Abstract:In order to study the effects of soil environment on parasitism and growth of sunflower broomrape (Orobanche cernua), we used sunflower variety “Longshikui No.2”, which is high sensitive to sunflower broomrape, as test material and carried out method of inoculating and indoor culture. The results showed that: (1) soil texture had a significant effect on the parasitism of sunflower broomrape. When cultured for 50 days, the number of unearthed broomrape in sandy loam, loam and clay were 32.2, 19.5 and 4.6, respectively and the average parasite of individual plants was 38.8, 24.0 and 8.2, respectively. It showed that the sandy loam with good permeability was beneficial to the formation and growth of broomrape tumor. (2) Under the condition of sandy loam, with the increase of treatment temperature, both the number of unearthed and the number of parasitic quantities increased first and then decreased. When the incubation temperature was 25 ℃ and 30 ℃, the sunflower broomrape had higher parasitic quantities and growth speed and the number of unearthed broomrape and the average parasite of individual plants was 30.4, 31.6, 39.8 and 39.4, respectively. (3) Under the condition of sandy loam, with the increase of soil moisture, the number of unearthed and the number of parasitic quantities firstly increased and then decreased. The numbers were relatively high when soil moisture was 60% and 70%, the number of unearthed broomrape and the average parasite of individual plants were 32.6, 30.9, 39.9 and 40.9, respectively, but the number of parasites decreased significantly under high humidity condition. (4) Under the condition of sandy loam, with the increase of soil pH value, the number of unearthed and the number of parasitic quantities also increased firstly and then decreased, and reached the maximum when the soil pH was 8, the numbers of unearthed and the number of parasitic quantities was 47.5 and 51.1, respectively. There is a high number of parasites in the alkaline soil environment. The study found that sandy loam soil type, soil temperature 25~30 ℃, soil moisture 60%~70% and soil pH 8 is beneficial to the parasitism and growth of sunflower broomrape. Therefore, in order to reduce the harm of broomrape, sunflower should be planted in non neutral or acidic nonsandy soil plots, and attention should be paid to adjusting the sowing date and controlling the amount of irrigation in the field.