• Agribusiness and Information Management
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• v.6 no.1
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• pp.1-11
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• 2014

The purpose of this study is to develop the growth prediction model that can predict growth and development information influencing on the production of citrus fruits. The growth model was developed to predict the floral leaf ratio, number of fruit sets, fruit width, and overweight fruits depending on the main period of growth and development by considering the weather factors because the fruit production is influenced by weather depending on the growth and development period. To predict the outdoor-grown citrus fruit production, the investigation result for the standard farms is used as the basic data; in this study, we also understood that the influence of weather factors on the citrus fruit production based on the data from 2004 to 2013 of the outdoor-grown citrus fruit observation report in which the standard farms were targeted by the Agricultural Research Service and suggested the growth and development information prediction model with the weather information as an independent variable to build the observation model. The growth and development model for outdoor-grown citrus fruits was assumed by using the Ordinary Least Square method (OLS), and the developed growth prediction model can make a prediction in advance with the weather factors prior to the observation investigation for the citrus fruit production. To predict the growth and development information of the production of citrus fruits having a great ripple effect as a representative crop in Jeju agriculture, the prediction result regarding the production applying the weather factors depending on growth and development period could be applied usefully.

• Animal cells and systems
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• v.2 no.4
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• pp.435-438
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• 1998

In the present study, we have examined the crossability of four species in the A. jaluense complex to provide additional information on their delimitation and levels of differentiation. Crosses between diploid A. chiisanense and the tetraploid species including A. jaluense s. str., A. triphyllum, and A. pseudoproliferum yielded no fruit- or seed-set, indicating that the former species is reproductively completely isolated from the latter three species. In interspecific crosses between the tetraploid species, combinations involving A. jaluense s. str. resulted in much reduced fruit- and seed-set, indicating that A. jaluense s. str. is more or less reproductively isolated from the other tetraploid species. However, crossing data revealed the absence of reproductive isolation between A. triphyllum and A. pseudoproliferum These results strongly support the relationships that have been previously suggested for the A. jaluense complex on the basis of morphology, chromosome number, and flavonoid chemistry.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.207-212
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• 2018

BACKGROUND: Recently, the need for a method to cultivate 'Haryejosaeng' Satsuma mandarin has been increasing. However, there is limited information available as this is a new Satsuma mandarin cultivar, which was bred by the RDA in 2004. Many farmers who cultivate this cultivar follow the cultivation method similar to that used for 'Miyagawa' Satsuma mandarin, and suffer low production of optimum-sized fruits. METHODS AND RESULTS: This study was conducted to find out the optimum ratio of leaf-to-fruit for the stable production of high quality 'Haryejosaeng' Satsuma mandarin fruits in a non-heated plastic film house. Seven-year-old 'Haryejosaeng' Satsuma mandarin trees were used in the study. Before the treatment, the leaf-to-fruit ratio ranged from 5.7 to 17.9. The treatments included 10, 20, 30, and 40 leaves per fruit. The fruits were removed if over fruiting was observed at day 60 after full bloom. We investigated the fruit size and quality on the day of harvest. Flowering and fruiting patterns in each treatment were recorded for the following year. In the experiments, the flower-to-leaf ratio was 1.12 to 1.74. As the leaf-to-fruit ratio decreased, the fruit size and weight also decreased. Contrarily, the higher the ratio of leaf-to-fruit, the higher fruit size and weight were. It was noted that the ratio of 20:1 was ideal to produce the M grade optimum-sized Satsuma mandarin fruits on the day of harvest. However, higher ratio might result in fruits weighting above 100 g. There was no difference among the treatments in terms of fruit quality, such as total soluble solid contents, titratable acid, and color. In the subsequent years, flowering and fruiting in the treatments were lowered when the leaf number per fruit was 10, but they were improved when the leaf number per fruit was above 20. CONCLUSION: Based on the above results, the optimum ratio of leaf-to-fruit was found to be 20:1 for flowering and fruiting of 'Haryejosaeng' Satsuma mandarin. It is important that optimum ratio of leaf-to-fruit is set as a standard to produce good grade and quality of 'Haryejosaeng' Satsuma mandarin fruits.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.340-345
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• 2014

Since the moisture content (MC) of growing medium closely related with the crop transpiration, the MC should be included to the environmental factors to be considered for irrigation control in soilless culture. The objective of this study was to analyze the transpiration of paprika plants using daily mean solar radiation (RAD) and vapor pressure deficit (VPD) as well as the growth of the plants at different MCs of rockwool growing media. The starting points of irrigation were controlled by a moisture sensor with minimum set points of 40%, 50%, and 60% of MCs. The canopy transpirations were measured for 80 to 120 days after transplanting and analyzed. The transpirations were well regressed with a combination of both RAD and VPD rather than daily mean RAD only under the controlled MCs. The transpiration at 60% MC was higher than those at 50% and 40% MCs. Leaf area, leaf fresh and dry weights at 60% MC were higher than those at 50% and 40% MCs while the number of leaves had no significant difference among the MCs. There were no significant differences in number of fruits and fruit size among all the MCs, while fruit weight was significantly lower at 40% MC than other treatments. Fresh and dry fruit yields were the highest at 60% MC. Therefore it was concluded that the transpiration was affected by the MC of rockwool growing medium and the minimum set point of 50-60% MC of rockwool growing medium gave better effects on the growth of the paprika plants.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.287-293
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• 2007

The pollinating activity of bumblebee, Bombus ignitus was investigated at the blossom of Peach [Prunus persica (L.) Batsch] planted in vinyl house. The major time of foraging activity by B. ignitus was between 08:00 and 7:00, and the peak time of pollinating activity by B. ignitus was 11 :00 in the peach vinyl house from February 28 to March 5 in 2002. The rate of fruit set and the rate of marketable fruit by foraging activity of B. ignitus were much better than artificial pollination, and the effect of labor reduction by the pollinating activities of B. ignitus released against th ε artificial pollination was took remarkable profits over 93%. Therefore, the foraging activity of B. ignitus in peach vinyl house brought satisfactory results among the rate of fruit set, the rate of marketable fruit and the effect of labor reduction against the artificial pollination.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.294-298
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• 2012

In sweet cherry (Prunus avium L.) growing there are several severe problem which have to be overcome to produce highly graded fruits because of fruit rots and fruit crackings, if there is frequent precipitation during immature fruit step and picking season. In order to reduce fungicide sprayings and produce qualified fruits in areas with rainy season like as South Korea, rain-sheltered growing is necessary absolutely. Sweet cherry blooms early to medium April in southern area of South Korea. If we depend on honeybees (Apis mellifera) distributed in natural ecosystem, it is not easy to get normal fruit-set every season because of low temperature around blooming time. And also bee keepers seldom sell honeybee hives as a pollinator during spring, instead they keep honeybee hives to get honey. Recently use of B. terrestris as a pollinator of cherry tomato, oriental pumpkin etc. grown in protected cultivation system increase abundantly. Therefore, in this study we studied B. terrestris as an alternate of honeybee to pollinate sweet cherry grown in rain shelter. In part of foraging activity B. terrestris shows staying on a cherry flower for about six second and visiting frequency of 11 flowers per minute. However A. mellifera stayed about 15 second on a flower and visited 4~5 flowers per minute. There were no significant difference in fruit-setting rate and fruit characteristics after using B. terrestris and A. mellifera as pollinators of sweet cherry. Consequently there is no negative effect when we use B. terrestris as an alternate pollinator of A. mellifera in sweet cherry cultivation under rain shelter.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.424-432
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• 2016

This experiment was carried out to compare growth and fruit setting characteristics in ten winter-planted paprika (Capsicim annuum L.) cultivars. Five red line paprika cultivars ('Maduro', 'Maranello', 'Nagano', 'Sirocco' and 'Special') and five yellow line paprika cultivars ('Coletti', 'Sven', 'Thialf', 'Volante' and 'Zagato') were used for this study. The experiment was performed for 42 weeks, from winter of 2013 to autumn of 2014. Based on the growth stages of paprika, growth characteristics were investigated six times, and each investigation was categorized from group 1 through group 6. The relative internode ratio showed a normal range at the early growth stage, but tended to gradually decline as growth progressed. This trend was greater in red line paprika than in yellow line paprika. Among the cultivars used for this experiment, 'Special' and 'Zagato' showed growth inhibition, whereas 'Maranello' and 'Volante' kept a balanced growth during summer cultivation. The fruit set percentage in yellow paprika was 10.8% higher than in red paprika, while the number of branches in yellow paprika was 4.1% less than in red paprika. When measured after the full fruiting age, from June to July, the number of fruit set in group 4 was much lower in 'Sirocco' and 'Coletti' than in any of the other cultivars, indicating that they were more sensitive to the growth environment during the rainy season. These findings suggest that 'Maranello', 'Nagano', 'Sven', 'Thialf', and 'Volante' could be effectively used for summer cultivation in a high-plastic-film greenhouse, and 'Maranello', 'Special', 'Volante', and 'Zagato' could be good candidates for a low-plastic-film greenhouse.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.83-88
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• 2005

A study was conducted on three pollination methods on oriental melon(sageageol-ggul) grafting with pumpkin(seongjutozoa) for the labor-saving and to improve fruit set. Fruit weight, flesh thickness and fruit setting rate of oriental melon were greater in growth regulators treatment than those of pollinated by bees. Sugar content and hardness of fruits pollinated by bees were higher than those of by growth regulators. From the last ten days of the February to the first ten days of the March, fruit setting rate was $95\%$ in fruit setting growth regulators, whereas it was $46\%$ and $45\%$ in pollinated by honey and bumble bee, respectively. After the middle of March, the percentage of fruit setting was >$98\%$ in all the pollination methods. The cultivation under plastic houses of oriental melon, suitable fruiting time far the pollination by bees was decided after middle days of the March. Chromaticity and especially the value of 'a' of fruit of oriental melon pollinated by bees were higher than those of growth regulators. The percentage of fermented fruits of bee pollinated and growth regulators treated was $6.7\~9.1\%\;and\;28.1\%$, respectively. The weight of 100 seeds of bees pollinated were higher than that of growth regulators. The more increased the weight of 100 seeds the less appeared the rate of fermented fruits. The percentage of marketable fruits of the honey and bumble bee pollinated and that of growth regulators treated was $82\%,\;80.3\%\;and\;62.5\%$, respectively. The decreasing rate of fruit weight during storage of bees pollinated was less than those of growth regulators. In these results, the introduction of honey bee and bumble bee for the pollination of oriental melon was able to labor-saving of fruit set and increase of fruit quality.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.942-947
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• 2010

In the present study, pollen tube growth and fruit set in Asian pear ($Pyrus$ $pyrifolia$) were examined upon the mechanical damage on the stigma and style following the artificial pollination. When the upper middle part of style was cut off at 48 h after the artificial pollination, pollen tube grew to the middle of the style and the subsequent pollen tube elongation and fruit set normally occurred. When the style was cut off before the pollen tube reached the middle of the style, however, no pollen tube elongation and fruit set occurred. With the pollen tube elongation through the style, callose plugs at the basal part of the pollen tube were formed to the direction of the elongation at regular intervals. When the upper part of pollen tube attached pollen grain was cut off, however, callose plugs were formed defectively in the pollen tube, and the pollen tube opened and lost their turgor pressure. These facts might be the reason for the ceased or delayed pollen tube elongation and ultimately the failure of the fertilization.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.360-367
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• 2020

BACKGROUND: The productivity and quality of blueberry (Vaccinium ashei Reade) greatly depend on the number of fruits in a plant. Especially, fruit set more than appropriate number negatively affects productivity and marketability due to the increased number of small fruits and delayed harvest time. This study was conducted to investigate proper timing and concentration for applying chemical blossom thinners such as ammonium thiosulfate (ATS) and UREA. METHODS AND RESULTS: ATS at 1.25% and 1.50%, and UREA at 6% and 8% were applied in four developmental stages, bud swell, pink bud, full bloom and petal fall. Fruit thinning rate was calculated based on the number of fruits harvested divided by that of flowers before applying blossom thinners. Ratios of leaf to flower and leaf to fruit were calculated based on the number of fully developed leaves in 25 days after full blossom divided by that of flowers or fruits, respectively. Chemical injury of leaves was investigated by calculating the number of leaves with chemical injury divided by the total number of leaves. Fruit thinning rates were 48% and 66% for UREA treatments at 6% and 8%, respectively, and 49% and 62% for ATS treatments at 1.25% and 1.50%, respectively, in the full bloom stage. In the petal fall stage, fruit thinning rates were 18% and 24% for UREA treatments at 6% and 8%, respectively, and 49% and 35% for ATS treatments at 1.25% and 1.50%, respectively. Leaf to fruit ratio (L/FR) increased by 109% and 188% compared to leaf to flower ratio in ATS treatments at 1.25% and 1.50%, respectively, and L/FR increased 93 and 196% in UREA treatments at 6% and 8%, respectively, in the full bloom stage. In the petal fall stage, leaf to fruit ratio increased by 60% to 100% in ATS treatments, but did not significantly differ from the control in UREA treatments. Fruit harvest was delayed in all treatments of all developmental stages except for 1.5% ATS and 6% UREA treatments at the petal fall stage, whose fruit harvest was two or three days faster than the control. CONCLUSION: The application of ATS and UREA for blossom thinning should be in the petal fall and full bloom stages for early and late harvest, respectively. Considering chemical injury, integrated harvesting and fruit size, however, it is appropriate to apply ATS at 1.5% in the petal fall stage to increase fruit productivity and quality in blueberry.