• Korean Journal of Soil Science and Fertilizer
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• v.46 no.2
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• pp.136-141
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• 2013

Lowering tree height has been a key practice for efficient management of persimmon orchards. This experiment was conducted to assess whether fertilization rates could be reduced after lowering the tree height by heavy pruning. Twelve-year-old 'Uenishiwase' persimmon trees were lowered to 2 m from over 3 m by severe dormant pruning, and then conventional fertilization rate was applied to some trees in April (N 224 g, $P_2O_5$ 172 g, and $K_2O$ 172 g per tree), June (N 112 g and $K_2O$ 99 g per tree), and October (N 112 g and $K_2O$ 99 g per tree). At the same time, 1/3 or 2/3 of the conventional rate and none were applied to other trees, respectively. Non-application decreased shoot length and reduced number of unnecessary secondary shoots by 39% compared with the conventional rate, not affecting yield and weight, color, firmness, and soluble solids of fruits. No significant difference was also found in the yield and the fruit characteristics among the trees fertilized with different rates. Concentrations of soluble sugars, starch, N, and K of dormant shoots in March of the following year were not significantly changed by the different treatments of the previous year. There was no significant difference of shoot growth and yield among the treatments the following year when the same fertilization rate was supplied to all the trees. Results indicated that fertilization rate could be reduced to less than 1/3 of conventional rate to save the cost and stabilize shoot vigor when tree height is lowered by severe pruning.

• Journal of Forest and Environmental Science
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• v.35 no.4
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• pp.223-231
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• 2019

Castanopsis indica (Sil Batna) is an ecologically valuable multipurpose indigenous tree species of Bangladesh. Considering its high value but poor natural regeneration due to seed dormancy, the authors conducted an experiment at the Institute of Forestry and Environmental Sciences Chittagong University (IFESCU) during 2012-2013 to find out effective pre-sowing treatments. Ten pre-sowing seed treatments were applied on mature, even-sized seeds namely-control; sandpaper rubbing; nail clipping; immersion in normal water (at room temperature: 24℃) for 24 hrs., 48 hrs. and 72 hrs.; immersion in hot water (80℃) for 1 minute; soaking in 10% dilute H₂SO₄; soaking in 10% HCl for 5 minutes; and sowing in propagator house. Seeds sown after sandpaper rubbing at the distal end revealed best performances by providing highest germination percent (66.7%), germination energy (30%), germination index (0.17), germination rate (0.0145), germination value (30%) and plant percent (66.7%) within shortest period (38 days). The treatment also produced most vigor seedlings with 20.9 cm shoot height, 15 node number, and largest leaves (11.1 cm×2.9 cm). Hence, it is recommended to adopt sandpaper rubbing method for maximum germination and quality seedlings.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.932-940
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• 2015

One of the main factors restricting production of triploid seedless watermelon is poor germination due to weak embryos, thick seed coats, and larger air spaces. This study was carried out to investigate the priming effects of different concentrations of chemicals, including hydrogen peroxide ($H_2O_2$), fusicoccin, and gibberellic acid (GA) on germination and seedling uniformity of triploid watermelon (Citrullus lanatus). Three commercial triploid cultivars, Seedless Plus, Sinus, and Sizero, were pretreated with water and different levels of $H_2O_2$ (2 and 4%), fusicoccin (FC: 1, 5, and $10{\mu}M$), and GA (1, 5, and $10{\mu}M$). The present findings helped to find optimal priming conditions for improving germination of triploid watermelon. Treatment with $5{\mu}M$ GA and hydropriming helped to break seed dormancy, enhancing the final germination percentages in all triploid cultivars and increasing the germination index in Sizero. These seed-priming treatments could be used on large scale for industrial applications. Moreover, hydropriming provides a simple, effective, and costless method to improve seed germination and seedling vigor of Sinus and Sizero varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.368-374
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• 1985

This study was carried out to obtain the basic information for the shortening of emergence period of ginseng by treatment of growth regulators. Seedlings that removed and non-removed bud sac were treated at 10, 50 and 100ppm of GA$_3$, Kinetin and 2,4-D in early December, and investigated the characteristics of new bud emergence and growth vigor in 2-year-old ginseng. GA treatment showed the most desirable effects in shortening of emergence period of new bud, and elevating its emergence rate with increasing of the GA concentration. In addition, GA treatment especially accelerated the growth of stem and petiole length and early finished the growth of aerial parts of ginseng. On the other hand, root weights were mainly increased by formation of a lot fine roots in GA 50, 100ppm plots.

• Korean Journal of Environmental Biology
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• v.18 no.2
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• pp.247-253
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• 2000

In order to investigate the stimulatory effect(hormesis) of low dose gamma-radiation on the seeding growth of old seeds with respect to antioxidant defense systems, various doses of gamma radiation to the 5-year-old dried seeds of Chinese cabbage (Brassica campestris L. cv Sulin eockaei). Compared to the new, 1-year- old seeds, old seeds irradiated by low does gamma radiation in the range of 1-2 Gy showed vigor growth as revealed by statistically significant increases both in the germination rates and the leaf size and fresh weight. Further, seedlings grown from seeds treated by low dose gamma radiation showed higher peroxidase and catalase activities than non-treated seedlings. These results suggest that the antioxidant defense systems could be closely related to the stimulatory effects of low dose radiation. [antioxidant enzyme, chinese cabbage, gamma radiation, germination rate, hormesis]

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.92-97
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• 1989

The study has carried out to investigate the possibility of application of the emerged-peduncle at the 2 year -old plant for ginseng breeding. In the 2 and 3 year-old plant, growth habits of aerial parts of plants that had the inflorescence showed higher vigor in leaf length, number of leaves, rate of fruitage and fertility, and roots yield than those of non-inflorescence. Generally, characteristics such as stem diameter, stem length, leaf length and number of leaves showed highly significant positive-correlation with root weight and fruitage. The trends of characteristics of plant that has inflorescence at the 2 year-old plant was shown one-year faster pattern than the plant that has non-inflorescence. As these results, selection of the plants which have inflorescence at the 2 year-old plant will provide valuable aid for ginseng breeding.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.335-339
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• 1995

This experiments were carried out to develop for food in some plants seeding. Plant materials were Raphanus sativus, Perilla frutescens var. acuta, Perilla frutescens var. japonica, Scutellaria baicalensis, Angelica dahurica, Angelica gigas, Ligusticum acutilobum, Peucedanum japonicum, Platycodon grandiflorum, Codonopsis lanceolata, Allium monanthum and Fagopyrum esculentum. The results obtained are summarized as follows ; germination rate was the highest in Raphanus sativus and germination vigor was excellent in Perilla frutescens var. acuta Total overall acceptability was the best in Perilla frutescens var. acuta

• Mycobiology
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• v.38 no.2
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• pp.113-117
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• 2010

Trichoderma strains were evaluated under field conditions to assay their efficacy in suppressing Alternaria fruit rot disease and promoting chili plant growth. The experiment was conducted at the Botanical Garden, Rajshahi University, Bangladesh from July 2006 to March 2007. Application of Trichoderma harzianum IMI 392432 significantly (p = 0.05) suppressed the disease compared to Alternaria tenuis (T2) treatment and improved both growth and yield. The treatment T4 (T. harzianum IMI-392432 + A. tenuis) was most effective in reducing disease percentage (72.27%) compared to A. tenuis (T1) treatment. The highest seed germination rate (85.56%) and the highest growth and yield (12.5 g/plant) was also recorded in the same treatment (T4), followed by T5 (T. harzianum IMI-392433 + A. tenuis), T6 (T. harzianum IMI-392434 + A. tenuis), T2 (T. virens IMI-392430 + A. tenuis), and T3 (T. pseudokoningii IMI-392431 + A. tenuis) treatment, while single treatment with A. tenuis significantly decreased these values.

• Korean Journal of Plant Resources
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• v.36 no.6
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• pp.580-587
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• 2023

Androsace septentrionalis is a grass species restricted to North Korea; however, it is at the brink of extinction due to habitat loss and environmental changes caused by natural disasters and anthropogenic activities. This study was conducted to characterize the dormancy conditions of A. septentrionalis in an effort to conserve this North Korean plant resource. For this purpose, the morphological characteristics and vigor of A. septentrionalis seeds were examined, and its germination characteristics under different temperature conditions (15/6℃ and 25/15℃ ), low-temperature stratification, and gibberellin (GA₃) treatment were determined. The results revealed that A. septentrionalis exhibits non-deep type morpho-physiological dormancy, and low-temperature stratification treatment was not effective in breaking the dormancy of A. septentrionalis seeds. Meanwhile, GA₃ treatment significantly increased the mean germination time, rate, and speed of the seeds. The optimal conditions for the germination of A. septentrionalis seeds were 25/15℃ fluctuating temperature and 500 mg·L¹ GA₃ treatment. The results of this study are useful for the mass propagation of A. septentrionalis.

• Journal of Korean Society of Forest Science
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• v.66 no.1
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• pp.74-78
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• 1984

The highest cutting ratio and the best growth performance of the P. alba, P. alba ${\times}$ P. glandulosa and P. glandulosa were at -0.05 bars of soil water potential (${\Psi}_s$). Their growth and rooting ability of cuttings were better in suitable soil moisture contents, 19.650, but were worse in low soil moisture contents, 11.41% and 16.66%, respectively. Specially, P. alba ${\times}$ P. glandulosa appeared hybrid vigor in high soil water potential (${\Psi}_s$= -0.05 bars) but not appeared it below ${\Psi}_s$ = -0.5 bars. It is believed that P. glandulosa is a natural hybrid between P. davidiana and P. alba in view of morphological characteristics. Aspen, normally, does not have the rooting ability of cuttings, however, P. glandulosa showed the rooting ability, though the ratio was low, 23%. It is estimated that this rooting ability was originated from P. alba. In addition, its growth rate was between P. alba and P. davidiana, and the sensitivity of water requirement for the growth was also really equal to P. alba. This facts prove P. glandulosa to be natural hybrid between P. alba and P. davidiana.