# 고자리파리에 의한 양파피해(被害)의 포장내(圃場內) 분포양식(分布樣式)과 피해량(被害量) 추정(推定)을 위한 표본추출(標本抽出) 계획(計劃)

• Park, C.G. (Gyeongnam Provincial Office of Rural Development) ;
• Hyun, J.S. (Seoul Nat'l. Univ., College of Agriculture) ;
• Cho, D.J. (Gyeongnam Provincial Office of Rural Development) ;
• Lee, K.S. (Gyeongnam Provincial Office of Rural Development) ;
• Hah, J.K. (Gyeongnam Provincial Office of Rural Development)
• Published : 1985.04.30

#### Abstract

Every plant in $990m^2$ onion field was inspected for damages by the onion maggot. Maps were constructed every ten days to show which plants were infested and which were not from April 11 to May 21, 1984. The maps were sectioned into squares one of which contains 80 onion plants and the counts of damaged onions in each square were fitted to poisson and negative binomial distribution and tested by chi-square. We argue that the satisfactory fitness of the expected negative binomial $[P(x^2)>0.05]$ provided a useful description of the spatial distribution patterns of the damaged onions. Edge effect was tested by the differences of damage ratio and variance/mean ratio (${\sigma}^2/m$) between edge and center part. The result showed that the damage ratioes and variances of all the periods, ${\sigma}^2/m$ values after May 1 were greater in edge part than in center part. Again, the maps were sectioned into four blocks and the squares (sample units) were sectioned into quadrants. By application of the variance component technique, it was suggested that $2{\sim}8$ sample units for 5% sampling error and $1{\sim}2$ sample units for 10% error should be sampled randomly to estimate the damage ratio when $2{\sim}3$ quadrants were inspected.