The herbicidal effect of Solid Olive processing waste (SOPW) on some weed species in sunflower and wheat was investigated under greenhouse conditions at DesertResearchCenter – Cairo, Egypt, between 2010 and 2011. Solid Olive processing waste (SOPW) placed in pots (25 cm×18 cm×10 cm) in doses of 0, 3, 4.5 and 6 kg/ m2, these doses were mixed into soil (0-10 cm depth). In this experiment, 25 seeds each of Mallow (Malava sylvestris), Purslane (Portulaca oleracea), Phalaris (Phalaris minor) and Barnyard grass (Echinochloa crus-galli) besides to ten seeds of sunflower or wheat were sown in pots.
Seedlings of both weeds and crop plants were counted in order to assess the effects of Solid Olive processing waste (SOPW) on weed species and crops plant growth.
The results showed that SOPW reduction in total weed species with sunflower by 76.10, 78.70, 64.50 and 65.80 % & 96.10, 95.30, 83.50 and 85.20 % atdoses of 4.5 and 6 kg/ m2, with all weeds above, respectively. Also with wheat crop, the percentage weeds controlwere84.3, 79.5, 74.2 and 71.8 % & 96.6, 94.6, 84.7 and 82.5 % with same doses and weed species, respectively.
Solid Olive processing waste showed no toxic effects on sunflower, while wheat was affected in the initial stage but no adverse effect was detected at another growth stages.
The herbicidal effect of Olive processing waste may be considered as an safe alternative instead of chemical control which pollute the environment in some important summer crops (sunflower) and for weeds control in winter wheat.