Frequency Distribution of Citrus Rust Mite (Acari: Eriophyidae) Damage on Fruit in ‘Hamlin’ Orange Trees
作者:
Y. Yang,
J. C. Allen,
J. L. Knapp,
P. A. Stansly,
期刊:
Environmental Entomology
(OUP Available online 1995)
卷期:
Volume 24,
issue 5
页码: 1018-1023
ISSN:0046-225X
年代: 1995
DOI:10.1093/ee/24.5.1018
出版商: Oxford University Press
关键词: Phyllocoptruta oleivora;frequency distribution;yield loss model
数据来源: OUP
摘要:
Frequency distribution of the citrus rust mite,Phyllocoptruta oleivora(Ashmead), damage on ‘Hamlin’ orange,Citrus sinensisfruit was studied from 24 August to 13 October 1993, in Lake Alfred, FL. The study plot consisted of 4-yr-old Hamlin orange trees, with a north-south row OIientation. Fruit on the north quadrant of the tree were found to have the highest mean surface damage, followed by the east, south, and west quadrants. The frequency distribution of fruit surface damage changed with mean damage levels. When the mean damage was low, most of the fruit had no rust mite damage. With increasing mean fruit damage, the proportion of fruit without damage decreased, and the proportion of fruit with higher damage correspondingly increased. The resulting frequency distribution changed from an exponential decay curve to a more or less symmetrical unimodal curve, with the peak shifting toward higher damage classes as mean fruit surface damage was increased. The frequency distribution was fitted to a 2-variable logistic distribution function of mean fruit surface damage and damage class, using maximum likelihood estimation method. Fruit without rust mite damage was considered a discrete point at zero, and its relative frequency was determined as the height of the cumulative logistic at zero. The model approximated the actual data well at low mean fruit surface damage, but gave a poor fit at high mean values.
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