Abstract: An interlaced survey was conducted to investigate the occurrence of kiwifruit canker disease in kiwifruit orchards at different altitudes（high altitude, middle altitude and low altitude） in northern Sichuan. The spatial distribution pattern of the disease was determined by classical aggregation index method and regression analysis method. The results showed that kiwifruit canker disease plants at different altitudes were aggregated in the field, and the basic distribution form was individual population. The optimum theoretical sampling number and sequential sampling number for field sampling of kiwifruit canker disease at different altitudes were calculated, and the optimum sampling square size was determined.

Key words: kiwifruit canker, spatial pattern, sampling technique, different altitudes