• Korean Journal of Medicinal Crop Science
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• v.23 no.4
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• pp.311-318
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• 2015

This study had been conducted to investigate the effect of some plant growth regulators inducing fruit enlargement and optimal harvest time in Sageretia thea. Two hundred fifty $mg/{\ell}$ mepiquat chloride treatment, $1mg/{\ell}$ thidiazuron treatment on full bloom, and $200mg/{\ell}$ gibberellic acid treatment on 7 days before full bloom resulted in the increase of 21.7% in weight, and $200mg/{\ell}$ gibberellic acid treatment 7 days before full bloom, 10$mg/{\ell}$ forchlorfenuron treatment 14 days after full bloom, and $1mg/{\ell}$ thidiazuron treatment on full bloom also brought about positive effects on the enlargement of the fruit, increasing 6.3%, 6.3% and 8.1% in its transverse diameter, respectively. Furthermore, the effects of the plant growth regulator treatments on the harvest time of Sageretia thea were determined as follows: the increase in the optimal harvest time of 57.2 - 75.4%, shorter maturation period, by the treatments with $500mg/{\ell}$ mepiquat chloride 7 days after full bloom, $100mg/{\ell}$ gibberellic acid treatment on full bloom, $2.5mg/{\ell}$ forchlorofenuron 7 days after full bloom and $2mg/{\ell}$ thidiazuron treatment 7 days before full bloom; and the greater effects of plant growth regulator treatments on the fruit maturation in the following order, gibberellic acid > thidiazuron > forchlorofenuron > mepiquat chloride. The results of this study are expected to be used as a reference data to develop Sageretia thea as a new local specific crop for Jeju island.

• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.199-205
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• 2022

BACKGROUND: The freezing injury by pruning can be reduced by suspending pruning work when severe cold weather (-23 to -49℃) is forecast. Minimum air temperature of the study area, Gunwi region at February 3, 2012 was -21.9℃, and the subzero temperature continued until April 8, 2012. This study was conducted in two years to investigate the effect of delaying winter pruning until full bloom on shoot growth and fruit quality of 'Fuji'/M.9 apple trees. METHODS AND RESULTS: The time of pruning were March 26 for dormant, April 3 for bud break, and May 2 for full bloom. The winter pruning at full bloom significantly reduced fruit weight for two years compared with the control (winter pruning at dormant), and shoot growth was reduced only in the following year. There was no significant effect of delaying winter pruning at bud break on soluble solid content, fruit red color, return bloom, and pruning weight for two years compared with the control. CONCLUSION(S): These results indicated the delaying winter pruning at bud break of 'Fuji'/M.9 apple tree did not offer any disadvantage over comparable dormant pruning, since the fruit quality was not affected. The delayed pruning at full bloom resulted in decreased fruit weight, though shoot growth, fruit quality, and return bloom were not affected by the delayed pruning. So, the delayed pruning should be considered carefully only for the fruit tree orchards in diseases.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.55-66
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• 2014

This study has been conducted to investigate the treatment time and concentration of GA₃ solution dipping for labor saving in 'Campbell Early' grapevine. The rachis growth at harvest was reduced by GA₃ solution dipping before 5 days flowering, and increased significantly by GA₃ solution dipping treatment at full bloom and after 5 days full bloom. GA₃ 5, 10, 20 mg·L^-1 dipping treatment before 5 days flowering and GA₃ 20 mg·L^-1 treatment of full bloom and after 5 days full bloom showed a rachis twist phytotoxicity symptom. The optimum GA₃ concentrations for rachis growth promotion without phytotoxicity were 5 mg·L^-1 and 10 mg·L^-1. The degree of compact berry, bloom, skin color, SSC and acidity at harvest by GA₃ solution dipping treatment time between concentration were not different from those of control. But the fruit berry weight was decreased by before 5 days flowering treatment when compared with control. There were no differences in full bloom and after 5 days full bloom treatment. The occurrence percent of berry cracking at before 5 days flowering and after 5 days full bloom treatment were significantly increased by GA₃ treatment. The bitter rot occurrence of berry at harvest was not affected by GA₃ treatment. Total rachis length of fruit cluster was increased by full bloom and 5 days after full bloom treatment. The length of rachis increased without reference to them position at full bloom and 5 days after bloom treatment. Accordingly, GA₃ 5 mg·L^-1 solution dipping treatment at full bloom and 5 days after full bloom were can be effectively for rachis growth promotion.

• Journal of Plant Biotechnology
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• v.36 no.2
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• pp.179-183
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• 2009

To understand the effect of reactive oxygen species (ROS) on floral senescence in Hibiscus syriacus L., we have investigated change in relative water potential, malondialdehyde (MDA) content, H_2O_2 content and the activity of antioxidative enzymes in the petals during flower opening and senescence. Hibiscus flowers were achieved full bloom at early morning and started to in-rolling and showed petal in-rolling over than 50% at 24 h and 36 h after full bloom, respectively. The flower was a decrease in fresh weight by 30% and showed water loss with floral senescence. MDA content and activity of antioxidative enzymes such as APX, GR and CAT were showed no significant change until 36 h after full bloom. In the flower 48 h after full bloom that showed complete petal in-rolling and wilting, however, activity of antioxidative enzymes and H_2O_2 content was greatly increased as compared with 0 h after full bloom. These results suggest that reactive oxygen species are related to accelerating the later senescence more than inducing the early senescence during Hibiscus flower senescence.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.493-498
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• 2016

This study was conducted to investigate the effect of environment factors on full bloom stage and fruit width in four peach cultivars. The average temperature in March was the main factor to determine the date of full bloom in 'Kurakatawase'($-0.6871^*$) and 'Changhowon Hwangdo'($-0.5270^*$). The fruit growth curve after 35 days from full bloom was the double sigmoid shape in 'Changhowon Hwangdo' cultivar. Environmental factors affecting fruit width were mean diurnal range(BIO2) and temperature annual range(BIO 7) in 'Kurakatawase', growing degree days(GDD) after 30 days from full bloom and July precipitation in 'Yumyeong', and annual mean temperature(BIO1), BIO7, and July precipitation in 'Kawanakajima Hakuto'. Of these, major environmental factors affecting fruit width in more than two cultivars were BIO7 and July precipitation.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.549-554
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• 2011

The effect of full bloom date and growing season weather on harvesting date of 'Niitaka' pear (Pyrus pyrifolia) in Naju province and the model of multiple linear regression for predicting the fruit growing days was studied. Earlier year in full bloom date, the harvesting date tended earlier but fruit growing days tended longer. Mean and coefficient of variation of fruit growing degree days (GDD) accumulated daily mean and maximum temperature at the base of $0^{\circ}C$ from full bloom date to harvesting date was 3,565, 2.9% and 4,463, 2.5%, respectively. Fruit growing days was not correlated with the fruit GDD accumulated daily mean and maximum temperature at the base of $0^{\circ}C$ in each month but highly correlated with GDD accumulated daily meteorological factors at days after full bloom date. Especially, it was highly negatively correlated with GDD accumulated daily mean and maximum temperature at the base of $0^{\circ}C$ from $1^{st}$ day after full bloom to $60^{th}$ day. The determination coefficient ($r^2$) of multiple linear regression model by full bloom date, GDD accumulated daily mean and maximum temperature from $1^{st}$ day after full bloom to $60^{th}$ day for predicting fruit growing days was 0.7212. As a result, the fruit growing days of 'Niitaka' pear in Naju province can predict with 72% accuracy by the model of multiple linear regression.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.368-372
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• 2000

The fruit structure of 'Fuji' apples from full bloom to maturing was observed from 1997 to 1998. Cell division period of the fruit was found to be 4 to 5 weeks after full bloom. Vascular bundles in the inner part of the fruit skin which were not described in the books illustrating apple fruit structure was observed, as they were tentatively named as outer vascular bundles (OVB), and another vascular bundles were also observed newly in periphery of locules, as they were tentatively named as inner vascular bundles (IVB). In the observation of the inner epidermis (IE) in the inner part of the locules on 2 days prior to full bloom, the guard cells were observed and these were disappeared in the observation made 2 days later, i.e. on full bloom. The formation of fruit skin was observed at the microscope 65 days after full bloom and the number of cell which organized the fruit skin did not change from this time to maturation period. Tannin which is mainly in the fruit skin changing from continuously during fruit growth, specially the tannin of epidermis disappeared completely 100 days after full bloom stage, and then constituted again. Starch was not almost found out in cell division period of fruit from full bloom stage after this time it constituted much at flesh part and decreased at maturation period. Epidermis was developed by uniform cells of a layer the cell of epidermis constituted irregularity after pigmentation stage, the organization of fruit was not close because the very big intercellular space constituted at hypodermis and flesh structure.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.2
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• pp.114-118
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• 2002

This study was conducted to estimate the full bloom stage of the Fugi apple at e in different elevations at Chungju area. The lapse rate of air temperature related to the elevation in Chungiu area was calculated and applicated to estimate the full bloom stage of the Fugi apple cultivar at different elevations. The data far nine levels of elevations at 150, 250, 359, 555, 710 m with the direction of S-W in the Mt. Gyemyong and at 165, 255, 415, 545 m with the direction of N-W in the Mt. Nam were analyzed. The lapse rate range were 0.89$^{\circ}C$ per 100 m elevation in the Mt. Gyemyong and 0.74$^{\circ}C$ in the Mt. Nam respectively. The difference of full bloom stage different elevations was 4 to 5 days per 100 m and its range was from April 29th at 100 m to May 10th at 400 m.

• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.133-144
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• 2015

A study was conducted to examine treatment method, proper concentration, and treatment time of gibberellin(GA₃) for human labor saving at harvest in 'Campbell Early' grapevine. Fruit berry thinning reduced labor by GA₃ 40ppm treatment of 5 days prior to full bloom, and, at GA₃ 10, 20, and 40ppm during full bloom, by 14.27~19.15 minutes/tree. Therefore, although labor was reduced by dipping treatment at 40ppm of 5 days prior to full bloom and 20 and 40 ppm during full bloom, severe shattering was observed at 40ppm dipping treatment, and soluble solids decreased, which suggests difficulty with commercialization. The result suggests that proper time and concentration of GA₃ fruit cluster dipping treatment at full bloom and 10 and 20ppm, respectively.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.166-172
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• 2019

BACKGROUND: Increase in the ratio of small berries in blueberry production decreases the farmers' profits due to weakening market competitiveness and lowering harvest efficiency. One of the reasons for increased small berries is over fruit-load. For improving productivity and competitiveness of blueberry in Korea, hand-thinning can be applied to increase fruit quality before the developing adequate chemical thinning methods. This study was conducted to investigate the proper timing and methods for floral buds thinning in rabbiteye blueberry. METHODS AND RESULTS: Eight years old bushes of rabbiteye bluberries 'Brightwell' as a primary cultivar and 'Powderblue' as a pollinizer were used for this study. Fruit size distribution by leaf-to-fruit ratio was investigated by counting the number of leaves and fruits in canes of 127 'Brightwell' plants whose fruit set varied. Fifty percent of flowers/floral buds were removed in four different floral buds stages such as bud swell, late pink bud, full bloom, and petal fall, and the consumed time for thinning and fruit characteristics were recorded to investigate the effect and proper timing of floral buds thinning. Fruit weight and soluble solids content tended to increase in proportion to leaf-to-fruit ratio and the production of the number of fruits less than 13 mm in diameter decreased when leaf-to-fruit ratio was more than 2.5. Manual floral buds thinning by hands was fastest in full bloom stage and slowest in bud swelling stage. In all cultivars, fruit size was significantly smaller in non-thinning treatment than thinning, and there was, however, no significant difference in total fruit yield. The number of fruits less than 13 mm in diameter increased in both cultivars as floral buds thinning was delayed. Consumed time for picking 90% berries out of total berries per bush was shortest in full bloom stage thinning in 'Brightwell' and bud swelling, full bloom thinning in 'Powderblue'. These were 25 and 20 days faster than no thinning, respectively. CONCLUSION: Although the effect of floral buds thinning varied depending on the cultivars, our results confirmed that floral buds thinning was effective for the early intensive harvesting and the increase of the large fruit ratio and the harvesting productivity. Also, in order to increase thinning efficiency, it is recommended to remove the flower buds before the full bloom stage.