The parasitic weed Orobanche spp. cause severe damage to vegetables and field crops. Most of the damage caused to the crops is during the underground, not observable parasitism stage. The purpose of this study was to develop an in-situ, non-destructive method for observation and monitoring of the underground developmental stages of the root parasite O. cumana. Sunflower plants (Hellianthus annuus cv. Adi) were planted in soil artificially inoculated soil with O. cumana seeds. Clear Plexiglas minirhizotron observation plastic tubes were inserted into the soil. Seed germination, early stage of penetration, and formation of tubercles and spikes were observed non-distractively and monitored throughout the growing season by mean of minirhizotron camera. Use of this technology enabled the complete individual parasite life cycle (from germination to O. cumana shoot) to be monitored. In addition, effect of the systemic herbicide Cadre (imazapic, 480 a.i. g l-1) on the development of O. cumana was inspected and quantified. This novel methodology enables to study in-situ major aspects related to the host-parasite interaction and parasite suppression such as parasitism dynamics growth rate and the effect of chemical treatments on the parasite.