Anotace:
For stored cereals, pest protection methods are mainly based on the use of synthetic insecticides. However, in the face of the pollution and toxicity problems associated with these insecticides, the search for other alternative solutions is essential. It is within this framework that local natural products collected in the region of Gharb, Morocco have been used to: evaluate their insecticidal effect on Sitophilus granarius (L.) and Tribolium castaneum (Herbst) the main pests of the stored cereals, and test the effect of these natural products on the germination of soft wheat seeds. Before bioassays, a survey was conducted in three representative areas in the region of Gharb to advance our understanding on the type of methods commonly used by farmers to protect the stored cereals against different pest. During our investigation, we found that 91% of respondents favor the use of synthetic insecticides and only cereals intended for self-consumption are treated with natural products. The results of the insecticidal effect of different natural products indicated that the highest mortality percentage was recorded with a concentration of 5% of Mentha pulegium powder and Capsicum frutescens. The former product induced 69 % and 57 % while the latter caused 36 % and 22 % mortality on the adults of S. granarius and T. castaneum, respectively. The germination test showed that these natural products have no effect on the germination rate of soft wheat grains. Therefore, these products can be potential alternative the synthetic insecticides for the protection of stored against pest infestation.