• Weed & Turfgrass Science
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• 제5권4호
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• pp.268-273
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• 2016

Potassium is well-known to improve turfgrass tolerance to environmental stresses such as low temperature and drought stress. Low mowing height reduces leaf area of turfgrass that is main place for photosynthesis and carbohydrate production. Closely-mowed turf would suffer from summer decline by low level of carbohydrate resulted from low photosynthesis of reduced leaf area. The objective of the study is to investigate K rate and mowing height for Kentucky bluegrass. The K rate treatments were 5, 10, and $20g\;K_2O\;m^{-2}$ for the low, medium and high K rates, respectively. The bi-weekly mowing treatment was made for treatments. Mowing was implemented at 40 and 100 mm using a rotary mower. Regardless K rates, the high mowing height would be required when the air temperature is higher than $28.5^{\circ}C$ and high turfgrass quality of Kentucky bluegrass is needed. When the air temperature is optimal for cool-season grass, the high mowing height and the low K rate is needed for the root length of Kentucky bluegrass.

• 식물병연구
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• 제29권4호
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• pp.425-432
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• 2023

키위산업은 키위나무가 급속하게 시들면서 1-2년 사이에 말라죽는 키위 쇠락증상의 출현으로 위협을 받고 있다. 쇠락증상의 주요 증상은 뿌리 피층 붕괴, 잎 괴사, 낙엽, 열매 표피 주름 및 잔가지 시들음이다. 키위 쇠락증상은 장마 후 한여름에 골드키위(Actinidia chinensis var. chinensis)와 그린키위(A. chinensis var. deliciosa)에서 모두 발생하였다. 키위 쇠락증상은 침수나 통기 불량으로 인해 수분이 많은 점질토양에서 심하게 발생하는 것으로 나타났다. 이 증상과 직접적인 관련이 있는 병원균은 없었다. 키위 쇠락증상은 침수와 같은 수분 스트레스에 강한 바운티대목(Bounty 71)을 사용하여 효율적으로 예방할 수 있을 것으로 전망된다.

• 한국환경복원기술학회지
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• 제14권2호
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• pp.1-10
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• 2011

Six pine trees (Pinus densiflora S. et Z.) at the Euilimji Lake Park in Jecheon were collected to investigate tree ages, growth decline pattern and the years of death. Tree-ring measurement was carried out using the Lintab with a resolution of 0.01mm. Tree age were 80-176 years. Cross-dating between the tree-ring series of each tree and the local chronology from Worak Mountain resulted that four and two trees died in 1998 and 1999, respectively. Three dead trees had only formed earlywood in the outermost tree ring and the others had incomplete latewood. Therefore, it was proven that the former trees died between spring and early summer, whereas the later ones died during late summer and/or autumn. The simultaneous deaths of trees suggest the insect damage and/or drought may be the crucial reason of the death, but frequent reaction woods, which were formed by leaning stem, and scars formed by physical damage may also contribute to the death.

• Asian-Australasian Journal of Animal Sciences
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• 제3권4호
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• pp.331-336
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• 1990

In order to evaluate the adaptability of Aardi goats to arid environment, 5 Aardi bucks were deprived of water for four days during spring and summer seasons. The rise in average maximum ambient temperature from $24.8^{\circ}C$ in spring to $35.8^{\circ}C$ in summer caused a significant rise in rectal temperature ($0.3^{\circ}C$), respiratory rate (62%), serum osmolaity (8%) and serum sodium concentration (17%). While, it resulted in a significant decline in dry matter intake (50%), urine volume (74%) and fecal water excretion (60%) compared with their values in spring, but had no significant effect on the volume of drinking water. At the end of the 4-days deprivation period during spring, respiratory rate, dry matter intake and urine volume were reduced by 18, 77 and 91% relative to their average in control goats. The corresponding reduction in summer were 58, 100 and 100%. Serum osmolaity was risen by 15% in spring deprived goats and 29% in summer deprived goats. Rectal temperature rose by a mean value of $1.3^{\circ}C$ only in goats deprived of water in summer. Percent of moisture in the feces declined from 64 in control goats, to 24% in water deprived goats during spring season. The corresponding values in summer were 25 and 6%. These responses of Aardi goats deprived of water in summer indicate that they possess a water economy mechanism enable them to tolerate infrequent drinking in hot-arid environment.

• Asian-Australasian Journal of Animal Sciences
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• 제19권8호
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• pp.1134-1138
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• 2006

Forest tree leaves (12 different species) of semi hilly arid region of Punjab State were collected at 30-day interval throughout the year to assess the seasonal variations in tannin profile. Tannins were extracted and fractionated from fat free samples and data were analyzed statistically by $12{\times}12$ factorial design. The leaves of Anogeissus latifolia had the highest (p<0.05) concentration of total phenols (17.4%), net (15.9%) and hydrolysable (16.9%) tannins, followed by leaves of Acacia nilotica. Majority of the tree leaves selected had moderate levels (2-5%) of net tannins. Leaves of Carrisa had the highest (p<0.05) concentration of condensed tannins (CT), whereas the leaves of Anogeissus had the lowest (p<0.05) concentration of condensed tannins. The protein precipitable phenols (PPP) corresponded well with the net tannin content present in different tree leaves. Seasonal variation data revealed that in summer, net tannins and PPP decline in leaves of Bauhinia and Zizyphus whereas the net tannin content of Anogeissus and that of Carrisa increased during summer. The CT and PPP content in the leaves of Pheonix, Leucaena, Zizyphus and Ougenia increased in winter till spring season. Tree leaves generally had higher concentration of HT during summer months. It was concluded that leaves of leaves of A. nilotica, A. latifolia and L. leucocephala could serve as an excellent alternate feed stuffs for ruminants. However, leaves of Phoenix, Carrisa, Bauhinia and Dodonea should be avoided.

• Journal of Ecology and Environment
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• 제47권4호
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• pp.241-249
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• 2023

Background: This study analyzed the drought responses of five forest tree species grown in Korean peninsula, Korean fir Abies koreana (Ak), eastern white pine Pinus strobus (Ps), keyaki Zelkova serrata (Zs), tulip tree Liriodendron tulipifera (Lt), and Japanese elm Ulmus japonica (Uj). Physiological (chlorophyll, root collar diameter [RCD]) and biochemical responses (non-structural carbohydrates, proline, lipid peroxidase and abscisic acid [ABA]) of the plants grown under mild (MD) and severe drought (SD) were compared. Results: In this study, three soil moisture regimes: control (100% precipitation), MD (60% reduction in precipitation) and SD (20% reduction in precipitation) were applied. Soil moisture content showed high water content in control site compared to MD and SD. A decline in RCD was found for Korean fir, keyaki, and tulip plants, with eastern white pine and Japanese elm showing no significant decline to the prolonged drought exposure (both MD and SD). Total chlorophyll showed a significant decline in Korean fir and tulip, with the sugar levels indicating a significant increase in Korean fir and keyaki species under SD compared to control plants. Non-significant decline in sugar level was noted for eastern white pine and Japanese elm. High accumulation of ABA, malondealdehyde and proline was noted in Korean fir, tulip, and keyaki under SD compared to control. Signs of tree mortality was only observed in Korean fir under MD (38%) and SD (43%). Conclusions: The observed findings indicate the drought responses of five tree species. The majority of the morpho-physiological (especially mortality) and biochemical variables assessed in our study indicate superior long-term drought resistance of Ps and Uj compared to the highly sensitive Ak, and moderately sensitive Lt and Zs. The results provided will help species selection for afforestation programs and establishment of sustainable forests, especially of drought-tolerant species, under increased frequency and intensity of spring and summer droughts.

• The Korean Journal of Ecology
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• 제16권4호
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• pp.397-408
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• 1993

대기의 오존농도에 대한 민감도가 다른 스트로브 잣나무의 가스교환과 아스코르브산, 글루타치온의 농도변화를 1988년 6월부터 시작하여 10개월간 측정하였다. 오존에 의해 가시적 피래를 입은 나무의 당년잎의 건중량과 길이는 저항성이 있는 나무에 의해 각각 60~75%와 45~60% 작았다. 순광합성량과 잎의 전도율은 전체적으로 가스교환이 감소하기 시작하는 늦은 9월까지 저항성이 있는 나무에서 높은 값을 보였다. 증산작용도 비슷한 양상을 보였다. 당년잎의 아스코르브산과 글루타치온 농도는 여름, 가을 동안 계속 증가하여 겨울에 최고치를 나타내다가 봄에 감소하기 시작했다. 아스코르브산 농도는 4월에 감소하기 시작할 때 까지 일년 내내 저항성이 있는 나무에서 높은 농도를 나타내었다. 예민한 나무와 저항성이 있는 나무사이의 아스코르브산 농도차이는 겨울동안보다 (8~19%) 여름에 (25~30%)) 훨씬 컸다. 글루타치온의 농도는 에민한 나무와 저항성이 있는 나무에서 비슷한 결과를 보였다.

• 원예과학기술지
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• 제32권5호
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• pp.614-622
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• 2014

Melons (Cucumis melo L.) are generally grafted onto Cucurbita rootstocks to manage soilborne pathogens such as Monosporascus root rot and v ine decline (MRR/VD) and Fusarium wilt. However, g rafting onto Cucurbita rootstocks reportedly results in the reduction of fruit quality. In this study, the resistance to MRR/VD, yield, and fruit quality of melons grafted onto melon rootstocks were evaluated under greenhouse conditions. Eight melon rootstocks (R1 to R8) were used and the inodorus melon 'Homerunstar' was used as scion. Melon rootstocks R1 to R6 were selected based on resistance to MRR/VD under greenhouse conditions. Non-grafted 'Homerunstar' and plants grafted onto squash interspecific hybrid 'Shintozwa' rootstock (Cucurbita maxima D. ${\times}$ C. moschata D.) served as controls. Grafted melons were cultivated in the greenhouse infested with Monosporascus cannonballus during two growing seasons (summer and autumn). The responses to MRR/VD, yield, and fruit quality differed depending on the rootstocks and growing season. The melons grafted onto 'Shintozwa' exhibited less severe disease symptoms and higher survival rates than non-grafted melons in both seasons. While the melon rootstocks in the summer cultivation did not increase the survival rate compared to non-grafted melons, the melon rootstocks R1 and R2 in the autumn cultivation led to higher survival rates. The melon rootstocks resistant to MRR/VD increased the percentage of marketable fruits and marketable yields. Grafting onto the melon rootstocks caused little or no reduction of fruit quality such as low calcium content, fruit softening, and vitrescence, especially in lower-temperature autumn season. Accordingly, these results suggest that grafting onto the melon rootstocks may increase the tolerance to MRR/VD and the marketable yield without a reduction of fruit quality.

• 아시안잔디학회지
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• 제21권2호
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• pp.127-135
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• 2007

Korea and Japan hosted the FIFA World Cup Soccer Game in 2002. Ten stadiums had been built and more than 30 soccer grounds for practice were renovated in Korea. Sport fields in both countries had problems on cool-season turfgrass growth and quality by summer decline during humid and warm climate especially followed by intensive uses. We measured the effects of air-flow system, which is designed to optimize rootzone soil gas and moisture levels to promote the growth and maintenance turfgrass. This experiment was carried out to verify the effects of the system on soil gas exchange, ground resilience, and turfgrass recovery in turfgrass rootzone. Within 1 or 2hr of operation of the system, rootzone soil gas ($CO_2$, $O_2$) levels returned to natural atmospheric levels completely Soil $CO_2$ levels began to decrease within the first 10 min of operation of the system. The levels were reduced from 1.3 to 0.06% after 30 min, and natural atmospheric levels within 1 hr. When the system was turned off, $CO_2$ levels increased to 0.36% and 0.7% after 5 and 20 hr, respectively. The application of the system did not affect the resilience of turf surface after traffic treatments. Higher traffic treatment resulted in higher surface resilience especially in zoysiagrass plots. Operation of the system had a significant beneficial impact on turf recovery by increased root dry wight and improved turf quality, as compared with the non-operated check plots.

• Animal Bioscience
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• 제35권1호
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• pp.96-104
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• 2022

Objective: Sarcoplasmic proteins include proteins that play critical roles in biological processes of living organisms. How seasons influence biological processes and meat quality of postmortem muscles through the regulation of protein phosphorylation remain to be investigated. In this study, the phosphorylation of sarcoplasmic proteins in pork longissimus muscle was investigated in four seasons. Methods: Sarcoplasmic proteins were extracted from 40 pork carcasses (10 for each season) and analyzed through ProQ Diamond staining for phosphorylation labeling and Sypro Ruby staining for total protein labeling. The pH of muscle, contents of glycogen and ATP were measured at 45 min, 3 h, and 9 h postmortem and the water (P_2b, P₂₁, and P₂₂) was measured at 3 h and 9 h. Results: A total of 21 bands were detected. Band 8 (heat shock cognate 71 kDa protein; heat shock 70 kDa protein 1B) had higher phosphorylation level in summer than that in other seasons at 45 min postmortem. The phosphorylation levels of 3 Bands were significantly different between fast and normal pH decline groups (p<0.05). The phosphorylation levels of 4 bands showed negative associations with immobilized water (P₂₁) and positive association with free water (P₂₂). Conclusion: The phosphorylation levels of sarcoplasmic proteins involved in energy metabolism and heat stress response at early postmortem time differed depending on the seasons. These proteins include heat shock protein 70, pyruvate kinase, phosphoglucomutase-1, glucose-6-phosphate isomerase, and carbonic anhydrase 3. High temperatures in summer might result in the phosphorylation of those proteins, leading to pH decline and low water holding capacity.