• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.3
• /
• pp.151-161
• /
• 2016

This study was conducted to find out influence of dormancy level and carbon concentration on freezing hardiness in bourse shoot of 'Fuji' apple tree. Bourse shoot of 'Fuji' adult apple tree grafted on M.26 and M.9 rootstocks were used as experimental materials. Dormancy levels of bourse shoot were categorized according to the periods as follows the internal dormancy (late January), the early days after internal dormancy breaking (early February), the late days after internal dormancy breaking (late February), the bud break (late March), and the full bloom (late April). Chilling temperatures with bourse shoot were ranged from 0 to $-40^{\circ}C$. Also, the freezing hardiness according to carbon concentrations were investigated on 'Fuji'/M.9 apple tree that defoliated severely by Marssonina blotch (defoliation) and that of below the average 20 cm in shoot length through heavy crop load (weakness). Results showed that freezing hardiness of bourse shoot may become weaker after internal dormancy breaking. There was no differences in the carbon concentration of bourse shoot of 'Fuji' apple tree grafted on M.9 and M.26, so may be resulted in no difference in freezing hardiness both of bourse shoot grafted on M.9 and M.26 rootstock. Carbon concentration in bourse shoots with weakness and C/N ratio in bourse shoots with defoliation were lower than that of healthy. It may be shown that the freezing hardiness of defoliation and weakness were weaker than that of healthy.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.s02
• /
• pp.96-114
• /
• 1989

There are several meterorolgical stresses in the winter cereal crops. Among these stresses, cold injury is one of the most important stresses for wheat and barley production in Korea. The reduction in grain yield of the wheat and barley due to cold injury has occurred almost every year in Korea. The objective of the study was to get the basic information in relation to the cold injury and to detect the method minimizing the damage of cold injury. When the air temperature was the ranges of -13$^{\circ}C$ to -15$^{\circ}C$, the soil temperature at the crown part of the plant was very stable, whereas in the ranges of -2$^{\circ}C$ to -3$^{\circ}C$ the soil surface temperature was more unstable and cold than air and subterranean temperatures. The different parts of the plant in wheat and barley possess the different levels of cold hardiness. In comparison to the cold hardiness of plant parts, the leaf and crown are the less sensitive to cold injury than root and vascular transitional zone. The type and extent of stress is determined by the redistribution pattern of water during freezing. These types from freezing processes were three types: a) Equilibrium freezing pattern b) Non -equilibrium freezing pattern, c) Non-equilibrium freezing pattern typical of tender tissues. Cold hardiness in wheat plants were more harder than barley plants at vegitative stage, but inverted at the reproductive stage. Injuries by low temperature during the seasons of barley cultivation in Korea were occured mainly in four stage; in the first and third stage, frost injury occurs, the second stage, freezing injury, and the fourth stage, chilling injury.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.14
• /
• pp.97-109
• /
• 1973

1. The relatively lower prehardening temperature was more effective on increase of the hardiness of the intermediately hardy varieties than the higher one but either the extremely hardy or nonhardy varieties did not respond to the temperature as much as the intermediate types. 2. Five degree Centigrade was generally more favorable than $2^{\circ}C$ on hardening of the plants, especially when frozen at higher temperature for shorter duration. 3. It appears that photoperiod during prehardening and hardening did not play so important role as temperature on the hardiness. 4. The higher the soil moisture content, the higher the frost injury occurred. 5. Application of nitrogen increased markedly the hardiness and % DM of the plants. Percentage of dry matter of young seedlings might be used as an easy and rough criterion for evaluating hardiness since there was a highly significant regression of varietal frost injury on the %DM. 6. Four days appeared to be enough for hardening of plants although the plants increased gradually the hardiness as duration of hardening extended. Dehardening of the plants at relativity higher temperature took place rapidly within one to four days. 7. Under this controlled environment, freezing at about $-8^{\circ}C$ for 24 hours seemed the best for the purpose of evaluating the hardiness to low temperature. 8. It is believed that assessment of frost injury should be done at least one week after freezing. Some varieties showed strong ability to recover from the damage as recovery period was extended. 9. As a whole, Cd 80 and 83 were the most hardy and followed by Cappelle and Maris Otter. Four. winter oats varieties and Jufy I belonged to the intermediate type while the other three spring varieties were nonhardy at all. Peniarth was comparable with Maris Otter in hardiness. S 147 appeared the least hardy among the winter oats varieties. 10. It is evident that water-soluble carbohydrate content is associated with the hardiness to some extent but not primary factor involved in hardiness.

• Journal of Korean Society of Forest Science
• /
• v.27 no.1
• /
• pp.1-4
• /
• 1975

Freezing resistance of apple (Malus pumila) cultivars was measured to find out the most cold hardy apple variety among the five cultivars which are promissing in Korea. The measurement of freezing resistance for two varieties of dwarf interstock, was also included to compare the cold hardiness among scions and interstocks. The freezing resistance was in order from lowest to highest; winter bud, cambium, xylem ray parenchyma and bark cortex in all cultivars except EM26. The difference in cold hardiness among cultivars and interstocks was not consistent among tissue parts of twig except in cultivar Nugget-spur of which all tissue parts showed least cold hardiness. The difference among tissue parts with in a cultivar was discussed in terms of choosing the most cold hardy, and the most resistant cultivars to late frost damage.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1994.10a
• /
• pp.3-4
• /
• 1994

• Journal of Korean Society of Forest Science
• /
• v.26 no.1
• /
• pp.19-22
• /
• 1975

Freezing resistance of ten cultivars of Chestnut (Castanea crenata S. et Z.) collected from four different sites of Kyunggi Province, Korea on March 2, 1975, was measured to find out the differences among tissue parts, and those among cultivars. The freezing and thawing rates were controlled lower than $6^{\circ}C/hr$. which occurs in nature. The resistance to low temperature was in order from lowest to highest; winter bud, cambium, xylum ray parenchyma and bark cortex. The difference in cold hardiness among cultivars was not consistent among tissue parts of twig stem except in cultivar Dan-Taeck of which all tissue parts showed highest cold-hardiness. The importance of the study on the seasonal variation in cold hardiness of different tissue parts was discussed in terms of choosing the most cold resistant Chestnut culitivar in Korea.

• Journal of Korean Society of Forest Science
• /
• v.48 no.1
• /
• pp.25-28
• /
• 1980

This study examined the cold hardiness of eight cultivars of common persimmon and six cultivars of sweet persimmon growing at the southern part of Korea, to know the most susceptible tissue part, timing of damage, and the difference in freezing resistance between the cultivars during the winter of '77-'78. The cold hardiness of winter bud, cambium and xylem parenchyma of the current year twig was measured on three collection dates; 10 / 26 / 77, 1 / 26 / 78 and 3 / 26 / 78. The results were obtained as follows, 1. The least cold hardy tissue part was winter bud during mid winter and early spring. 2. On the basis of the cold hardiness of the winter bud sweet persimmon cultivars appeared to be less cold hardy than common persimmon cultivars. In the cold hardiness of cambium and xylem parenchyma, there was no consistance differece between the two group of cultivars. 3. The late frost during early spring appeared to cause the most critical damage to the winter bud of persimmon.

• Journal of Bio-Environment Control
• /
• v.16 no.3
• /
• pp.269-273
• /
• 2007

Freezing hardiness of winter bud and branch according to dormancy level and low temperature, in persimmon (Diospyros kaki) cultivars, was investigated by electrolyte leaching rate, triphenyltetrazolium chloride (TTC) test, and sprouting. Electrolyte leaching rate was lowest in branch of 20th January and was highest in the 20th March. The electrolyte leaching rate of 'Fuyu' and 'Cheongdobansi' was high in the 20th January and was low in the 20th February, but 'Uenishiwase' and 'Nishimurawase' was opposed to that. 'Hachiva' was the middle level in the cultivars. Absence rate by TTC test was highest in the 20th January and was low in the others. The 20th March had a great decrease in $-10^{\circ}C$ treatment. The absence rate of 'Fuyu' and 'Uenishiwase' was low in the 20th January and March and was high in the 20th February. 'Nishimurawase' and 'Hachiya' had a high level irrespective of dormancy level. Sprouting was highest in the 20th February and was lowest in 20th March. Most cultivars were not sprout in $-20^{\circ}C$ treatment and 'Fuyu', 'Nishimurawase' and 'Cheongdobansi' was a little high level irrespective of dormancy level. 'Hachiya' was only high in the 20th January. Thus, freezing hardiness of persimmon was very weak low temperature after dormancy breaking and was not different between astringent and non-astringent persimmon.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.16 no.1
• /
• pp.51-58
• /
• 2014

Freezing hardiness of winter bud and branch of several pear (Pyrus pyrifolia) cultivars according to degree and duration of low temperatures was investigated by sprouting, electrolyte leaching rate and triphenyltetrazolium chloride (TTC). Sprouting rate as infected by degree and duration of low temperature were different between cultivars. The lower temperature, the longer duration, sprouting rate was decreased. Electrolyte leaching rate was showed above 30% at below $-30^{\circ}C$ treatment regardless of cultivars and duration. The lower temperature and the longer duration, Electrolyte leaching rate was increased. Electrolyte leaching rates of Manpungbae, Niitaka and Chuwhangbae at $-30^{\circ}C$ for 9 hours treatment which were observed high sprouting rate, were lower than those of other varieties. Absorbance rates by TTC test at $-21^{\circ}C$ treatment were 66.0 to 96.5% for 6 hours, 49.4 to 91.9% for 9 hours, and 37.3 to 89.4% for 12 hours. Freezing hardiness of pear cultivars at ecodormancy was different according to degree and duration of low temperature treatments.

• Journal of Korean Society of Forest Science
• /
• v.28 no.1
• /
• pp.31-35
• /
• 1975

The present study explored the rapid effect of low temperature on the freezing resistance of dehardening twigs of three apple cultivars and sweet cherry. The effect of low temperature was depending upon the thawing treatment following to the low temperature treatment. When the freezing temperature to $-9^{\circ}C$ for three hours followed by thawing treatment ($5^{\circ}C$) was given repeatedly twice, the low temperature increased apparently the cold hardiness of apple and cherry by 3 to $9^{\circ}C$. On the other hand, when the freezing temperature ($-9^{\circ}C$) for ten hours was pretreated without thawing, the low temperature appeared not affecting the cold resistance of the twigs. The role of freezing-thawing temperature cycle in nature was discussed as a signal of environmental stimulus to which dehardening plant may be responding to increase their cold hardiness so as to adapt against the damage of late frost in early spring.