Four medical plants pre-treaded in the field with traditional, organic and biofertilizers as combined inoculation of some N₂-fixing and phosphate dissolving microorganisms namely fenugreek, mustard, black cumin and nostortium, each plant material have four fertilization treatments were tested against Sitophilus oryzae. All sixteen plant materials were evaluated against the insect pest to study the degree of infestation on the tested materials of the 16 tested medical plant materials, most of them exhibited more tolerance than the other remained and had the lowest numbers of pests recorded monthly as Acarina and Insecta for nearly one year. These seeds mixed with wheat grains as protectants at two levels of 1 and 10% by weight. The results obtained showed that the degree of infestation and the mean of emerged adults of S. oryzae were affected by the plant species as well as the level and the kind of fertilizers. Inoculation of bio-organo fertilizer and / or chemical fertilizer changed some physical and chemical characters of tested plant species compared with control (traditional fertilization). Therefore, the differences for susceptibility of insect infestation under the different levels and the kind of fertilizer may be due to this cause. So, the type of fertilization may have an effect on the degree of insect infestation. Pirimiphos-methyl included in the present study as a recommended chemical insecticide against stored product insects for comparison the chemical insecticide tested exhibited the  highest effect on the all studied parameters. Thus we recommend mixing wheat grains with fenugreek by the ratio of 90 : 10 to result on decrease of insect infestation without addition of chemical pesticides. Fenugreek addition to wheat grains may also improve nutritional value of the resulted flour, to shure these findlings further experiments are needed.