Science International  Volume 4 Issue 3, 2016

Research Article

Allelopathic Interference of Leaf Powder and Aqueous Extracts of Hostile Weed: Parthenium hysterophorus (Asteraceae)
Tauseef Anwar
Laboratory of Weed Management, Department of Plant and Environmental Protection, PARC Institute of Advanced Studies in Agriculture (PIASA) affiliated with Khyber Pakhtunkhwa Agriculture University, Peshawar, National Agriculture Research Centre (NARC) Campus, Park Road, 44000 Islamabad, Pakistan

Shahida Khalid
Laboratory of Weed Management, Department of Plant and Environmental Protection, PARC Institute of Advanced Studies in Agriculture (PIASA) affiliated with Khyber Pakhtunkhwa Agriculture University, Peshawar, National Agriculture Research Centre (NARC) Campus, Park Road, 44000 Islamabad, Pakistan

Maimona Saeed
Laboratory of Plant Physiology, Department of Botany, Pir Mehar Ali Shah-Arid Agriculture University, Murree Road, Shamsabad, 46300 Rawalpindi, Pakistan

Roomina Mazhar
Laboratory of Plant Physiology, Department of Botany, Pir Mehar Ali Shah-Arid Agriculture University, Murree Road, Shamsabad, 46300 Rawalpindi, Pakistan

Huma Qureshi
Laboratory of Plant Physiology, Department of Botany, Pir Mehar Ali Shah-Arid Agriculture University, Murree Road, Shamsabad, 46300 Rawalpindi, Pakistan

Madiha Rashid
Department of Botany, Lahore College for Women University, Near Wapda Flats, Jail Road, 54000 Lahore, Pakistan

ABSTRACT:
Background: Allelopathy is a pragmatic approach to sustainable weed management. There is an increasing interest in exploration of plant allelopahty for weed management strategies in agro-ecosystems. Allelochemicals could be used for weed management directly or indirectly (using their chemistry) to develop new herbicides. There is a crucial need to discover new weed control technologies which will overcome limitations faced by synthetic chemicals and are eco-friendly. Allelopathy is an environment friendly and economic technique in controlling weeds. Materials and Methods: Allelopathic activity of Parthenium hysterophorus was examined against the seed growth of five test species i.e., Avena fatua, Rumex dentatus, Helianthus annuus (var., K.S.E 7777), Zea mays (var., Islamabad Gold 2010) and Triticum aestivum (var., Wafaq 2001). Two screening methods, i.e., aqueous extract method and plant sandwich method were used to investigate the allelopathic activity of P. hysterophorus to seeds and pre-germinated seeds (radicle protruded by at least 1 mm) of test species on filter paper and soil. Following three parameters were used in allelopathic screening methodologies. (a) Germination percentage (%), (b) Radicle length (cm) and (c) Plumule length (cm). The STATISTIX 9 software was used for analysis of results. Means were separated by using Fisher’s protected LSD test. Results: Results of petri plate experiment had shown greatest decrease of 87.6% in sunflower followed by Rumex dentatus 83.6%, maize 78.7%, wheat 58.2 and 26.6% Avena fatua as compared to their respective control in aqueous extract. A similar decrease was observed in radicle length of test plant species by aqueous extract in soil. Plumule length of cereals wheat and maize were more drastically affected by aqueous extract of Parthenium hysterophorus resulted 75.2 and 83.25% decrease as compared to their respective control. A significant decrease of 40, 49.37 and 52.2% was recorded in plumule length of Avenafatua, Rumex dentatus and Helianthus annuus as compared to their control plants. A considerable decrease of 93.06% was observed in radicle length of Rumex dentatus by powder extract of Parthenium hysterophorus in petri plate experiment. Radicle length of wheat and maize were greatly affected by powder extract leading to 70.2 and 76.2% decrease as compared to control plant while radicle length of Avena fatua was less affected resulting 24.8% decrease as compared to control plant. Same effects of powder extract on radicle length were recorded in soil germinated seeds. Germination of all the test species was suppressed with aqueous extracts and plant powder. Parthenium also suppressed growth of weeds at seedling stage with both type of amendments. Conclusion: Current findings provide evidence that the Parthenium hysterophorus has strong potential as allelopathic plant but according to the results it significantly decreased the germination and growth of the wheat plant. The study revealed that Parthenium employed an inhibitory effect on weed growth and can be explored as bio herbicide.
 
    How to Cite:
Tauseef Anwar, Shahida Khalid, Maimona Saeed, Roomina Mazhar, Huma Qureshi and Madiha Rashid , 2016. Allelopathic Interference of Leaf Powder and Aqueous Extracts of Hostile Weed: Parthenium hysterophorus (Asteraceae). Science International, 4: 86-93
DOI: 10.17311/sciintl.2016.86.93
 


INTRODUCTION

Release of chemicals by plants in environment and their effect on neighboring plants is an old idea known since 370 B.C.1,2. There is an increasing interest in exploration of plant allelopahty for weed management strategies in agro-ecosystems3-5. Allelochemicals could be used for weed management directly or indirectly (using their chemistry) to develop new herbicides6. The opportunity for bio herbicides is expanded by increasing herbicide resistant weeds7. Due to the manifold mechanisms involved in pathogenesis, there is a low chance of bio herbicide resistance development8. Allelopathic crops restrain growth of weeds while seed germination is inhibited by phytotoxins released from their residues. Allelochemicals with herbicidal activity from different plant species have been identified9. Most of the allelochemicals are toxic thus can be used as herbicides10. It has been reported that weeds in rice fields cause yield loss of 10-40% that occasionally reaches up to 100, 20% yield loss in sugarcane and 40% yield loss in soybean. Therefore, weeds are a big problem for farmers all over the world. There is a crucial need to discover new weed control technologies which will overcome limitations faced by synthetic chemicals and are eco-friendly. Allelopathy is an environment friendly and economic technique in controlling weeds. Allelopathic plants are source of new herbicidal compounds, the necessity of which is due to the resistance development in weeds to synthetic compounds11.

In crop defense against weeds, allelopathy is an important component. Previous reports documented decrease in growth of Avena fatua, Coronopus didymus, Chenopodium album and Phalaris minor by sunflower extract with no effect on wheat12. Fungal growth was suppressed by hexane extracts Rumex dentatus13. Rye was inhibited by Roshan cultivar of wheat due to its allelochemical nature than Tabasi, Niknejad and Shiraz14. Seed germination and seedling growth of Lactuca sativa was moderately effected by Lactuca dissecta, highly affected by Inula koelzii and Inula falconeri, while showed stimulatory effect by Anthemis nobilis15.

Parthenium hysterophorus L. is a hostile weed drastically retarding growth of neighboring species16,17. The ability of P. hysterophorus L., to displace other species is due to allelopathy18. However, its phytotoxic nature has not been exploited for pest management19,20. Tefera17 reported concentration dependent inhibitory effects of Parthenium weed extracts to seed germination and growth of Eragrostis. Under laboratory conditions, parthenin release by aqueous extraction of fresh leaf material of Parthenium hysterophorus proved to have 16-100% relative role21-24.

Experiments were designed to: (i) Explore the allelopathic potential of Parthenium hysterophorus, (ii) Investigate the response of Avena fatua, Rumex dentatus, Helianthus annuus, Triticum aestivum and Zea mays to the water extracts of Parthenium hysterophorus and (iii) Explore the efficacy of Parthenium hysterophorus against selected weeds.


MATERIALS AND METHODS

Collection and mechanical processing of plant material: Allelopathic activity of Parthenium hysterophorus was examined against the seed growth of five test species. Two screening methods, i.e., aqueous extract method and plant sandwich method were used to investigate the allelopathic activity of Parthenium hysterophorus to seeds and pre-germinated seeds (radicle protruded by at least 1 mm) of test species, on filter paper and soil. Fresh leaves of Parthenium hysterophorus were collected from different locations of district Rawalpindi, Punjab, Pakistan and thoroughly washed under running tap water. The dried plant material was crushed, ground to fine powder and kept at 4°C in air tight plastic zip lock bags25-28.

Procurement of seeds of test species: Seeds of Avena fatua, Rumex dentatus, Helianthus annuus (var., K.S.E 7777), Zea mays (var., Islamabad Gold 2010) and Triticum aestivum (var., Wafaq 2001) were procured from Department of Crop Science, National Agriculture Research Centre, Islamabad.

Sterilization of seeds of test species: Seeds of test species were sterilized with 1% sodium hypochlorite for 2 min, washed with distilled water and used for further bioassay studies29.

Preparation of aqueous extract: A stock solution was prepared by soaking 10 g of dried powder in 200 mL water in a flask. It was agitated along an orbital shaker (150 rpm) for 24 h at room temperature. The extract was strained through a muslin cloth and filtered through Whatman filter paper No. 1. The extract was stored in pre-sterilized flasks at 4°C. The extracts were used within 3-4 days to avoid prospective chemical alterations and contamination30.

Bioassay parameters: Following three parameters were used in allelopathic screening methodologies. (i) Germination percentage (%), (ii) Radicle length (cm) and (iii) Plumule length (cm).

Aqueous extract bioassay: This method was used to check the growth inhibition effects of leaf extracts of Parthenium hysterophorus. Five replicates were used in Completely Randomized Designed (CRD). Ten surface sterilized seeds of each test species were placed to each petri plate. The glass petri dishes (9 cm) were tape sealed, covered with aluminum foil and incubated in the growth chamber at room temperature (25°C) for 15 days. The germination was recorded on a daily basis. The results were analyzed by counting the number of germinated seeds. Later on this period, the dishes were observed and studied for parameters. The three parameters of the test species, i.e., germination percentage, radicle length (cm) and plumule length (cm) were recorded after 15 days with reference to the control31. Screening of both seeds and pre-germinated seeds were carried out on filter paper and soil, separately.

Screening on filter paper: A filter paper was placed in a glass petri dish (9 cm). Five milliliters leaf extract of leaf extract of Parthenium hysterophorus was poured with the help of the pipette into petri dishes underlain with filter paper. Five milliliters distilled water was used in petri dishes as a control.

Screening on soil: A measured quantity of 25 g of soil was placed in a glass petri dish (9 cm). Fifteen milliliters leaf extract of Parthenium hysterophorus was poured with the help of the pipette into petri dishes underlain with soil. Fifteen milliliters distilled water was used in petri dishes as a control.

Plant leaf powder bioassay: This method was used to inspect the growth inhibition effects of Parthenium hysterophorus. Five replicates were used in Completely Randomized Designed (CRD). Ten surface sterilized seeds of test species were placed in each petri plate. Glass petri dishes were squash tape sealed, covered with aluminum foil and incubated in the growth chamber at room temperature for 15 days. The germination was recorded on daily basis. The results were analyzed by counting the number of germinated seeds (in case of seed). After this period, the dishes were observed and studied for parameters. Three parameters of the test species i.e., germination percentage, plumule length (cm) and radicle length (cm) were recorded after 15 days with reference to control31. Screening of both seeds and pre-germinated seeds carried out on filter paper and soil, separately.

Screening on filter paper: A filter paper was placed in a glass petri plate (9 cm). A measured quantity 0.25 g of Parthenium hysterophorus was added to filter paper along with 5 mL distilled water was poured with the help of pipette into petri dishes per petri dish. Five milliliters distilled water was used in petri dishes as control without adding leaf powder on filter paper.

Screening on soil: A filter paper was placed in a glass petri plate (9 cm). A measured quantity 0.25 g of Parthenium hysterophorus was added to 25 g soil with 15 mL distilled water by pipette into each petri plate. Fifteen milliliters distilled water was used in petri dishes as control without adding leaf powder on soil.

Statistical analysis: The STATISTIX 9 software was used for analysis of results. Means were separated by using Fisher’s protected LSD test32.


RESULTS AND DISCUSSION

Effect of Parthenium hysterophorus extract and powder on germination percentage of test species: The results revealed that the Parthenium aqueous extract adversely inhibited the germination of all the tested plant species. The germination percentage of Rumex dentatus was significantly reduced due to application of aqueous extract. In cereals, extreme reduction in wheat seeds was recorded with the application of Parthenium aqueous extract. Similar results were obtained in soil condition. While in case of powder extract the germination percentage was decreased in petri plate as well as in soil. The germination of Rumex dentatus remained most affected with the application of Parthenium extract. However, the growth of Helianthus seeds almost or nearly remained unaffected as compared to the respective control. It was clear from the study that Parthenium exhibited an inhibitory effect on the germination and growth of the test species (Table 1). The growth repressive effects of Parthenium hysterophorus L., on germination of other crops have been reported18,33,34. Allelopathic nature of Parthenium has been reported by other researchers35-40. Root extracts of Parthenium reduced the germination and growth of barley and maize41. Similarly, germination and growth of Eragrostis decreased with increasing concentration of Parthenium extracts17. Parthenium residues show high degree of phytotoxicity35,38-40,42,43 largely attributed to water-soluble allelochemicals parthenin16,44. Water-soluble allelochemicals particularly parthenin have been identified from various parts of the weed16,45 and is believed to play role in allelopathic interference with neighboring plants7,21,46.

Table 1: Germination percentage of seeds of test species in aqueous extract and leaf dry powder of Parthenium hysterophorus in filter papers and soil

Table 2: Radical length (cm) of seeds and pre-germinated seeds of test species in aqueous extract of Parthenium hysterophorus in filter papers and soil

Effect of Parthenium hysterophorus aqueous extract on radicle and plumule length of test species: Aqueous extract of Parthenium hysterophorus significantly reduced the radicle length of germinated seeds of test species. Results of petri plate experiment had shown greatest decrease of 87.6% in sunflower followed by Rumex dentatus 83.6%, maize 78.7%, wheat 58.2 and 26.6% Avena fatua as compared to their respective control. A similar decrease was observed in radicle length of test plant species by aqueous extract in soil (Table 2). Plumule length of cereals wheat and maize were more drastically affected by aqueous extract of Parthenium hysterophorus resulted 75.2 and 83.25% decrease as compared to their respective control. A significant decrease of 40, 49.37 and 52.2% was recorded in plumule length of Avena fatua, Rumex dentatus and Helianthus annuus as compared to their control plants. A similar trend was observed in soil germinated seeds of test plant species (Table 3). Pandey47 stated that parthenin inhibited growth of water hyacinth by various physiological changes brought about by loss of dehydrogenase activity in roots, damage of cellular membrane and loss of chlorophyll in the leaves. Batish et al.48 reported that parthenin impaired mung bean growth by affecting protease and peroxidase enzyme activities, respiration and protein content. It was also concluded that parthenin effected more the growth of radicle than plumule.

Table 3: Plumule length (cm) of seeds and pre-germinated seeds of test species in aqueous extract of Parthenium hysterophorus in filter papers and soil

Table 4: Radical length (cm) of seeds and pre-germinated seeds of test species in leaf dry powder of Parthenium hysterophorus in filter papers and soil

Various phenolic compounds including ferulic, caffeic, chlorogenic, vanillic and anisic acid identified in Parthenium are probably growth retardants of test crops in amended soils39,40,45,49,50.

Effect of Parthenium hysterophorus powder on radicle and plumule length of test species: A considerable decrease of 93.06% was observed in radicle length of Rumex dentatus by powder extract of Parthenium hysterophorus in petri plate experiment. Radicle length of wheat and maize were greatly affected by powder extract leading to 70.2 and 76.2% decrease as compared to control plant while radicle length of Avena fatua was less affected resulting 24.8% decrease as compared to control plant. Same effects of powder extract on radicle length were recorded in soil germinated seeds (Table 4, 5). Parthenin released by aqueous extraction of P. hysterophorus fresh leaf material under laboratory conditions proved to pay a relative role of 61-100% to overall phytotoxic effects21,51,52. Srivastava et al.53 stated that aqueous extracts of inflorescence and leaves retarded the germination and seedling growth of wheat, peas and barley. Kohli et al.35 proposed that two synergistically acting allelochemicals were responsible for retardation in seed germination and seedling growth of cabbage, when grown in inflorescence and leaf leachates from Parthenium.

Table 5: Plumule length (cm) of seeds and pre-germinated seeds of test species in leaf dry powder of Parthenium hysterophorus in filter papers and soil


CONCLUSION AND FUTURE RECOMMENDATIONS

Current findings provide evidence that the Parthenium hysterophorus has strong potential as allelopathic plant but according to the results it significantly decreased the germination and growth of the wheat plant. The findings verified that under laboratory conditions, Parthenium is among one of the inhibitors for residue allelopathy by retarding germination and decreasing seedling growth. However, observed hermetic effects propose possible implications for interference of Parthenium hysterophorus in a natural plant community rely on accretion and the stability of parthenin in soil.


REFERENCES

  1. Willis, R.J., 1985. The historical bases of the concept of allelopathy. J. History Biol., 18: 71-102

  2. Willis, R.J., 1997. The history of allelopathy. 2. The second phase (1900-1920), the era of S.U. Pickering and the USDA Bureau of soils. Allelopathy J., 4: 7-55.

  3. Anwar, T., Y. Arafat and S. Khalid, 2010. Response of maize and sunflower to different allelopathic plants. Proceedings of the International Conference on Biodiversity is our Life Centre for Biodiversity and Conservation, December 28-31, 2010, Shah Abdul Latif University, Khairpur -.

  4. Anwar, T., Y. Arafat and S. Khalid, 2011. The effect of different plant extracts and plant residues on wheat (Triticum aestivum L.) and wild oat (Avena fatua L.). Proceedings of the 3rd International Weed Science Conference, September 6-8, 2011, Khyber Pakhtunkhwa Agricultural University, Peshawar -.

  5. Weston, L.A., 1996. Utilization of allelopathy for weed management in agroecosystems. Agron. J., 88: 860-866

  6. Duke, S.O., F.E. Dayan, J.G. Romagni and A.N. Rimando, 2000. Natural products as sources of herbicides: Current status and future trends. Weed Res., 40: 99-111

  7. Riaz, S., S. Khalid, R. Chatta, S. Sadia, Y. Arafat and T. Anwar, 2012. Weed management by Cuscuta L. (parasitic plant). Proceedings of the 12th National and 3rd International Conference of Botany, September 1-3, 2012, At Quaid‐i‐Azam University, Islamabad, Pakistan -.

  8. Auld, B.A. and L. Morin, 1995. Constraints in the development of bioherbicides. Weed Technol., 9: 638-652

  9. Bhadoria, P.B.S., 2011. Allelopathy: A natural way towards weed management. Am. J. Exp. Agric., 1: 7-20

  10. Troc, M., D. Saja, A. Kornas, A. Zuraw and A. Skoczowski, 2011. Strong endothermic effects caused by allelopathic interactions during growth of mustard, rape, wheat and clover seedlings. J. Thermal Anal. Calorimetry, 104: 141-148

  11. De Albuquerque, M.B., R.C.D. Santos, L.M. Lima, P.DAM. Filho, R.J.M.C. Nogueira, C.A.G.D. Camara and A.D.R. Ramos, 2011. Allelopathy, an alternative tool to improve cropping systems: A review. Agron Sustain. Dev., 31: 379-395

  12. Naseem, M., M. Aslam, M. Ansar and M. Azhar, 2009. Allelopathic effects of sunflower water extract on weed control and wheat productivity. Pak. J. Weed Sci. Res., 15: 107-116.

  13. Fatima, N., M. Zia, Riaz-ur-Rehman, Z.F. Rizvi, S. Ahmad, B. Mirza and M.F. Chaudhary, 2009. Biological activities of Rumex dentatus L: Evaluation of methanol and hexane extracts. Afr. J. Biotechnol., 8: 6945-6951

  14. Labbafy, M.R., F. Maighany, A. Hejazy, H. Khalaj, A.M. Baghestany, I. Allahdady and A. Mehrafarin, 2009. Study of allelopathic interaction of wheat (Triticum aestivum L.) and rye (Secale cereal L.) using equal-compartment-agar method. Asian J. Agric. Sci., 1: 25-28

  15. Khan, A.L., M. Hamayun, J. Hussain, H. Khan and S.A. Gilani et al., 2009. Assessment of allelopathic potential of selected medicinal plants of Pakistan. Afr. J. Biotechnol., 8: 1024-1029

  16. Picman, J. and A.K. Picman, 1984. Autotoxicity in Parthenium hysterophorus and its possible role in control of germination. Biochem. Syst. Ecol., 12: 287-292

  17. Tefera, T., 2002. Allelopathic effects of Parthenium hysterophorus extracts on seed germination and seedling growth of Eragrostis tef. J. Agron. Crop Sci., 188: 306-310

  18. Narwal, S.S., 1994. Allelopathy in Crop Production. Scientific Publishers, Jodhpur, India, pp: 145.

  19. Datta, S. and D.B. Saxena, 2001. Pesticidal properties of parthenin (from Parthenium hysterophorus) and related compounds. Pest Manage. Sci., 57: 95-101

  20. Batish, D.R., R.K. Kohli, H.P. Singh and D.B. Saxena, 1997. Studies on herbicidal activity of parthenin, a constituent of Parthenium hysterophorus, towards billgoat weed (Ageratum conyzoides). Curr. Sci., 73: 369-371

  21. Belz, R.G., C.F. Reinhardt, L.C. Foxcroft and K. Hurle, 2007. Residue allelopathy in Parthenium hysterophorus L.-Does parthenin play a leading role?. Crop Prot., 26: 237-245

  22. Anwar, T., S. Khalid, Y. Arafat, S. Sadia and S. Riaz, 2012. Management of Avena fatua L. and Rumex dentatus L., in associated crops with plant extracts. Proceedings of the 12th National and 3rd International Conference of Botany, September 1-3, 2012, Quaid-e-Azam University, Islamabad -.

  23. Anwar, T., S. Khalid, Y. Arafat, S. Sadia and S. Riaz, 2012. Allelopathic suppression of Avena fatua L. and Rumex dentatus L., in associated crops with plant leaf powders. Proceedings of the 2nd International Conference of Asian Allelopathy Society on the Topic Allelopathy: A Multi-Faceted Process, December 14-18, 2012, Chandigarh, India -.

  24. Anwar, T., S. Khalid, Y. Arafat, S. Sadia and S. Riaz, 2012. Euphorbia helioscopia L., as a source of bio-herbicide. Proceedings of the 4th International Weed Science Conference, September 6-8, 2012, Peshawar -.

  25. Hegab, M.M., S.E.A. Khodary, O. Hammouda and H.R. Ghareib, 2008. Autotoxicity of chard and its allelopathic potentiality on germination and some metabolic activities associated with growth of wheat seedlings. Afr. J. Biotechnol., 7: 884-892

  26. Jafariehyazdi, E. and F. Javidfar, 2011. Comparison of allelopathic effects of some Brassica species in two growth stages on germination and growth of sunflower. Plant Soil Environ., 57: 52-56

  27. Anwar, T. and S. Khalid, 2012. Effect of leaf powder of Rumex dentatus L., Euphorbia helioscopia L., Parthenium hysterophorus L. and Carica papaya L. on Avena fatua L., R. Dentatus, Helianthus annuus (L.), Triticum aestivum L. and Zea mays L. Proceedings of the 4th International Weed Science Conference, September 6-8, 2012, Peshawar -.

  28. Anwar, T. and S. Khalid, 2012. Effect of leaf powder of Euphorbia helioscopia L. and Parthenium hysterophorus L. on Avena fatua L., R. Dentatus, Helianthus annuus (L.), Triticum aestivum L. and Zea mays L. Proceedings of the 1st National Conference on Poverty Alleviation Through Sustainable Management of Plant Diversity, April 18-20, 2012, University of Swat -.

  29. Anwar, T. and S. Khalid, 2012. Management of Avena fatua L., Rumex dentatus L., Helianthus annuus L., Triticum aestivum L. and Zea mays L. By exploiting Carica papaya L. allelopathy, as bio-herbicide. Proceedings of the 2nd International Conference of Asian Allelopathy Society Allelopathy: A Multi-Faceted Process, December 14-18, 2012, Chandigarh, India -.

  30. Anwar, T., S. Khalid, Y. Arafat, S. Sadia and S. Riaz, 2013. Allelopathic suppression of Avena fatua and Rumex dentatus in associated crops. Pak. J. Weed Sci. Res., 19: 31-43

  31. Nasir, H., Z. Iqbal, S. Hiradate and Y. Fujii, 2005. Allelopathic potential of Robinia pseudo-acacia L. J. Chem. Ecol., 31: 2179-2192

  32. Steel, R.G.D., J.H. Torrie and D.A. Dickey, 1997. Principles and Procedures of Statistics. A Biometrical Approach. 3rd Edn., McGraw Hill Book Co., New York, pp: 172-177.

  33. Anwar, T. and S. Khalid, 2016. Allelopathic effect of Euphorbia helioscopia on Avena fatua, Rumex dentatus, Helianthus annuus, Zea mays and Triticum aestivum. Proceedings of the 13th National Weed Science Congress of Weed Science Society of Pakistan, August 19-21, 2016, Shaheed Benazir Bhutto University, Sheringal, Pakistan. -.

  34. Anwar, T. and S. Khalid, 2016. Allelopathic potential of aqueous extracts of some selected speciesto overcome weed infestation in Triticum aestivum, Zea mays and Helianthus annuus. Proceedings of the 13th National Weed Science Congress of Weed Science Society of Pakistan, August 19-21, 2016, Shaheed Benazir Bhutto University, Sheringal, Pakistan. -.

  35. Kohli, K. and D.R. Batish, 1994. Exhibition of allelopathy by Parthenium hysterophorus L. in agroecosystems. Trop. Ecol., 35: 295-307.

  36. Kohli, R.K., D. Rani, H.P. Singh and S. Kumar, 1997. Response of crop seeds towards the leaf leachates of Parthenium hysterophorus L. Indian J. Weed Sci., 28: 104-106

  37. Kumari, A. and R.K. Kohli, 1987. Autotoxicity of ragweed parthenium (Parthenium hysterophorus). Weed Sci., 35: 629-632

  38. Mersie, W. and M. Singh, 1987. Allelopathic effect of parthenium (Parthenium hysterophorus L.) extract and residue on some agronomic crops and weeds. J. Chem. Ecol., 13: 1739-1747

  39. Kanchan, S.D. and Jayachandra, 1980. Allelopathic effects of Parthenium hysterophorus L. Part IV. Identification of inhibitors. Plant Soil, 55: 67-75

  40. Kanchan, S.D. and Jayachandra, 1980. Allelopathic effects of Parthenium hysterophorus L. Part II. Leaching of inhibitors from aerial vegetative parts. Plant Soil, 55: 61-66

  41. Rashid, H., M.A. Khan, A. Amin, K. Nawab, N. Hussain and P.K. Bhowmik, 2008. Effect of Parthenium hysterophorus L. root extracts on seed germination and growth of maize and barley. Am. J. Plant Sci. Biotechnol., 2: 51-55

  42. Anwar, T. and S. Khalid, 2016. Allelopathic effect of Carica Papaya on Avena fatua, Rumex dentatus, Helianthus annuus, Zea mays and Triticum aestivum. Proceedings of the 13th National Weed Science Congress of Weed Science Society of Pakistan. August 19-21, 2016, Shaheed Benazir Bhutto University, Sheringal, Pakistan. -.

  43. Anwar, T. and S. Khalid, 2016. Allelopathic effect of Rumex Dentatus on Avena fatua, Rumex dentatus, Helianthus annuus, Zea mays and Triticum aestivum. Proceedings of the 13th National Weed Science Congress of Weed Science Society of Pakistan, August 19-21, 2016, Shaheed Benazir Bhutto University, Sheringal, Pakistan -.

  44. Mersie, W. and M. Singh, 1988. Effects of phenolic acids and ragweed Parthenium (Parthenium hysterophorus) extracts on tomato (Lycopersicon esculentum) growth and nutrient and chlorophyll content. Weed Sci., 36: 278-281

  45. Kanchan, S.D., 1975. Growth inhibitors from Parthenium hysterophorus Linn. Curr. Sci.

  46. Sadia, S., S. Khalid R. Qureshi S. Riaz, Y. Arafat and T. Anwar, 2012. Allelopathic interaction of Tagetes minuta L. An environmentally Safe bio-herbicide. Proceedings of the 12th National and 3rd International Conference of Botany, September 1-3, 2012, At Quaid‐i‐Azam University, Islamabad, Pakistan -.

  47. Pandey, D.K., 1996. Phytotoxicity of sesquiterpene lactone parthenin on aquatic weeds. J. Chem. Ecol., 22: 151-160

  48. Batish, D.R., H.P. Singh, R.K. Kohli, D.B. Saxena and S. Kaur, 2002. Allelopathic effects of parthenin against two weedy species, Avena fatua and Bidens pilosa. Environ. Exp. Bot., 47: 149-155

  49. Anwar, T., S. Khalid, M. Saeed and R. Mazhar, 2016. Allelopathic effect of Parthenium hysterophorus on Avena fatua, Rumex dentatus, Helianthus annuus, Zea mays and Triticum aestivum. Proceedings of the 13th National Weed Science Congress of Weed Science Society of Pakistan, August 19-21, 2016, Shaheed Benazir Bhutto University, Sheringal, Pakistan -.

  50. Khalid, S., Y. Arafat, T. Anwar and M.W. Aslam, 2010. Management of weeds with potentially allelopathic plants for organic agriculture. Proceedings of the International Science Conference on Utilization of Modern Agriculture Technology in Changing Environmental Perspectives, July 21-23, 2010, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan -.

  51. Arafat, Y., S. Khalid, T. Anwar, and M.R. Chatta, 2011. Management of Avena fatua with water extracts and plant residues of plants from Dargai Malakand. Proceedings of the 3rd International Weed Science Conference, April 18-20, 2011, Khyber Pakhtunkhwa Agricultural University, Peshawar -.

  52. Arafat, Y., T. Anwar, S. Khalid, S. Sadia and S. Riaz, 2012. Salvia moorcroftiana wall. Ex benth. Extract and residue is synergistic to wheatcrop and antagonistic to its associated weeds Avena fatua L., Euphorbia helioscopia L. Proceedings of the 4th International Weed Science Conference, September 6-8, 2012, Khyber Pakhtunkhwa Agricultural University, Peshawar -.

  53. Srivastava, J.N., J.P. Shukla and R.C. Srivastava, 1985. Effect of Parthenium hysterophorus Linn. Extract on the seed germination and seedling growth of barley, pea and wheat. Acta Botanica Indica, 13: 194-197.
 
 

 
Science International © 2017