchania, S.P., Rathi, G.S., Bhalla, S. and Mathew, R., Bio efficacy of post emergence herbicides for weed control in soybean. Indian J. Weed Sci. 2001; 33(1&2): 34 -37.
  9. Leopold, C.A. and Kridemann, E.P, Plant growth and development. Tata Mc-Graw Hill Publishing Co. Ltd., New Delhi, 1975.
  10. Sangeetha, C., Chinnusamy, C. and Prabhakaran, N. K., Early post-emergence herbicide for weed control in soybean. Indian J. Weed Sci. 2013; 45: 142-142.
  11. Stewart, S.D., F.R. Musser and A.L. Catchot, Soybean losses for Mussissippi and Tennessee. Midsouth. J.r., 2009; 2: 42-46.
  12. Subba Rao, N.S., Biological nitrogen fixation. Oxfored and I.B.H. Pub. Co., New Delhi, 1988.
  13. Venkatesha, M.M., Babalad, R.B., Patil, V.C., Patil, B.N. and Hebsur, N.S., Bio-efficacy and phytotoxicity evaluation of imazethapyr in soybean. Indian J. Weed Sci. 2008; 40: 214-216.
  14. Watson, D.J., Physiological aspects of crop yield. Adv. in Agron. 1952; 4: 1001-1045.
  15. www.sopa.org/REK2014.pdf. 2014. The soybean processors association of India. Indore, India.

Article Metrics

Article View: 2352

Share This Article

© The Author(s) 2016. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.