| | | International Symposium on Allelopathy in Sustainable Agriculture, Forestry and Environment. | India. | September 6-8, 1994. New Delhi, | Lecturer | |
| | Qasem, J.R. and B. E. Abu-Irmaileh | First Scientific Meeting of Arab Society for Plant Protection | Jordan | November, 22-25, 1982 | Lecturer | |
| | | Fifth Arab Congress of Plant Protection. | Morocco. | November 27- December 2, 1994. | Lecturer | |
| | | 7th Arab Plant Protection Congress, | Syria, Damascus. | November 2006 | Lecturer | |
| | | 7th Arab Plant Protection Congress, . | Syria , Damascus | November 2006 | Lecturer | |
| | | 15th International Plant Protection Congress, The First Gathering for Plant Protection in the 21st Century. | China, Beijing,. | May 11-16, 2004 | Lecturer | |
| | | 16th European Weed Research Society Symposium | Turkey | June 23-27, 2013 | Lecturer | |
| | | Amman Capital Municipality, Department of Gardens. Workshop on Wild Flowers and Herbs. | Jordan | June 16, 1997 | Lecturer | |
| | | Fourth Jordanian Scientific Week. | Jordan. | August 28 September, 4, 1996. Amman | Lecturer | |
| | | 22nd Asian-Pacific Weed Science Society Conference | Pakistan | 8-12 March 2010 | Lecturer | |
| | | 10th World Congress on Parasitic Weeds. | Turkey, Kusadasi | 8-12 June 2009 | Lecturer | |
| | | The First Arab Congress on Medicinal Plants as Clinical Drugs Based on the Recent Scientific Methods | Syria. | 5-8 October, 1992 | Lecturer | |
| | Qasem, J. R. and T. A. Hill | First Jordanian Conference of Crop Protection | Jordan, | 3-5 October, 1989 | Lecturer | |
| | | 10th Arab Congress of Plant Protection, | Lebanon | 26-30 October, 2009 | Lecturer | |
| | | The Second Arab Congress on Plants and Medicinal Herbs in the Arab World | Sudan | 25-27 November, 1997. Khartoum | Lecturer | |
| | | | USA, Biloxi, MS. | 25 Jan 2001 | Lecturer | |
| | | | Canada. | 23-27 June 2008, Vancouver, Abstract no. 191 page 75. | Lecturer | |
| | | | Canada | 23-27 June 2008, Vancouver, . Abstract no. 193 page 75 | Lecturer | |
| | | | Canada, Vancouver, | 23-27 June 2008, . Abstract no. 216. page 85. | Lecturer | |
| | | Seventh Arab Congress of Plant Protection. | Jordan | 22-26 October, 2000. Amman,. Abstract no. 546. | Lecturer | |
| | | Seventh Arab Congress of Plant Protection. | Jordan, Abstract no. 248. | 22-26 October, 2000. Amman | Lecturer | |
| | | International Conference on Role of Allelopathy in Sustainable Agriculture. | Pakistan. | 22-24 March 2007, University of Arid Agriculture, Rawalpindi,. page 25-26. | Lecturer | |
| | Qasem J.R. and Issa. N.N. | the Fourth Congress on Allelopathy, | Austuralia, | 21-26 August, 2005, Charls Strurt University, Wagga Wagga, NSW,. | Lecturer | |
| | | 5th World Congress on Allelopathy, | USA | 21-25 September 2008, Saratoga Springs, New York, USA | Lecturer | |
| | | 5th World Congress on Allelopathy, | USA, New York, | 21-25 September 2008, Saratoga Springs, | Lecturer | |
| | Qasem, J.R. and Foy, C.L. | 4th International Weed Science Congress | South Africa | 20-24 June, 2004 Durban,. Page 97 | Lecturer | |
| | | 4th International Weed Science Congress | South Africa | 20-24 June 2004 Durban,. Page 98 | Lecturer | |
| | | 4th International Weed Science Congress | South Africa | 20-24 June 2004 Durban,. Page 95 | Lecturer | |
| | Tei F., Cirujeda A., Dobrzański A., R. J. Froud-, Williams Mennan H., Neuweiler R., Pannacci E., Qasem J., Rocha F., Simončič A., Verschwele . van der Weide A., Zaragoza R, C. | | Norway, Hamar, | 2007. | Lecturer | |
| | | Third World Congress on Allelopathy, | Japan, Tsukuba | 2002, | Lecturer | |
| | | Weed Science Society of America. Fortieth Meeting. | Canada. | 2000 Toronto, Abstract No. 219. | Lecturer | |
| | | Seminars Series. Old Dominion University. Norfolk, Virginia, | USA. | 2000 | Lecturer | |
| | | Second World Congress on Allelopathy, Critical Analysis & Future Prospects. | Canada 1999 Lakehead University,. Abstract no. 150. | 1999 | Lecturer | |
| | | European Weed Research Society (EWRS). Mediterranean Symposium, | France | 1998, Monteplier, | Lecturer | |
| | | Workshop of Jordan Arid Zone Productivity Project (JAZPP). JAZPP Office, | Jordan Faculty of Agriculture, University of Jordan. Amman, | 1998 | Lecturer | |
| | | Workshop of Jordan Arid Zone Productivity Project (JAZPP). JAZPP Office, | Jordan. | 1997 | Lecturer | |
| | | Workshop of Jordan Arid Zone Productivity Project (JAZPP). JAZPP Office, | Jordan | 1996 | Lecturer | |
| | | The First Arab Symposium for Weed Control in Orchards and Vegetable Fields | Jordan.11-13 October , | 1992 | Lecturer | |
| | | The Second Arab Scientific Symposium on Weed Control in Field Crops | Sudan. | 19-20 October, 1993 | Lecturer | |
| | | 1st Conference of Asian Allelopathy Society, | China, South China University, Guangzhou | 18-22 December 2009, | Lecturer | |
| | | International Workshop on Allelopathy-Current Trends and Future Applications. | Pakistan. University of Agriculture, Faisalabad, page 42. | 18-21 March 2007. | Lecturer | |
| | | First World Congress on Allelopathy , A science for the future. | Spain. Cadiz | 16-20 September, 1996. | Lecturer | |
| | | The Regional and Scientific Exhibition on the Medicinal, Aromatic and Poisnous Plants, | Republic of Yemen | 16-18 April 2007. Sana'a University,. Page 34. | Lecturer | |
| | | The 6th World Congress on Allelopathy-From Theory to Practice, South China Agriculture University, December 15-19, 2011 | China | 15-19 December 2011 | Lecturer | |
| | | Fourth Arab Congress of Plant Protection | Egypt. | 1-5 December, 1991 | Lecturer | |
| | | The First Arab Symposium for Weed Control in Orchards .and Vegetable Fields | Jordan | 11-13 October, 1992 | Lecturer | |