• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.1
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• pp.29-37
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• 2002

This study was conducted to compare ozone sensitivity among Betula sp. by measuring visible foliar injuries and growth responses. Four Betula sp.(B. costata, B. davurica, B. platyphylla var.japonica and B. ermani) grown in the greenhouse, were transplanted in the plastic pots. One-year-old seedlings of four Betula sp. exposed to relatively high ozone concentration(100 ppb) for 8 h day$^{-1}$ for 5 weeks in fumigation chamber. We measured visible injuries, leaf numbers and leaf areas at the end of experiments, and growth effects were evaluated by measuring the relative growth rate(RGR) of height and diameter and the dry weights of leaf, stem and root once a week. Four Betula species showed the significant differences for growth responses by the ozone treatment. Growths of three species, except for B. ermani, were significantly reduced by the $O_3$ exposure. B. costata with leaf senescence at the early growing stage and B. davurica indicated highest visible foliar injury rate may be the sensitive species at the 100 ppb ozone concentration. Although the growth rate of B. ermani was reduced by 100 ppb ozone exposure at the early growing stage, B. ermani may be a tolerance species that recover the growth rate with the adaptation for the high ozone concentration.

• Korean journal of applied entomology
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• v.54 no.1
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• pp.1-6
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• 2015

This study was conducted to estimate the economic injury level (EIL) to leaf broccoli (leaf vegetable) by the diamondback moth (Plutella xylostella L.) in 2007 and obtain basic data for pest management. To investigate the relationship between initial density of diamondback moth larvae and broccoli leaf yield, experimental plots with five treatments (0, 0.5, 1.0, 1.5 and 2.0 larvae per plant) as initial density were established. We inoculated larvae on cheesecloth covering to survey changes in larval density. When grown for consumption, leaves of broccoli are harvested in periods. High levels of larvae were associated with significant reductions in leaf yield. There were 0%, 15%, 35%, 42%, 44% yield reductions due to a density of 0, 0.5, 1.0, 1.5, 2.0 diamond back moth larvae per plant, respectively, 25 days after larva inoculation. The regression equation used to predict leaf yield based on the number of initial larvae per plant was y = 1636-394x($R^2=0.79^{***}$>). EIL of the diamondback moth on leaf broccoli was 2~3 larvae per 10 plants for a damage level of 5%. The economic threshold was 1~2 larvae per 10 plants. Thus, diamondback moth management should be initiated when 1~2 larvae appear on 10 plants.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.7-12
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• 1992

This study was conducted to determine the effectiveness of silver thiosulfate(STS) in reducing $O_3$ injury to tomato plants(Lycopersicon esculentm Mill. 'Pink Glory'). Two days prior to $O_3$ fumigation, plants were given a foliar spray of STS solution at concentrations of 0, 0.2, 0.4, 0.6 mM contained with 0.05% Tween-20. STS concentrations below 0.6 mM were significantly effective in providing protection aginst $O_3$ exposure(16 h at 0.3 ppm). STS reduced leaf injury rate, defoliation of cotyledons, ethylene production and degree of epinasty induced by $O_3$ injury. STS slightly increased ethylene production in non-$O_3$-fumigated plants, but changes of chlorophyll content and transpiration rate on a whole plant basis were not observed. In $O_3$-fumigated plants, STS treatment reduced chlorophyll destruction but did not affect transpiration rate. STS treatment seemed not to affect peroxidase(POD) and superoxide dismutase (SOD) activity in non-fumigated plants but reduced increasing activity of POD by $O_3$ fumigation. However, such an effect as above was not found in SOD activity. Even though enzymatic protection effects were not confirmed, the fact that reduction of acute injury rate was attained for 16 h fumigation indicates that the phytoprotective effects of STS are not necessarily related to blocking the action of strees-induced-ethylene as an anti-ethylene agent.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.321-328
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• 1987

In order to examine the factors affecting herbicidal injury of pepper, crop injury and growth response of 2 red pepper cultivars and 2 sweet pepper cultivars to napropamide and pendimethalin were evaluated under defferent conditions of soil texture, organic matter, soil temperature and seeding depth in the greenhouse. Growth response of 4 pepper cultivars was also examined by roos dipping to napropamide and pendimethalin. More inhibition of top leaf growth by root dipping to napropamide was occurred in red pepper cultivars than in sweet pepper cultivars. However, sweet pepper cultivars showed more severe inhibition of top leaf growth by root dipping to pendimethalin compared to red pepper cultivars. Crop injury due to napropamide and pendimethalin was more severe in sandy soil than in loam soil and this trend was more remarkably shown in sweet pepper cultivars. Crop injury due to napropamide and pendimethalin was reduced with the increase in organic matter especially in cv. Walgeykwan and cv. Orient al Pimento. As seeding depth of pepper cultivars became deeper, crop injury due to napropamide and pendimethalin was reduced in cv. Walgyekwan and cv. Oriental Pimento.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.31-35
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• 2007

In order to find out the cause of plant injury, the symptom of plant injury, and contents of element concerned in the plant were analysed. Also, a case study was conducted to find out the factor of plant injury at a agriculture and industry complex in Gyeongsang province in 2004. The distribution of isomeric curve was made with meteorological data, toxic gas concentration exhausted from pollution source. The general symptom of plant injury by ammonia gas was dry and dead of leaves with white color. At low concentration of ammonia gas, plant leaf showed spots of reddish brown. The characteristic of plant injury symptom by hydrogen fluoride gas was that the symptom was appeared at the edge of leaf. The isomeric curve of sulfur dioxide at the region, where the plant was damaged, showed that the area was affected by exhausted gas from the pollution source. Especially, this area was affected more deeply at summer than any other season.

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

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.1
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• pp.78-80
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• 1993

Of the forma of Hibiscus Syriacus, national flower, a dozens of them have been recommended for landscape treess. To find out the highly resistant forma, 13 forma of Shrub al thea were fumigatedqr with $SO_2$ in phytotron and their visible injury was observed. Visible injury of Shrub al thea forma was spread on the vein in the shape of spot and diffused to whole leaf with wilting. The injury colors of forma were generally dull bluish green, dark grayish green. The tolerant forma to $SO_2$ were Sanchunyeo, Saeachim, Sulag and the highly sensitive forma were Lusi, Youngkwang. Therefore, Sanchunyeo, Saeachim and Sulag were recommeneded to plant in polluted areas.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.975-977
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• 2010

Ammonium nitrogen is volatilized as ammonia at high pH soil. This study was conducted to observe an injury cause of egg plant grown in a high pH rockwool amended with ammonium phosphate. The etiolation symptom (yellowing) was appeared on veins of a leaf but not in healthy root when nutrient solution containing ammonium phosphate in addition to essential elements was applied in a top soil of which pH was 7.8. However, the same symptom did not appeared in the egg plant from the top soil in which the nutrition solution containing potassium phosphate instead of ammonium phosphate was applied. pHs were similar between these two different solutions. This revealed that the injury was caused by ammonia gas.

• Proceedings of the Korean Society of Crop Science Conference
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• 2007.11a
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• pp.200.2-200.2
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• 2007

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.209-217
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• 1989

Seedlings of 6 tree species were treated with artificial acid rain and acid mist (pH 5.0, 4.0, 3.0) and ground water (pH 6.5), to select $SO_2$-resistant tree species. The growth variable, leaf injury rate and chlorophyll content were measured and compared among the various pH levels. Seedling height of Rosy multiflora decreased with deceasing pH levels of artificial acid rain and was tallest at control plot, but that of Ailanthus altissima was tallest at pH 5.0 plot. For the seedlings of Robinia pseudoacacia, Magnolia obovata and Wistaria floribunda, top and root dry weights per seedling at pH 5.0 plot were higher than those at control plot. Leaf injury rate(injured leaf area and injured leaf rate) increased with decreasing pH levels of artificial acid rain, the changes of leaf chlorophyll content was slightly different among tree species. Leaf chlorophyll content of Rosa multiflora, measured during the period July to September, decreased with decreasing pH levels of artificial acid rain. Leaf chlorophyll content of Magnolia obovata increased on July, but decreased severely on September, with decreasing pH levels, of artificial acid rain.