• Journal of Ecology and Environment
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• v.31 no.3
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• pp.193-200
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• 2008

We obtained quantitative information on leaf unfolding and leaf shedding by observing 45 species of cool temperate deciduous trees in an arboretum over 5 growing seasons. These trees were in leaf (the foliage period) for 207 days on average after 1 April; 50% of leaves had been shed by 192 days after 1 April. Duration from the start of leaf unfolding to 50% leaf shedding was 157 days on average. Leaf unfolding began 35 days on average after 1 April. For leaf unfolding to begin, a$ 51^{\circ}C{\cdot}day$ of cumulated daily mean air temperature above $5^{\circ}C$ from 1 January (modified Kira's warmth index) was needed. Fifty-nine days elapsed between initiation and the final stage of leaf unfolding. The period of net photosynthetic assimilation was 157 days. The species with succeeding- type leaf unfolding associated with the anemochore seed type dominated the early stage of succession, while the species with flush-type leaf unfolding tended to dominate the late stage of succession. Few species were found in regions where late frosts occur after the day when the cumulative temperature for leaf unfolding is achieved. Biological characteristics include time of leaf unfolding, which affects the life history of each species, so that each species occupies its own niche in the stand. We conclude that that leaf phenology, such as timing of leaf unfolding and leaf shedding, is one of the components of each species' ecological characteristics.

• Journal of Forest and Environmental Science
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• v.34 no.6
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• pp.435-450
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• 2018

Phenological events of four Rhododendron tree species (viz. R. arboreum, R. arboreum ssp. delavayi var. delavayi, R. barbatum and R. kesangiae) was monitored in temperate mixed broad-leaved forests of Arunachal Pradesh, India. Phenological events like flower bud formation, flowering, fruit setting, fruit maturing, seed dispersal, leaf bud formation, leaf flushing, and leaf shedding were recorded. Indices i.e., phenophase sequence index (PSI), active phenophasic period of the species (APS) and index of reproductive/vegetative activity (RVA) were also calculated. Present study revealed that bark consistency, growth form and leaf pattern of the studied species have showed variations among the species. Rhododendron species exhibited the phenological events overlapping with other phenophases. The peak flower bud formation was observed during the winter; R. arboreum ssp. delavayi var. delavayi start flowering from December, while the flowering in rest three species exhibited during February to April. Fruit setting occurred during summer to autumn while fruit maturation revealed peak during November. Leaf bud formation illustrated two peaks in April and May, leaf flushing exhibited peak in June, while leaf shedding peaked during October to November. Active phenophasic period of the species were found 12 months, which revealed that species engage in various phenophase activities throughout the year. Phenophase sequence index ranged between 0.8 to 0.9 (PSI ${\geq}0.6$), signifies that species have a sequential arrangement of phenophases. Index of reproductive/vegetative activity of the species exemplified >1, indicate that the reproductive phenophases were dominance over vegetative phenophases. The study have provided substantial insight on the life cycle events of Rhododendron species and ecological approaches for further scientific study with recent climate change and effective management and conservation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.213-218
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• 2014

Effects of elevated $CO_2$ on leaf phenology of Quercus acutissima were examined using open-top chambers, which had ambient and elevated $CO_2$ concentrations (ambient ${\times}1.4$, ambient ${\times}1.8$). To analyze the effect of chamber, non-treatment block was established near outside of the chambers. In 2013, budburst, leaf unfolding, coloring, and shedding were surveyed, and spring phenology was surveyed in 2014. Thermal sum (base temperature $+5^{\circ}C$) of each phenological event occurred was recorded. In addition, bud samples were collected and analyzed for carbohydrate contents in March 2014. Elevated $CO_2$ concentration advanced budburst and leaf unfolding, and delayed shedding in 2013. However, in 2014, the temperature of the spring season was high, and there was no significant effect of elevated $CO_2$ concentration on spring phenology. Carbohydrates content, such as starch, total non-structural carbohydrate and total soluble sugar, were significantly increased in response to elevated $CO_2$ concentration. It has been proposed that elevated $CO_2$ concentration could extend the growing season of temperate species with increased possibility of frost damage due to early bud opening and leaf unfolding. However, our analysis showed that the increased carbohydrate concentration in bud under elevated $CO_2$ would reduce the possibility of early spring frost damage by acting as cryoprotectant.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.5
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• pp.515-522
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• 1995

The field experiment was carried out to study the growth and fodder yield of the Gliricidia sepium provenances in fence system in dryland farming area in Bali, Indonesia for 24 months. The design of the experiment was a completely randomized block arrangement, consisted of 16 treatments (Gliricidia sepium provenances) and 12 blocks with 10 plants per provenance. Of the 16 gliricidia provenances, six were from Mexico (M), four were from Guatemala (G), and one each was from Colombia (C), Indonesia (I), Nicaragna (N), Panama (P), Costa Rica (R) and Venezuela (V). After 40 weeks establishment the gliricidia were lopped regularly 4 times a year, twice during the four month wet season and twice during the eight month dry season at 150 cm height. There were variations (p < 0.05) in stem elongation from 10 to 121 cm, leaf retained from 48 to 105%, leaf shedding from 53 to 86%, branch number from 4 to 7, fodder yield from 281 to 648 g DW/plant, and wood yield from 53 to 179 g DW/plant; and such variations were affected by the seasons. Retalhuleu provenance of Guatemala (G14), Belen provenance of Nicaragua (N14) and Bukit Bali provenance of Indonesia (I) were ranked first, second and third, respectively, measured in terms of stem elongation, leaf retention, fodder and wood yields during the wet and dry seasons.

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.225-231
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• 2001

This study was conducted to examine effect of different environment conditions in glass, PC, PET and PE greenhouses controlled by different environment control systems on the growth of green pepper. Light transmittance of 64.7% in the glass greenhouse was the highest among different green-houses. Air temperature was the highest in the glass greenhouse when ventilators were closed, and was the highest in the PE greenhouse when ventilators were open. Air relative humidity was the highest in the PE greenhouse during 24 hours. The amount of solar energy accumulated in soil was the greatest in the glass greenhouse and this energy released during the night escaped through covering materials. Latent heat and solar energy affected air temperature increased in greenhouses. The air temperature of glass greenhouse was 27.5$^{\circ}C$ at 11 O clock, which was the highest air temperature among the all greenhouse types. Clear differences were observed in leaf area and plant height at 30 days after transplanting. Days to first flowering was the shortest in the glass greenhouse with 72.7 days. Flower shedding was the greatest in the PE greenhouse with 12.6%. Days to fruit harvesting was the shortest in the glass greenhouse with 14.3 days. Fruit quality, such as fruit length, fruit diameter, fruit flesh thickness, and vitamin C content, was the best in the glass greenhouse. Percent marketable fruits was the highest with 95.3% when the pepper was grown hydroponically in the glass greenhouse.

• Journal of Plant Biology
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• v.23 no.1
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• pp.17-25
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• 1980

Kidneybean(Phaseolus vlgaris L.) and buckwheat(Fagopyrum esculentum M$\"{O}$nch) seedlings cultured with Hoagland solution to the height of 7 to 10cm in the earthern pot containing sand were used for experimental plants. One group of the plants was irrigated with Hoagland solution composed of various Al concentrations of 0 to 1,000 ppm containing 50ppm Ca, and the other group was irrigated with Hoagland solution composed of various Ca concentrations of 0 to 1,000ppm containing 100ppm Al for a month during June and July. By Al-surplus over 100ppm, the margins of backwheat leaves were curied down and turned into yellow-brown necrosis simialr to Ca-deficiency, and the old kidney bean leaves showed marginal and veinal chlorosis in addition to the early shedding of leaves. With Al-surplus of 100ppm the content of chlorophyll a and b in both plants was decreased by 30~40%. The ratio 3/1 of chlorophyll a/b was not altered by Al-surplus and Ca-deficienty at an early stage, but it was affected markedly at a final stage of growth. Leaf respiration with 100ppm Al containing 50pm Ca was slightly affected in buckwheat, but decreased by 20% in kidneybean. With Al-surplus of 100ppm the ATP content was decreased by 32% in the kidneybean leaves and by 80% in buckwheat leaves, whereas with Ca-deficiency it was decreased by 72% in kidneybean and by 90% in buckwheat. The rhythm of ATP level showed self-relience without being affected by light or temperature under the green house condition although by Al-s rplus and Ca-deficiency the ATP level of the rhythm was lower than that of control.trol.

• Journal of Korean Society of Forest Science
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• v.76 no.4
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• pp.370-375
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• 1987

This study was conducted to examine the position effect of axillary buds on shoot multiplication and rooting with 1-year-old seedlings of Quercus acutissima. Shoot multiplication was greatly affected by axillary bud position: Productivity of multiple shoots were decreased in the order of top, mid and basal explants respectively. The best shoot multiplication (mean 6.1 shoots per explant) was obtained on WPM medium containing $1.0mg/{\ell}$ BAP and $0.1mg/{\ell}$ NAA using basal explant after 4-week-culture. Rooting was also greatly influenced by position. Its percentage was increased in the order of top, mid and basal explant respectively. Root initiation was better and more rapid on 1/2MS medium than GD medium. High rooting percentage (100%) was obtained on 1/2MS medium containing $0.2mg/{\ell}$ IBA after 15 days culture. Sucrose concentrations did not effect on rooting. However root development and shoot growth were greatly affected by them. Root was developed shortly on 1-2% levels and shoot growth was getting retarded, whereas both of them did not show significant difference at 3-6% levels. Rotting was decreased on 7-8% levels gradually, but shoot and leaf condition was better than any other concentrations. Survival rate of rooted explants in pot was varied according to the position of explants. Seedlings of top part were survived up to about 50% but most of mid and basal part seedlings did not survive over 4 weeks even in high humidity condition. Seedlings in pots showed normal growth over 10 months but most of them showed the condition of premature leaf shedding.