نتایج جستجو برای: cold hardiness
تعداد نتایج: 107687 فیلتر نتایج به سال:
To elucidate the relationship between diapause and cold hardiness in the oriental corn borer, Ostrinia furnacalis, the levels of various substances, cold hardiness and respiration were measured in diapausing and post-diapausing overwintering larvae. Under field conditions, diapause terminated between November and January, although O(2) consumption, measured at 20 degrees C in the laboratory, re...
use of available moisture and by avoiding heat stress. Fall planting is desirable because drier soil conditions Available winter hardy lentil (Lens culinaris Medik.) germplasm allow for planting the crop without the excessive soil has prompted interest in the development and use of cultivars that compaction that is common with spring planting in cold can be fall planted in cold highland areas. ...
1. BULA, R. J. & D. SMITH. 1954. Cold resistanice & chemical composition in overwintering alfalfa, red clover, & sweet clover. Agron. J. 46: 397-401. 2. BULA, R. J., D. SMITH, & H. J. HODGSON. 1956. Cold resistance in alfalfa at two diverse latitudes. Agron. J. 48: 153-156. 3. JANSSEN, G. 1929. The relationship of organic root reserves & other factors to the permanency of alfalfa stands. J. Am....
Although many studies of ectothermic vertebrates have documented compensatory changes in cold hardiness associated with changes of season, much less attention has been paid to adjustment of physiological functions and survival limits following more acute exposure to cold. We investigated the ability of hatchling painted turtles (Chrysemys picta) to increase cold hardiness in response to brief e...
Seasonal variation in photochemical activity and hardiness in clones of Norway spruce (Picea abies).
We investigated changes in photochemical activity and cold hardiness of detached needles of three clones of Picea abies (L.) Karst. by measuring variable chlorophyll fluorescence (F(v)/F(m)), before and after artificial freezing, from September to June. Photochemical activity varied considerably during the study, but only minor differences in photochemical activity among the clones were observe...
Eggs of temperate Aedes albopictus populations are cold hardy and can diapause, but tropical populations are not cold hardy and cannot diapause. Heterozygotes possess intermediate diapause and cold hardiness. Males of a tropical strain from Malaysia with a distinctive genetic marker were released into an existing temperate population in East St. Louis, Illinois. Subsequent egg samples from the ...
The hemlock woolly adelgid (HWA), Adelges tsugae Annand, primarily infests trees along the eastern seaboard in USDA plant hardiness zones where the minimum low temperature does not exceed –28.8°C. Laboratory studies were done to determine the low lethal temperature of HWA collected in January, February, and March from locations within different USDA plant hardiness zones. The Mt. Tom, Massachus...
The abilities of cold-hardy plants to resist deacclimation during transient warm spells and to reacclimate when cold temperatures return are significant for winter survival. Yet compared to the volume of research on the biology of cold acclimation, relatively little is known about how plants maintain and/or reacquire cold hardiness in late winter and spring. This review summarizes the past 40 y...
Predicting insect responses to global climate change involves understanding cross-generation effects of temperature. The majority of temperate insects overwinter in a state of diapause, a pre-emptive response to winter conditions associated with increased cold hardiness. Diapause is often induced following maternal adult detection of an environmental cue signifying the onset of winter, whilst d...
stresses caused by their freezing and thawing. A key difference between a hardy plant and a non-hardy plant is believed to be where the ice forms in freezing: inside the living cells or outside of them. If ice forms inside of cells, it is almost always fatal to them, and this is probably the principal cause of frost kill in non-hardy plants. Normally hardy tissue may be killed by moderate tempe...
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