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    • Rajan Katoch, Anita Singh, Neelam Thakur/ International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.828-834 Effect Of Weed Residues On The Physiology Of Common Cereal Crops Rajan Katoch, Anita Singh and Neelam Thakura Department of Crop Improvement, College of Agriculture, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur (H.P.) – 176 062 (India) a Department of Biosciences, Punjab Agricultural University, Ludhiana, India, 141004 * Corresponding author: Dr. Rajan Katoch Department of Crop Improvement, College of Agriculture CSKHPKVV, Palampur (H.P.) – 176062, IndiaAbstract The allelopathic influence of plant 1996). The effects of decaying weed residues dependresidues of three dominant weeds of North- upon the release of allelochemicals from them intoWestern Himalayan region, namely, Eupatorium the soil. These chemicals may be washed directlyadenophorum, Ageratum conyzoides and Lantana from the residues, or may result from microbialcamara was observed on the germination and activity during decomposition (Putnum and Dukeearly growth of three common cereal crops viz., 1978, Lynch and Cannell 1980, Kumar et al. 2006).Triticum aestivum cv. HPW-42, Oryza sativa cv. The effect of allelopathic chemicals tends to beHasanshrai Basmati and Zea mays cv. Girija. The highly species-specific (Stowe 1979, Melkania 1983).effect of soil amended with weed residues at two Normally, the effect is harmful, but beneficial effectconcentrations (5 g/100 g soil and 10 g/100 g soil) is also possible (Newman 1978).was compared with control. Among the test crops, Ageratum conyzoides, Lantana camara andmaize with larger seeds was least sensitive to the Eupatorium adenophorum are three exotic rapidlyexposure to various treatments while wheat and spreading weed species which have successfullypaddy with small seeds were comparatively invaded a large portion of North-Western Himalayansusceptible. The incorporation of weed residue in region in India. They are a major problem for thesoil had inhibitory effect on the per cent environmentalists, ecologists and agriculturists. Thegermination and shoot length of seedlings of test present investigation was carried out to assess thecrops. The results of the study indicated the allelopathic potential of the plant residues of theseallelopathic influence of weed residue on the common weeds of North-Western Himalayan regionphysiology of the crop plants. Therefore, the on the important cereal crops viz., Triticum aestivumintensive studies on allelochemicals released from cv. HPW-42, Oryza sativa cv. Hasanshrai Basmatidecaying weed residues in the natural and Zea mays cv. Girija.environment where additive or synergistic effectsbecome significant even at low concentrations are Materials and Methodsdesirable to provide detail information on theinfluence of the weeds on crops of economic Collection and mechanical processing of plantinterest. materialAbbreviations: Fresh plant material (whole plant) of E. adenophorum, A. conyzoides and L. camara wasKey words: weeds, weed residue, germination, collected from the vicinity of CSKHPKV, Palampur,shoot length, Triticum aestivum, Oryza sativa, Zea India. The collected plant samples were allowed tomays shade dry. The dried material was crushed into fine powder using grinder and sieved through mesh ofIntroduction 2mm pore size. Weed infestation is one of the major causesof yield reduction in crops. The incidence of Procurement of seedsallelopathic effect of weeds on growth of crops has Seeds of the cereal crops studied werebecome increasingly widespread. When the two plant procured from the Department of Crop Improvement,species grow together, they interact with each other CSKHPKV, Palampur. The seeds were surface-either inhibiting or stimulating their growth or yield sterilized with sodium hypochlorite and used forthrough direct or indirect allelopathic interaction further bioassay studies.(Kumar et al. 2006). Several reports havedocumented the deleterious effect of decaying weed Pot experimentresidues on the growth and yield of subsequent crops To study the effect of decaying weed residuein the field (Guenzi and McCalla 1966, Shaukat et al. on germination and seedling growth of test crops,1985, 2003, Burhan and Shaukat 1999, Singh et al. dried powdered material of E. adenophorum, A.1988, Angiras et al. 1987, 1988, Das and Choudhury conyzoides and L. camara was mixed thoroughly 828 | P a g e
    • Rajan Katoch, Anita Singh, Neelam Thakur/ International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.828-834with SoilriteTM consisting of peat moss, perlite and L. camara amended soil (10 g/100 g soil). In case ofvermiculite (1:1:1 v/v/v) at the concentration of 5 maize, the per cent germination was not significantlyg/100 g soil and 10 g/100 g of soil. After mixing, the altered by various treatments except E. adenophorumsoil was equally transferred into plastic pots of 9.5 (10 g/100 g soil) which showed significant inhibitioncm diameter. Pots were watered once and soil was as compared to the control.left for biodegradation. The pots were kept in aglasshouse under controlled conditions. After one Effect of weed residues on shoot weightweek, 10 seeds of test crops were sown in each pot. The shoot weight (g) of seedlings of all testFor controls, SoilriteTM with no weed residue was crops under the influence of various treatments onused. The experiment was carried out in triplicate for fourteenth day after sowing is presented in Table 1.each treatment and control. Seedlings were irrigated The shoot weight of wheat seedlings grown in soilwith tap water throughout the experiment. Pot amended with E. adenophorum (5 g/100 g soil) andexperiment included the following treatments: L. camara (5 g/100 g soil and 10 g/100 g soil) wasT0 : SoilriteTM significantly higher as compared to the control.TE5: SoilriteTM + E. adenophorum (5 g/100 g Wheat seedlings of all other treatments showedsoil) significantly lesser shoot weight as compared to theTE10: SoilriteTM + E. adenophorum (10 g/100 g control. No significant change in shoot weight ofsoil) paddy seedlings was observed in all the treatments asTA5: SoilriteTM + A. conyzoides (5 g/100 g soil) compared to the control. However, A. conyzoides (5TA10: SoilriteTM + A. conyzoides (10 g/100 g soil) g/100 g soil) led to significantly higher shoot weightTL5: SoilriteTM + L. camara (5 g/100 g soil) of paddy seedlings as compared to other treatments.TL10: SoilriteTM + L. camara (10 g/100 g soil) The shoot weight of maize seedlings exposed to The experiment was extended over a period various treatments was significantly higher than theof fourteen days to allow maximum seedling growth. control.The seed was considered germinated when theplumule emerged. Germination counts were made Effect of weed residues on root weightdaily up to seven days. The length of shoot of The root weight (g) of seedlings of all testseedlings was recorded initially on seventh day and crops under the influence of various treatments onthen on fourteenth day after sowing. On fourteenth fourteenth day after sowing is presented in Table 1.day post-sowing, the weight of shoot and root of The root weight of wheat seedlings grown in soilvarious treatments of all the test crops was recorded. incorporated with E. adenophorum (5 g/100 g soil and 10 g/100 g soil), A. conyzoides (5 g/100 g soil)Statistical Analysis and L. camara (5 g/100 g soil) was significantly Three replications were maintained and higher as compared to the control. No significantcompletely randomized design was followed for difference was observed in the root weight of wheatstatistical analysis (Panse and Sukhatme 1989). The seedlings grown in soil incorporated with A.data were subjected to analysis of variance conyzoides (10 g/100 g soil) and L. camara (10 g/100(ANOVA) at p< 0.05. In case of values found non- g soil) as compared to the control. The root weight ofsignificant during ANOVA, the data was subjected to paddy seedlings grown in soil incorporated with E.Duncan’s Multiple Range Test (DMRT) at p < 0.05. adenophorum (10 g/100 g soil) was statistically similar to the control while all other treatmentsResults revealed significantly higher root weight onEffect of weed residues on seed germination fourteenth day post-sowing. The root weight of maize The germination per cent of seeds of all the seedlings grown in soil incorporated with E.test crops under the influence of various treatments is adenophorum (5 g/100 g soil and 10 g/100 g soil)presented in Table 1. The per cent germination of was statistically similar to the control while all otherwheat seeds in soil amended with E. adenophorum (5 treatments revealed significantly higher root weightg/100g soil) was significantly higher as compared to on fourteenth day post-sowing.the control while all other treatments showedsignificantly lower per cent germination. No Effect of weed residues on shoot lengthsignificant reduction in the per cent germination of On seventh day, a significant reduction inseeds of paddy was observed in the soil amended the shoot length of wheat, paddy and maize waswith 5 g/100 g soil of either E. adenophorum or A. observed for all the treatments except paddy grown inconyzoides or L. camara as compared to the control. soil amended with A. conyzoides (5 g/100 g soil). OnHowever, significant reduction in per cent fourteenth day, the shoot length of wheat seedlingsgermination of paddy seeds was observed when the was significantly less in the soil amended with E.soil was amended with 10 g/100 g soil of either E. adenophorum (10 g/100 g soil) and A. conyzoides (5adenophorum or A. conyzoides or L. camara as g/100 g soil and 10 g/100 g soil) as compared to thecompared to the control or corresponding treatment at control. All other treatments showed statistically5 g/100 g soil. Maximum inhibition was revealed by similar shoot length of wheat seedlings. The paddy 829 | P a g e
    • Rajan Katoch, Anita Singh, Neelam Thakur/ International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.828-834seedlings grown in different amended soil showed germination and early growth of the successive cropsignificantly lesser shoot length as compared to the by interfering with the plant growth processes or bycontrol. In case of maize, significantly lesser shoot reducing cell division or auxin induced growth oflength was observed in soil amended with E. roots (Patrick and Koch 1958, McCalla and Haskinsadenophorum (10 g/100 g soil) and A. conyzoides (10 1964). The allelochemical can directly affect theg/100 g soil) as compared to the control. growth of receiver plants in soil as they are directly available for absorption by the plant (KobayashiDiscussion 2003). The allelochemicals absorbed by the seedling The present investigation clearly presented may slowly get metabolized. Earlier workers havethe allelopathic influence of decaying weed residue also reported inhibition of seed germination byof E. adenophorum, A. conyzoides and L. camara on allelochemicals through their interference in energythe germination and seedling growth of cereal crops metabolism, cell division, mineral uptake, blockageviz., wheat, paddy and maize. This could be assigned of hydrolysis of nutrients reserve and biosyntheticdue to release of allelochemicals or toxins into the processes (Rice 1984, Irshad and Cheema 2004) andsoil from the decaying residue by the action of micro- these factors may cause significant reductions in theorganisms during decomposition (McCalla and Duley growth of plumule and radical of various crops (Ogbe1948, Cochran et al. 1977, Putnum and Duke 1978, et al. 1994).Lynch and Cannell 1980, Harper and Lynch 1982, The stimulatory effect for shoot weight andLovett and Jessop 1982, Kumar et al. 2006). The root weight may emerge either from growthpotential effect is dependent on numerous factors that promoting compounds in the tissues themselves ortogether govern the rate of residue decomposition, enhanced microbial activity and concomitant nutrientthe net rate of active allelochemical production and availability (Rice 1986). As the allelopathic effectsthe subsequent degrees of phytotoxicity (An et al. are both stimulatory and inhibitory, both of these2002). The effects of secondary substances released effects can be utilized for higher crop productionby these mechanisms can be long lasting (Patrick (Oudhia et al. 1999a). Stimulatory allelopathic effects1971) or quite transitory (Kimber 1973) and can of any weed on crops can be utilized to developultimately influence practices like fertility, seeding ecofriendly, cheap and effective ‘green growthand crop rotations. An (2005) discussed about a promoters’ while inhibitory allelopathic effects ofmodel which provides an integrated view of the any weed or crop on weeds can be utilized to developallelopathic pattern of plant residues during ‘green herbicides’ (Oudhia et al. 1999b).decomposition, in terms of both the response of a Among the test cereal crops, maize withreceiver plant and allelochemical dynamics in the larger seeds was less sensitive to the decaying weedenvironment. They proposed two aspects of residue while wheat and paddy with small seeds wasallelopathy, stimulation and inhibition. The extent of more susceptible to the allelopathic effect ofeach over the whole course of residue decomposition decaying weed residue during germination. Thisis not balanced. They reported that the most severe observation is in agreement with the findings ofinhibition occurs at the early stages of residue Lucena and Doll (1976) who observed that seed sizedecomposition. Phytotoxicity was reported to is an important factor and species with small seedsproceeds from stimulation to inhibition and reach its are more adversely affected. Moreover, the inhibitionmaximum of inhibition soon after decomposition of seed germination and seedling growth wasstarts. concentration-dependent and numerically more In the present studies, soil incorporation of inhibition was observed at higher concentrations.the weeds under investigation was found to have These results correlated with the earlier reportsinhibitory effect on the per cent germination and indicating that allelopathy is a concentration-shoot length while a stimulatory effect was observed dependent phenomenon and includes bothfor shoot weight and root weight of seedlings. Earlier stimulatory and inhibitory activities (Wilson and Ricestudies have also revealed that situations abound 1968, Rai and Triputhi 1984, Rizvi and Rizvi 1987).where allelochemicals inhibit seed germination, but Most of the earlier studies had revealed thatseedling growth, and perhaps other growth the inhibition obtained in the laboratory experimentsparameters, remain unaffected. Wilson and Rice might differ from the situations in the fields as(1968) have reported both stimulatory and inhibitory allelopathic effects are often due to synergisticeffects on various crop species with decaying activity of allelochemicals rather than to singlematerials. compound. (Hauser 1993, Lisanework and Michelsen The allelopathic inhibitory effect of 1993, Tian and Kang 1994, Mehar et al. 1995,decaying weed residue of E. adenophorum, A. Hansen-Quartey et al.1998). Under field conditions,conyzoides and L. camara was found to be more additive or synergistic effects become significantpronounced during the seed germination and early even at low concentrations (Einhelliing anddays of seedling growth. The allelochemicals Rasmussen 1978). Thus, intensive studies onreleased from decaying weed residue into the soil allelochemicals from decaying weed residues are stillmay remain active and stable to affect the desirable to provide detail information on their 830 | P a g e
    • Rajan Katoch, Anita Singh, Neelam Thakur/ International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.828-834effects as farmers often leave weed residues uncared Referencesfor in their fields. 1. Ambika SR, Jayachandra (1980) Influence Different groups of workers have reported of light on seed germination in Eupatoriumthat E. adenophorum contains a large amount of odoratum L. Ind Forester 106: 637-640allelochemicals especially in the leaves, which inhibit 2. An M, Johnson IR, Lovett JV (2002)the growth of many plants in nurseries and Mathematical modelling of allelopathy: Theplantations (Ambika and Jayachandra 1980, Eze and effects of intrinsic and extrinsic factors onGill 1992, Gill et al. 1993, Zhao et al. 2009). residue phytotoxicity. Plant Soil 246: 11-22Similarly, allelochemicals from A. conyzoides have 3. An M. (2005) Mathematical Modelling ofbeen reported to inhibit seed germination and Dose-Response Relationship (Hormesis) inseedling growth of many plants (Wei et al. 1997, Allelopathy and its Application.Batish et al. 2006). Significant amount of water- Nonlinearity Biol Toxicol Med 3: 153–172soluble phenolics are reported to be present in 4. Angiras NN, Singh SD, Singh CM (1987)A. conyzoides infested soil, leaf debris, and debris- Allelopathic effects of important weedsamended soils (Batish et al. 2009). Our study is in species on germination and growth ofagreement with earlier studies where leaf debris of soybean and maize seedlings. Ind J WeedA. conyzoides have been reported to deleteriously Sci 19: 57-65affect the early growth of rice (Batish et al. 2009) and 5. Angiras NN, Singh SD, Singh CM (1988)wheat (Singh et al. 2003) by releasing water-soluble Allelopathic effects of some weeds onphenolic acids into the soil environment. Xuan and germination and growth of chickpea (Cicercoworkers (2004) have also reported allelopathic arietinum L.). Indian J Weed Sci 20: 85-87effect of A. conyzoides leaves on paddy weeds. 6. Batish DR, Singh HP, Kaur S, Kohli RKAllelopathic effects of Lantana camara on (2006) Phytotoxicity of Ageratumgermination and seedling vigour or many agricultural conyzoides residues towards growth andcrops have been reported (Oudhia et al. 1998, Oudhia nodulation of Cicer arietinum. Agric Ecosysand Tripathi 1999). Environ 113(1-4): 399-401 7. Batish DR, Kaur S, Singh HP, Kohli RSConclusion (2009) Nature of interference potential of The allelopathic activity of decaying weeds leaf debris of Ageratum conyzoides. Plantresidue is due to the various phytotoxic compounds Growth Regulation 57(2): 137-144released during their decomposition into the soil 8. Burhan N, Shaukat SS (1999) Allelopathicwhich may independently or jointly contribute to potential of Argemone mexicana L., aplant growth regulatory effect and inhibit tropical weed. Pak J Biol Sci 2: 1268-1273germination. The present study provides the evidence 9. Cochran VL, Elliott LF, Papendick RIof allelopathic potential of E. adenophorum, A. (1977) The production of phytotoxins fromconyzoides and L. camara on three cereal crops, surface crop residues. Soil Sci Soc Amer Jnamely, wheat, paddy and maize. However, more 41: 903-908detailed investigation is needed to study the specific 10. Das NR, Choudhury S (1996) Allelopathicrole in different crops. These results suggest major effects on rainfed jute under tillage andinhibitory effect of decaying weeds residue during nitrogen by weed Vandellia scabra benth.germination and early seedling growth of test crops The World Weeds 4 (1 and 2): 11-16while a stimulatory effect on shoot weight and root 11. Einhellig FA, Rusmussen JA (1978)weight of seedlings of test crops. Further Synergistic inhibitory effects of vanilic andinvestigation is needed to identify the active p-hydroxybenzoic acids on radish and graincompound(s) of the extracts responsible for their sorghum. J Chem Ecol 4: 425-436activity. The effect of these weeds on the germination 12. Eze JMO, Gill LS (1992) Chromolaenaand seedling growth of these crops in the natural odorata - a problematic weed. Compositaeenvironment where additive or synergistic effects Newsletter 20: 14-18become significant even at low concentrations should 13. Gill LS, Anoliefo GO, Iduoze UV (1993)also be investigated. Allelopathic effect of aqueous extract of Siam weed on growth of cowpea.Acknowledgements Chromoleana Newsletters 8: 1-11 The financial assistance provided by the 14. Guenzi WD, McCalla TM (1966) PhenolicDepartment of Biotechnology, New Delhi, acids in oats, wheat, sorghum, and cornGovernment of India, for funding the research project residues and their phytotoxicity. Agron J 58:is duly acknowledged. 303-304 15. Hansen-Quartey JA, Nyannapfene K, Materechera SA (1998) Effects of Aqueous Extracts from Artemisia afra parts and soil on seed germination and early seedling 831 | P a g e
    • Rajan Katoch, Anita Singh, Neelam Thakur/ International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.828-834 development in selected plant species. S Afr Biochemical aspects of plant and animal J Plant Soil 15(1): 1-5 coevolution, Ann. Proc. of the16. Harper SHT, Lynch JM (1982) The role of Phytochemical society of Europe 15, water-soluble components in phytotoxicity Academic Press, London, pp 327-343 from decomposing straw. Plant Soil 65: 11- 31. Ogbe FMO, Gill LS, Iserhien EOO (1994) 17 Effects of aqueous extracts of C. odorata L.17. Hauser S (1993) Effects of A. bateri, C. on radical and plumule growth and seedling simea, F. macrophylla and G. arborea height of maize, Z. mays L.. Compositae leaves on germination and early Newsletters 25: 31-38 development of maize and cassava. Agric 32. Oudhia P, Kolhe SS, Tripathi RS (1998) Ecosys Environ 45(3 and 4): 263-273 Negative (stimulatory) allelopathy of18. Irshad A, Cheema ZA (2004) Influence of Lantana camara L. on linseed var. Kiran In: some plant water extracts on the germination Abstract. International Symposium on and seedling growth of Barnyard grass (E. Microbial Biotechnology for Sustainable crus-galli (L) Beauv). Pak J Sci Ind Res Development and Productivity, Rani 43(3): 222-226 Durgavati University, Jabalpur (India) 14-1619. Kimber, RWL (1973) Phytotoxicity from November 1998. pp 64 plant residues. II. The effect of time of 33. Oudhia P, Pande N, Tripahti RS (1999a) rotting of straw from some grasses and Allelopathic effects of obnoxious weeds on legumes on the growth of wheat seedlings. germination and seedling vigour of hybrid Plant Soil 38: 347-361 rice. International Rice Research Notes20. Kobayashi (2003) Factors affecting 22(2): 36 phytotoxic activity of allelochemicals in 34. Oudhia P, Tripathi RS, Katiyar P (1999b) soil. Weed Biol Manag 4(1): 1-7 Weed management through green21. Kumar M, Lakiang JJ, Gopichand B (2006) allelochemicals: An eco-friendly approach Phytotoxic effects of agroforestry tree crops towards sustainable agriculture. In: Abstract. on germination and radicle growth of some National Seminar on Chemistry of food crops of Mizoram. Lyonia 11(2): 83-89 Environmental Pollution with special22. Lovett JV, Jessop RS (1982) Effects of Emphasis on Pesticides, Govt. D.B. Girl’s residues of crop plants on germination and P.G. College, Raipur (India) 28-29 January early growth of wheat. Aust J Agricul Res 1999. pp 22 33: 909-16 35. Oudhia P, Tripathi RS (1999) Allelopathic23. Lisanework N, Michelsen A (1993) effects of Lantana camara L. on rice. Agric Allelopathy in Agroforestry Systems: The Sci Digest 19(1): 43-45 effects of leaf extracts of C. lustanica and 36. Panse VG, Sukhatme PV (1989) Statistical three Eucalyptus spp. on four Ethiopian Methods for Agricultural Workers. Indian crops. Agrofor Syst 21(1): 63-74 Council for Agricultural Research, New24. Lucena HM, Doll J (1976) Growth- Delhi. pp 359 inhibiting affects of Cyperus rotundus L. on 37. Patrick, ZA (1971) Phytotoxic substances sorghum and soybeans. Revista Comalfi 3: associated with the decomposition in soil 241-256. Plant Growth Regular Abstr 3: plant residues. Soil Sci 111: 13-18 1192 38. Patrick ZA, Koch LW (1958) Inhibition of25. Lynch JM, Cannell RQ (1980) Plant respiration, germination and growth by residues. In: Crop seed and soil substances arising during the decomposition environment, Agric. Dev. Advisory Serv. of certain plant residues in soil. Can J Bot (U.K.) Ref. Book No. 321 pp 26-37 36: 621-64726. McCalla TM, Duley FL (1948) Stubble 39. Putnum AR, Duke WB (1978) Allelopathy mulch studies: Effect of sweetclover extract in agroecosystems Ann Rev Phytopathol 16: on corn germination. Science 108: 163 431-45127. McCalla TM, Haskins FA (1964) Phytotoxic 40. Rai JPN, Tripathi RS (1984) Allelopathic substances from soil micro-organism and effects of Eupatorium riparium on crop residues. Bacterial Rev 28: 181-207 population regulation of two species of28. Melkania NP (1983) Influence of certain Galinsoga and soil microbes. Plant Soil 80: selected tree species on ground flora, Ph.D. 105-117 Thesis, Kumaun Unviersity, Nainital. 442 p 41. Rice EL (1984) Allelopathy. Second29. Mehar N, Uzuna S, Khan MA (1995) Edition. Orlando, Florida: Academic Press. Allelopathic effects of P. juliflora Swartz. J 422 pp Arid Environ 31(1): 83-90 42. Rice EL (1986) Allelopathic growth30. Newman EI (1978) Allelopathy: Adaptation stimulation. In: Putnam AR, Tang CS (eds) or accident? In: Harborne JB (ed) 832 | P a g e
    • Rajan Katoch, Anita Singh, Neelam Thakur/ International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.828-834 The Science of Allelopathy, New York. pruning on maize and cowpea seedlings. John Wiley and Sons Agrofor Syst 26(3): 249-254 43. Rizvi SJH, Rizvi V (1987) Improving crop 50. Wei Q, Zeng RS, Kong CH, Lu SM, Zeng productivity in India. Role of Q, Tang HF (1997) The isolation and Allelochemicals. In: Waller GR (ed) identification of allelochemicals from aerial Allelochemicals: Role in Agriculture and parts of tropical Ageratum. Acta Forestry. ACS Symposium Series 330, pp Phytoecologica Sinica 21: 360-366 69-75 51. Wilson RE, Rice EL (1968) Allelopathy as 44. Shaukat SS, Ghazala P, Khan D, Ahmed M expressed by Helianthus annuus L. and its (1985) Phytotoxic effects of Citrullus role in old-field succession. Bull Torrey Bot colocynthis L., Schard on certain crop Club 95: 432-448 plants. Pak J Bot 17: 235-246 52. Xuan TD, Shinkichi T, Hong NH, Khanh 45. Shaukat SS, Tajuddin Z, Siddiqui IA (2003) TD, Min CI (2004) Assessment of Allelopathic potential of Launaea phytotoxic action of Ageratum conyzoides L. procumbens (Roxb.) Rammaya and (billy goat weed) on weeds. Crop Prot 23: Rajgopal: A tropical weed. Pak J Biol Sci 915-922 6(3): 225-230 53. Zhao X, Zheng G, Niu X, Li W, Wang F, Li 46. Singh CM, Angiras NN, Singh SD (1988) S (2009) Terpenes from Eupatorium Allelopathic effects of root exudates from adenophorum and their allelopathic effects obnoxious weed Parthenium hysterophorus on Arabidopsis seeds germination. J Agric L. Ind J Weed Sci 20(1): 18-22 Food Chem 57(2):478-482 47. Singh HP, Batish DR, Kaur S, Kohli RK (2003) Phytotoxic interference of Ageratum conyzoides with wheat (Triticum aestivum). J Agron Crop Sci 189:341–346 48. Stowe LG (1979) Allelopathy and its influence on the distribution of plants in an Illinois old field. J Ecol 67: 1065-1085 49. Tian G, Kang BT (1994) Evaluation of phytotoxic effects of G. sepium (Jacq) WalpTable 1: Effect of decaying residue of E. adenophorum, A. conyzoides and L. camara in soil on the germination per cent of test crops (on seventh day post-sowing) and weight of shoot and root of test crops (on fourteenth day post-sowing) Germination (%) Shoot weight (g) Root weight (g)S.No. Treatment Wheat Paddy Maize* Wheat Paddy Maize* Wheat Paddy Maize1. T0M 73.30b 96.7a 96.7 0.101b 0.036ab 0.95 0.011de 0.021d 0.356d a2. T1E5 100.00 96.7a 96.7 0.143 a 0.030b 1.07 0.046a 0.027bc 0.406d d3. T1E10 36.70 43.3c 70.0 0.047 c 0.027b 1.31 0.028bc 0.023d 0.384d e4. T2A5 13.30 86.7a 83.3 0.052 c 0.045a 1.19 0.027bc 0.029ab 0.537c e5. T2A10 00.0 60.0b 83.3 0.00d 0.033b 1.16 0.000 e 0.027bc 0.518c c6. T3L5 53.3 86.7a 83.3 0.139 a 0.032b 1.36 0.034b 0.026c 0.588b cd7. T3L10 46.7 26.7d 80.0 0.136 a 0.028b 1.15 0.022 cd 0.030a 0.762aGM 46.19 70.97 84.76 0.088 0.033 1.17 0.024 0.026 0.507F value 52.40 40.78 2.42 31.84 4.201 1.72 20.73 18.37 76.01S.E. 6.67 6.17 - 0.014 0.004 - 0.005 0.001 0.023C.D. (5%) 14.31 13.23 - 0.030 0.009 - 0.011 0.002 0.049Data were subjected to analysis of variance (ANOVA)/ *Duncan’s multiple range test (DMRT)Values with different superscripts in each column are significantly different at p≤0.05. Non-significant data arerepresented by N.S. 833 | P a g e
    • Rajan Katoch, Anita Singh, Neelam Thakur/ International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.828-834Table 2: Effect of decaying residue of E. adenophorum, A. conyzoides and L. camara in soil on the shoot lengthof test crops on seventh and fourteenth days after sowing Shoot length (cm) S.No. Treatment On seventh day On fourteenth day Wheat Paddy Maize Wheat Paddy Maize 1. T0M 20.4a 5.63a 19.4a 22.9a 21.4a 37.1ab c c bc a 2. T1E5 13.4 2.63 11.8 22.6 16.1c 37.0ab d c bc b 3. T1E10 2.57 2.40 10.2 7.00 13.4d 29.9c d ab c b 4. T2A5 4.07 4.20 9.83 6.97 19.0b 38.1ab e bc bc c 5. T2A10 0.00 2.97 12.3 0.00 13.7d 34.5bc b c b a 6. T3L5 16.8 2.33 13.6 23.4 16.0c 39.5a b bc c a 7. T3L10 15.4 3.13 9.40 21.9 16.2c 37.3ab GM 10.38 3.33 12.36 14.97 16.54 36.2 F value 162.2 5.481 8.179 318.3 25.46 4.869 S.E. 0.89 0.72 1.70 0.79 0.79 2.03 C.D. (5%) 1.91 1.54 3.65 1.69 1.69 4.35Data were subjected to analysis of variance (ANOVA) and values with different superscripts in each column aresignificantly different at p≤0.05. 834 | P a g e