Integrated Weed Management by Dr. Mustapha Haidar

Dr. Mustapha Haidar, Professor of Weed Science and Director of the Advancing Research Enabling Communities Center (AREC), has been conducting both basic and applied research. His basic research is related to the field of dodder photobiology, particularly the physiological and photomorphological ecology of dodder, with the aim of addressing the physiology and biochemistry of light signal transduction. Dr. Haidar’s recent research has been applied and explores two main themes: organic weed management in no-till system or conservation agriculture, and weed seed bank dynamics in no-till and till systems.


Concerning the first theme, Dr. Haidar manages weeds using cover straw mulch in an organic farming system to control weeds without the use of pesticides. He examines strawponic (straw mulch) for managing Phelipanche aegyptiaca in potato. Strawponic is an innovative, exotic system for growing potato on soil surfaces (bare soil, turfgrass, any soft medium) using crop straw as a cover. Dr. Haidar conducted a field trial last spring/summer at AREC to test the efficacy of this system against Phelipanche aegyptiaca for small potato producers. Potato tubers were placed on bare soil surface (no cultivation) containing animal manure, covered with a blanket of crop straw, and watered through drip irrigation system. The straw was removed by hand at the end of the growing season, Phelipanche aegyptiaca infestation was estimated and potato tubers were picked up by hand. This system was found to have several benefits and positive impact: it is simple, economical (no machinery, no soil bed preparation, no digging or hilling, and suitable potato yield), sustainable (no contamination/pollution-no herbicides), water-saving, appropriate for both dry and urban areas (gardens), suitable for organic farming; moreover, it reduces P. aegyptiaca. The no-till system for potato production could be feasible in the MENA region for various reasons: cheap labor is available; it can withstand drought and water scarcity, prevalent in the region; and it provides less soil compaction, high yields, high water retention, and better biodiversity.

In the second theme, Dr. Haidar used applied research to study weed seed bank density in a seven-year-old conservation in no-till system. The significance of this work lies in the importance of weed management in implementation of new cropping systems. In Lebanon, farmers are increasingly adopting conservation agriculture (no-till) because it saves energy and reduces water and nutrient erosion. However, no-till represents a major shift in production practices and is likely to produce new weed management challenges. Thus, knowledge of soil seed banks of weeds in such systems is becoming imperative to the design of successful weed management strategies. 

The research findings revealed that the weed seed bank at a depth of 0-5cm in no-till systems is greater than that of till systems. No-till fields contained nearly seven times the density of monocot and dicot weed seeds than found in more conventional tilled fields. This branch of weed ecology helps predict the future level of weed infestation in the fields. By discovering and understanding the weed seed bank and the fate of weed seeds, a variety of management methods can be implemented to prevent, maintain, and manage weeds.

Finally, Dr. Haidar highlighted the implications of weed management research, explaining that, unlike till systems, weed seeds remain in the upper soil surface when no-till is used. This lead farmers to develop weed management strategies to reduce the number of weed seed banks in the field, as well as the potential weeds in crop growing season. This can be accomplished by managing the weed seed bank in the upper soil surface. Moreover, reducing seed rain is an important component of weed seed management: other strategies, such as using pre-emergence herbicides could be used to reduce weed seed germination or emergence, thereby enhancing the mortality of weeds. Reducing the weed seed bank is an essential component of integrated weed management strategy in various systems.​