An important cultural tool in the greenhouse production of tree
seedlings in the Pacific Northwest is the control of photoperiod. By
artificially lengthening the period of daily exposure to light, it is
possible to increase both the magnitude and duration of seedling
growth. By shortening the photoperiod, one can induce...
Experiments conducted in the greenhouse showed that the leafhopper,
Colladonus montanus reductus (Van Duzee), is a long-day
insect. This conclusion is based on the production of diapausing eggs
when the leafhoppers were kept under short days (ten hours) during
the nymphal stage and the adult pre-oviposition period. Continuous
development of...
Tests were carried on in growth chambers and in the field to
determine if the harvest of daylength-sensitive long-day cereals
grown during the winter in Arizona could be hastened 30 days by the
use of night interruption.
Two durum lines which were near-isogenic for sensitivity to
daylength were used throughout...
Fourteen multiparous Holstein cows were paired by stage of
lactation and previous years milk yield and 14 Holstein first-calf
heifers were paired by stage of lactation. One member of each pair
was assigned to a 24L:OD or a 18L:6D photoperiod for 16 wk during
winter 1981 (Experiment 1). A similar...
Three Oregon snap beans were tested for photoperiodic
response on the basis of their overall flowering
patterns. Oregon 1604 and Oregon 4848 showed the same
cumulative flowering curves and percent pod set under
both 11 hour SD and 16 hour LD photoperiods. Under SD,
Oregon 2065 produced a similar flowering...
The photoperiodic responses of Douglas-fir (Pseudotsuga menziesii (Mirb,) Franco) seedlings grown from seed collected at Salmon Arm, British Columbia, Coconino National Forest, Arizona, and Southern Vancouver Island were studied. Plants were grown for 100 days under a 12-hour photoperiod at 200 C. The effective length of the daily light and...
I. The Effect of Artificial Photoperiod on Eating Behavior and Other
Behavioral Observations of Dairy Cows.
Twenty-eight cows were randomly assigned to a dairy photoperiod of
18 h light and 6 h darkness or to continuous light and observed 1 d each
month from December 1981 to February 19.82. Lighting...
Patterns of nest attendance behavior by breeding birds represent a parent-offspring trade-off in which adults balance self-maintenance with parental care decisions.
Incubation, in particular, is of interest because adults must provide an environment
suitable for embryonic development through nest-building and contact-incubation.
We evaluated how adult incubation constancy and nest visitation...
Bud break is a key adaptive trait that can help us understand how plants respond to a changing climate from the molecular to landscape scale. Despite this, acquisition of bud break data is currently constrained by cost, scale, and a lack of information at the plant scale on the environmental...
