Chief EditorT. Mohapatra
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Full Research Article
Effect of Herbicidal Weed Management on Productivity and Profitability of Summer Cowpea
Methods: The experiment was laid out at Agronomy Main Research Farm, Odisha University of Agriculture and Technology, Bhubaneswar, Odisha (India) during the summer season of 2021 and2022 in a randomized block design (RBD) comprised of eight treatment with three replications. Standard procedures were followed for the observations and statistical analysis of the data.
Result: The experimental results revealed that ready mix of pendimethalin+imazethapyr-750 g/ha significantly control the mixed flora of weeds which resulted significant increase in growth and yield. Ready mix application of pendimethalin + imazethapyr 750 g/ha registered the highest benefit to cost ratio.
The low productivity of cowpea can be attributed to several limiting factors. However among all limiting factors, weed management are most important. Weeds impose competition for nutrients, solar radiation, water and it sets in at the early crop growth stages and their relative density plays significant role in reducing yield of crops. As regards the various weed control measures, manual eradication has proved its superiority over all the measures in managing weeds; however the adoption of this technique has not gained popularity as it is time consuming. Weed interference in cowpea not only reduced the final stand but also the grain yield up to 90% (Freitas et al., 2009). Timely weeding is most important to minimize the yield of losses and therefore under such circumstances the only effective tool left is to control weeds through the use of chemicals. Management of weeds through the use of chemicals has also been found as effective as realized under manual eradication in various crops including over and above benefits in saving extra costs involved in use of labour on manual eradication of weeds. For controlling weeds in cowpea it is also important to determine the efficacy of pre and post-emergence herbicides. The application of pendimethalin as a pre-emergence spray suppressed early emerging weeds (Gurjar et al., 2001 and Chauhan et al., 2002). Imazethapyr herbicide was used in leguminous crops to combat important annual and perennial grasses as well as broadleaved weeds (Dixit and Varshney, 2007 and Savu et al., 2006). Sequential application of herbicides in a short duration crop like cowpea, not only increases the cost of cultivation but also create cumbersome in its application. Therefore ready mix herbicides of different groups are now becoming popular among farming community. Hence, keeping the above facts in view, the present investigation was undertaken to assess the performance of ready mix application of herbicides for providing effective weed control in cowpea.
MATERIALS AND METHODS
The data obtained on various parameters - weed count, weed density, yield attributes and yield, were tabulated and subjected to analysis of variance techniques as described by Gomez and Gomez (1984).
RESULTS AND DISCUSSION
The experimental field was infested mainly with Cynodon dactylon L., Eleusine indica L. and Eragrostis minor among grasses, Cyperus rotundus L. among sedge and Vigna trilobata L., Euphorbia hirta L., Cassia tora L., Celosia argentea L.and Ageratum conyzoides L. among broad leaved weeds.
Effect on weed density and dry weight
Critical observation on pooled data taken at 20 DAS indicates that ready mix application of Pendimethalin + Imazethapyr 750 g ha-1, Pendimethalin 678 g ha-1 and hand weeding significantly reduced weed count and dry weight of weeds as compared to other treatments (Table 1). Hence pre-emergence herbicides showed their efficiency at earlier stage of crop growth but later as the crop progresses the effect also declines and thus resulting in increase in weed density and dry weight. At 40 DAS significantly lowest weed density and weed dry weight was recorded with ready mix application of Propaquizafop + Imazethapyr (7.0 m-2) and (1.67 g m-2) which was followed by Fluazifop-p-butyl + Fomesafen at 40 DAS (7.5 m-2) and (2.07 g m-2) along with weed free treatment(6.43 m-2) and (1.63 g m-2). Maximum number of weed density and dry weight was recorded from weedy check at both stages of crop growth. The results are in agreement with the findings of Kumar and Singh (2017) and Yadav et al., (2018).
Effect on nodules
Observations taken on nodule number of cowpea vary at 40 and 60 DAS of crop growth. Maximum number of nodules was noticed in (hand weeding
Effect on Rhizobium population
The effect of herbicides on Rhizobium population is tabulated in Table 2. At 40 DAS, Highest Rhizobium population of 6.54 × 104 CFU/g soil was noticed in weed free treatment. However, among herbicides, highest Rhizobium population observed with pendimethalin + imazethapyr treated plots (4.12 × 104 CFU/g soil) The lowest population of Rhizobum was observed in the oxyflourfen treated plots (3.11 × 104 CFU/g soil). Almost a similar trend was followed at 60 DAS. Similar findings were observed by Sah (2022) and Ahmad and Khan (2010).
Effect on yield
The seed yield, haulm yield (kg ha-1) along with harvest index (%) are presented in (Table 3).The highest seed yield was recorded in weed free treatment (997.68 kg ha-1) which was statistically at par with ready mix application of pendimethalin + imazethapyr 750 g ha-1 treatment (961.13 kg ha-1) and ready mix application of fluazifop-p-butyl + fomesafen 125 g ha-1 (897.97 kg ha-1).These three treatments were found significantly superior to rest of the treatments. Next best treatments in registering higher seed yield was obtained with propaquizafop + imazethapyr 75 g ha-1 (824.55 kg ha-1) followed by pendimethalin (775.62 kg ha-1). The lowest seed yield was found in the untreated plot (541.65 kg ha-1). The highest haulm yield (2114.42 kg ha-1) was recorded in weed free treatment (2118 kg ha-1), which remained at par with Pendimethalin + imazethapyr 750 g ha-1 (2114.42 kg ha-1 and Fluazifop-p-butyl + fomesafen 125 g ha-1 (2015.42 kg ha-1). These three treatments were found significantly superior to rest of the treatments. In all the weed control treatments the harvest index was significantly higher than weedy check, highest being the Pendimethalin + imazethapyr 750 g ha-1 (31.25%). These results are in close conformity with Chinnusamy et al., (2010), Hanumanthappa et al., (2012).
The highest benefit to cost ratio was found in ready mix application of pendimethalin+ imazethapyr 750 g/ha is (2.61) followed by fluazifop-p-butyl + fomesafen 125 g/ha (2.34) (Table 3). Weedy check recorded the minimum value of 1.69. Weed free plot despite provide highest yield and gross return, the B:C Ratio is low. This is due to high cost of manpower involved. These findings are in conformity with Patil et al., (2014).
CONFLICT OF INTEREST
- Anonymous, (2018). Annual Report, AICRP on Weed Management, Bhubaneswar, Odisha. pp.16-18.
- Ahemad, M. and Khan, M.S. (2010). Growth promotion and protection of lentil (Lens esculenta) against herbicide stress by Rhizobium species. Annals of Microbiology. 60: 735-745.
- Bunt, J.S. and Rovira, A.D. (1955). Microbiological studies of some subantarctic soils. Journal of Soil Science. 6: 119-128.
- Chauhan, Y.S., Bhargava, M.K., Jain, V.K. (2002). Effect of herbicides on weeds and soyabean (Glycine max). Indian Journal of Weed Science. 34: 213-216.
- Chinnusamy, C., Senthil, A., Prabu Kumar, G., Prabhakaran, N.K. (2010). Identification of threshold level of horse purslane in irrigated cowpea. Indian Journal of Weed Science. 42: 91-94.
- Choudhary, S.K., Choudhary, G.L., Prajapat, K. (2013). Response of cowpea (Vigna unguiculata L.) to fertility levels and mulching. Environment and Ecology. 31: 492-495.
- Dixit, A and Varshney, J.G. (2007). Bioefficacy of imazethapyr against weeds in soybean. Annual Report of. National Research Centre for Weed Science, Jabalpur. pp.7-8.
- FAO, (2016). FAO report. http://www.fao.org/faostat/en/#data.
- Freitas, F.C.L., Medeiros, V.F.L.P., Grangeiro, L.C., Silva, M.G.O., Nascimento, P.G.M.L., Nunes, G.H. (2009). Weed interference in cowpea. Indian Journal of Weed Science. 27: 241-247.
- Gomez, K.A. and Gomez, A.A. (1984). Statistical Procedure for Agricultural Research (2nd Edition). John Wiley and Sons. New York. pp-680.
- Gurjar, M.S., Kushwah, S.S., Jain, V.K., Kushwah, H.S. (2001) Effect of different herbicides and cultural practices on growth, yield and economics of soybean [Glycine max (L.) Merrill.]. Agricultural Science Digest. 21: 13-16.
- Hanumanthappa, D.C., Mudalagiriyappa, Rudraswamy, Kumar G.N.V., Padmanabha, K. (2012). Effect of weed management practices on growth and yield of cowpea (Vigna unguiculata L.) under rainfed conditions. Crop Research (Hisar). 44: 55-58.
- Jackson, M.L. (1967). Soil Chemical Analysis. Prentice Hall of India, Pvt. Ltd., New Delhi. 1: 111-203.
- Kumar, S. and Singh, R. (2017). Integrated weed management in cowpea (Vigna unguiculata L.) under rainfed conditions. International Journal of Current Microbiology and Applied Sciences. 6: 97-101.
- Patil, B.C., Padanad, L.A., Yashvantkumar, K.H., Soumya, S., Ravi, L. (2014). Efficacy and economics of integrated weed management in vegetable cowpea (Vigna unguiculata L.). Hind Agricultural Research and Training Institute. 1: 124- 127.
- Sah, A. (2022). Impact of herbicides on soil microorganisms, nodulation and yield of chickpea. Legume Research. 45: 1325-1329. Doi: 10.18805/LR-4247.
- Savu, R.M., Choubey, N.K, Tiwari, N. (2006). Chemical weed control in groundnut (Arachis hypogaea L.) under vertisols of Chhatisgarh plains. Journal of Interacademicia. 10: 156- 159.
- Singh, B.B., Hakeem, A, Shirley, A., Tarawali, A., Fernandez-Rivera, S., Abubakar, M. (2012). Improving the production and utilization of cowpea as food and fodder. Field Crop Research. 84: 169-177.
- Yadav, T., Chopra, N.K., Kumar, R., Soni, P.G. (2018). Assessment off critical period of crop weed competition in forage cowpea (Vigna unguiculata L.) and its effect on seed yield and quality. Indian Journal of Agronomy. 63: 124-127.
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