Metode Penarikan Contoh untuk Pendugaan Populasi Hama Polong pada Tanaman Kedelai

Abstract

Simple random sampling, random sampling on diagonal (diagonal I ) five group sampling on diagonal (diagonal 11), and two dimensional systematic sampling techniques were applied on two soybean populations. The plot size of each population is 15 m x 20 m with density of 125,000 plants per ha, located at Jenggawah - East Java, planted in 1982. Larva of EtieZZa zinckeneZZa Tr. on every single plant was counted a f t e r seven weeks of planting on one population and after nine weeks on the other population. The unit of sampling is a single plant. The dispersion of larva E. zinckeneZZa seemed t o perform c l u s t e r r a t h e r than at random, since the simple random sampling shown to be the most i n e f f i c i e n t technique. The usual diagonal I1 sampling technique was f a i r l y good, although was not as good as the diagonal I technique, and the most e f f i c i e n t was the two dimensional systematic sampling technique. The r e s u l t s held true eventhough the sample size was changed from 25 plants t o 80 plants per 300 m2.