جستجوی مقالات مرتبط با کلیدواژه « population density » در نشریات گروه « آب و خاک »

Color sticky board traps are used in pest management for capture of adult insect, to estimate and predict population densities in later stages. Yellow sticky board traps showed high attraction for pistachio psylla. It is important to study these relationships for the right placement of traps. For each of three repetition in one year, four pistachio trees were selected randomly in one orchard. Eight traps were located on two heights and four cardinal directions of each tree (32 traps in each repetition). After one week the adult psylla captured were counted. One and two weeks 1ater, eggs and nymph densities were counted on five leaves in one of the eight positions of each tree on four other randomly selected trees (total 160 leaves each time). Data were subjected to analysis of variance. Coefficient of variation was determined between adults captured in each position and eggs and nymph density counts. There were significant differences for adult capture and egg density among directions, and in most cases significant correlations were observed between adults captured on each position and total egg and nymph density count on trees. It was concluded that for egg and nymphal density estimation, we can place traps on either of two heights and four directions except on lower east part, but preferably on either height in south direction of the trees . Also suggestions for egg and nymph sampling are given in the text.