The objective of the experiment was to study the development of weed in the durum wheat grown under three cropping techniques, conventional, minimum and no till, after two years of implementation, in the semi arid zone of Setif. Weed seed bank has been estimated in the 0-15 and 15-30 cm soil profile as well as surface weed density. Nineteen species were identified, with a predominance of Polygonum aviculare L., Veronica hederifolia L., Chenopodium vulvaria L. and Avena sterilis. Other species, not less important, are annual dicotyledonous largely known in the region, among which Fumaria densiflora, Fumaria officinalis, Sonchus arvensis L., Papaver rhoeas L., Daucus carota L. and Bifora radiens. Monocotyledons dominated under no till with an average plant density of 57.3 plants/m 2 while the dicotyledonous dominated under shallow tillage with an average plant density of 70.5 plants/m 2. Conventional tillage was characterized by equilibrium between both weed families.
