Some Factors Affecting the Infestation of Oriental Fruit Moth

1930 ◽  
Vol 23 (5) ◽  
pp. 813-821
Author(s):  
S. W. Frost
HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 605f-606
Author(s):  
Curt R. Rom ◽  
Donn Johnson ◽  
Mark Den Herder ◽  
Ron Talbert

Twelve apple orchards and an experimental orchard were evaluated in 2 years for weed population and diversity, primary pests (codling moth, oriental fruit moth, plum curculio and mites), primary diseases, soil water content, and 37 horticultural attributes describing tree growth, fruit growth, productivity, tree nutrition, and management intensity. Data were collected at 2 week intervals. The experimental orchard contained three apple cultivars grown in three orchard floor management systems. Increased weed ground cover related to earlier and increased mite predator populations in trees, decreased pest mite-days, but reduced tree and fruit growth. Grass weed species appeared more detrimental to tree growth than broadleaf species. Tree training intensity was negatively related to canopy density, and incidence of pests and diseases. Reductions in fruit size and quality were more closely linked to weed competition, and earliness and degree of pest mite infestation than to crop load.


1970 ◽  
Vol 102 (4) ◽  
pp. 454-471 ◽  
Author(s):  
J. H. H. Phillips ◽  
Jean R. Proctor

AbstractMethods of sampling to measure factors affecting fluctuations of a population of the Oriental fruit moth, Grapholitha molesta (Busck), on the Niagara Peninsula of Ontario were investigated from 1963 to 1967 in peach orchards in which no insecticides were used during the study. In most years females tended to be distributed evenly throughout the orchard and even at low fruit moth densities the trees were relatively evenly infested. Several sampling methods gave estimates of the numbers of larvae overwintering in the orchard only within wide limits but indicated that the numbers were probably small in all years. Eggs could be sampled but it was not practicable at the low densities of the moth in this study. No satisfactory method of sampling summer cocoons or adults was found. Destructive sampling of the larvae, in which they were removed from the trees and reared to maturity on green apples, gave the most precise estimates of numbers in each generation. The method also gave a measure of mortality, parasitism, and times and duration of each generation.


Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.


Author(s):  
Christine M. Dannels ◽  
Christopher Viney

Processing polymers from the liquid crystalline state offers several advantages compared to processing from conventional fluids. These include: better axial strength and stiffness in fibers, better planar orientation in films, lower viscosity during processing, low solidification shrinkage of injection moldings (thermotropic processing), and low thermal expansion coefficients. However, the compressive strength of the solid is disappointing. Previous efforts to improve this property have focussed on synthesizing stiffer molecules. The effect of microstructural scale has been overlooked, even though its relevance to the mechanical and physical properties of more traditional materials is well established. By analogy with the behavior of metals and ceramics, one would expect a fine microstructure (i..e. a high density of orientational defects) to be desirable.Also, because much microstructural detail in liquid crystalline polymers occurs on a scale close to the wavelength of light, light is scattered on passing through these materials.


1990 ◽  
Vol 54 (11) ◽  
pp. 638-643 ◽  
Author(s):  
PC Damiano ◽  
ER Brown ◽  
JD Johnson ◽  
JP Scheetz

1976 ◽  
Vol 7 (4) ◽  
pp. 207-219 ◽  
Author(s):  
Constance P. DesRoches

A statistical review provides analysis of four years of speech therapy services of a suburban school system which can be used for comparison with other school system programs. Included are data on the percentages of the school population enrolled in therapy, the categories of disabilities and the number of children in each category, the sex and grade-level distribution of those in therapy, and shifts in case-load selection. Factors affecting changes in case-load profiles are identified and discussed.


2019 ◽  
Vol 62 (5) ◽  
pp. 1243-1257 ◽  
Author(s):  
Peggy Pik Ki Mok ◽  
Holly Sze Ho Fung ◽  
Vivian Guo Li

Purpose Previous studies showed early production precedes late perception in Cantonese tone acquisition, contrary to the general principle that perception precedes production in child language. How tone production and perception are linked in 1st language acquisition remains largely unknown. Our study revisited the acquisition of tone in Cantonese-speaking children, exploring the possible link between production and perception in 1st language acquisition. Method One hundred eleven Cantonese-speaking children aged between 2;0 and 6;0 (years;months) and 10 adolescent reference speakers participated in tone production and perception experiments. Production materials with 30 monosyllabic words were transcribed in filtered and unfiltered conditions by 2 native judges. Perception accuracy was based on a 2-alternative forced-choice task with pictures covering all possible tone pair contrasts. Results Children's accuracy of production and perception of all the 6 Cantonese tones was still not adultlike by age 6;0. Both production and perception accuracies matured with age. A weak positive link was found between the 2 accuracies. Mother's native language contributed to children's production accuracy. Conclusions Our findings show that production and perception abilities are associated in tone acquisition. Further study is needed to explore factors affecting production accuracy in children. Supplemental Material https://doi.org/10.23641/asha.7960826


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