• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.3
• /
• pp.310-323
• /
• 1989

This study was carried out to find out the difference of ripening and growth characteristics among the different florets in same panicle. There were 2 different transplanting date (May 25 and June 10) and 6 varieties were used. Physiological ripening period, ripening speed, 1000 grain weight, germination speed and grain quality were studied among the different florets (1, 5 and 8 days after heading) in same panicle. Physiological ripening period was long in late transplanting, late flowering floret, and late varieties by 3-9 days in Japonica. Ripening speed and 1000 grain weight were high in early transplanting and early flowering florets. There was positive correlation among the ripening speed, 1000 grain weight and a average temperature but negative correlation between the ripening and physiological ripening period. Germination speed was excellent in early flowering floret after heading. There was difference in amylose content within varieties and different flowering grains and there was significant correlation between grain quality and meteorological factors in some varieties.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.90.2-91
• /
• 2003

In commercial greenhouses, senescent flower petals or flowers of vegetables such as tomato, strawberry, hot pepper and zucchini squash were blighted to be removed from fruits within five days after spraying of Trichoderma harzianum YC459 (TORY), a biocontrol agent for the gray mold rot of vegetables caused by B. cinerea The mechanism for selective colonization of senescent floral tissues by T. harzianum YC459 was elucidated using fresh and senescent (Hays and 14days after flowering, respectively) floral tissues of zucchini squash (Cucurbita moschata Duchesne). The spores of T. hrzianum YC459 were produced more on agar and liquid culture media supplemented with 5％ dry powder of senescent floral tissues than fresh tissues during 15days. Mycelial growth was also much better in the media with senescent tissues than with fresh tissues. Enzyme activities of amylase, polygalacturonase and cellulase in the liquid media which might be involved in the colonization of tissues by T. harzianum YC459 were compared. The activities of three enzymes were much higher in the media with senescent floral tissues than with fresh floral tissues reaching to the maximum during 9 to 12days of incubation. Based on the results, the removal of senescent floral tissues, a possible inoculum source of the pathogen, may be another mechanism for biocontrol of gray mold rot of vegetables by T. harzianum YC459.

• Journal of Applied Biological Chemistry
• /
• v.43 no.3
• /
• pp.152-155
• /
• 2000

The contents of various capsaicinoids viz. nordihydrocapsaicin (NDC), capsaicin (CAP), and dihydrocapsaicin (DHC) were determined in different parts of fruits (placenta, pericarps, seeds, and whole fruits) at different developmental stages after flowering and compared with the capsaicinoid synthetase (CS) activity. The capsaicinoid contents were very low up to 24 days after flowering (DAF), and there was a significant increase at 36 DAF in all parts of fruits. The enzyme activity of placenta increased to maximum at 24 DAF, and thereafter it gradually decreased. There were no significant amounts of enzyme activities in other parts of the fruits. In Subicho (inbred line) the content of DHC was slightly higher than CAP in all parts. of the fruits throughout the development stages of fruits, whereas in Chung Yang the CAP content was higher compared to the DHC content. The contents of total capsaicinoids in Chung Yang were also higher than Subicho. However, the crude enzyme extract obtained from Chung Yang led to the synthesis of DHC almost exclusively when the substrate, 8-methyl nonanoic acid, was added to the reaction mixture. Our results suggest that the composition of individual analogue of capsaicinoids depends upon the substrate available in the fruits.

• Journal of the Korean Society of Tobacco Science
• /
• v.3 no.2
• /
• pp.103-108
• /
• 1981

This experiment was carried out to investigate effects of soil moisture content on the growth of tobacco plant at early stage after transplanting. Soil moisture was controlled to be 30%, 45%, 60%, 75% and 90% of the maximum water holding capacity (38.7%), and treated for 10, 20 and 30 days. Budding flowering and topping were delayed in the 30% and 45% treatment where soil moisture was deficient. Plant height, number of leaves, and length and width of the largest leaf were the best in the 75% treatment for 10 days, and development of the root and top was the best also in the same treatment. As the duration of low soil moisture treatment prolonged, intercellular space , became small. Nitrogen and potassium of the cured leaf showed the highest value in 30% and 45% treatments. Nicotine content of the cured leaf was high in the 90% treatment, and reducing sugar content of that was high in the 75% treatment for 10 days.

• Journal of Bio-Environment Control
• /
• v.7 no.2
• /
• pp.109-115
• /
• 1998

This study was conducted to evaluate the growth and flowering responses of Eustoma grandiflorum cv. Azmasul, Azmahoon and Azmazo influenced by duration of storage at 1$0^{\circ}C$ of seedlings raised in warm season. The plants after cold treatment were cultivated in a glasshouse under natural day length with the minimum temperature of 12$^{\circ}C$. The stem thickness and number of leaves of Azmasul and Azmahoon were not affected by duration of cold treatment However, plant height, internode length fresh and. dry weights were significantly increased in the four-week treatment. In addition, four-week treatment increased flower weight and width. Bays to flowering of Azmasul and Azmahoon in four-week treatment were shortened by 20 days compared to the control or two-week treatment. Shoot growth and flower Qualify of Azmazo under the four-week treatment were promoted. Four-week treatment reduced the days to flowering of Azmazo by 31 and 36 days compared to the control and two-week treatment. The results of this study show that optimum duration for storage at l$0^{\circ}C$ for seedlings of Ewtoma grandiflorum cv Azmasul. Azmahoon and Azmazo grown in warm season is four weeks.

• Horticulture, Environment, and Biotechnology : HEB
• /
• v.59 no.6
• /
• pp.827-833
• /
• 2018

Plasma lighting systems have been engineered to simulate sunlight. The objective of this study was to determine the effects of plasma lighting on tomato plant growth, photosynthetic characteristics, flowering rate, and physiological disorders. Tomato plants were grown in growth chambers at air temperatures of $25/23^{\circ}C$ (light/dark period), in a $16h\;day^{-1}$ light period provided by four different light sources: 1 kW and 700 W sulfur plasma lights (1 SPL and 0.7 SPL), 1 kW indium bromide plasma light, and 700 W high pressure sodium lamp (0.7 HPS) as a control. The totaldry weight and leaf area at 0.7 SPL were approximately 1.2 and 1.3 times greater, respectively, than that of 0.7 HPS at the 62 days after sowing (DAS). The maximum light assimilation rate was observed at 1 SPL at the 73 DAS. In addition, the light compensation and saturation points of the plants treated with plasma lighting were 98.5% higher compared with HPS. Those differences appeared to be related to more efficient light interception, provided by the SPL spectrum. The percentage of flowering at 0.7 SPL was 30.5%, which was higher than that at 0.7 HPS; however, there were some instances of severe blossom end rot. Results indicate that plasma lighting promotes tomato growth, flowering, and photosynthesis. Therefore, a plasma lighting system may be a valuable supplemental light source in a greenhouse or plant factory.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.4
• /
• pp.327-332
• /
• 2010

This study was conducted to overcome the deliciousness by sex reversal in hemp plants. When female plants grown under long day length condition were transferred to short day length condition in 3th and 6th leaf stage, a few male flowers were formed and the gap of flowering days between sex reversed male and normal female flowers were around 10 days and 3 days, respectively. Although the flowering amounts were small, this short gaps of flowering days were enough for artificial pollination. When female plants grown under long day length condition were transferred to short day length condition just after treatment of silver nitrate in the vegetative stage, a great amount of male flower was formed and the gap of flowering days between sex reversed male and normal female flowers were only 1 to 3 days. The increased sex reversed male flowers and induced short gap of flowering days were adequate for natural wind pollination. When female seeds were cultivated, seed yield was 141 kg/10a, while it was 96 kg/10a when normal seeds cultivated.

• Horticultural Science & Technology
• /
• v.32 no.6
• /
• pp.812-818
• /
• 2014

Raising seedlings is important for fruit crops and is especially significant for strawberries as it accounts for 80% of their cultivation. However, there are few studies on raising seedlings of strawberries by hydroponics. Since strawberries show clear differences in growth characteristics based on cultivar, it is necessary to develop suitable fertilizer formula, concentration and pH for each cultivar, and also to examine the amount of nutrient feeding appropriate for each medium type. A key to raising seedlings of strawberries by hydroponics is the development of strategies to manage the concentration of nutrient solution. The mother plants of 'Daewang' strawberries were planted on hydroponics benches filled with cocopeat on March 28, 2012. Three nutrient solution treatments were employed during the term of raising seedlings: a type that supplied EC $0.6dS{\cdot}m^{-1}$ nutrient solution for 30 days and only water for 20 days [0.6 (30) + 20]; a type that supplied EC $1.2dS{\cdot}m^{-1}$ nutrient solution for 30 days and only water for 20 days [1.2 (30) + 20]; and a type that supplied EC $1.2dS{\cdot}m^{-1}$ nutrient solution for 50 days [1.2 (50)]. The plants were then planted on hydroponics benches filled with cocopeat on September 20, and managed with EC $0.6-0.8dS{\cdot}m^{-1}$ strawberry nutrient solution developed by Yamazaki. After planting, shoot growth, flowering rate and fruit quality of the first cluster were investigated. The petiole length, leaf length, leaf width and crown diameter showed the highest grown in the [1.2 (50)] treatment, followed by [1.2 (30) + 20], and then [0.6 (30) + 20], indicating that the higher concentration of nutrient solution was preferable for raising seedlings. However, the growth differences among treatments gradually disappeared as growth continued, and the crown diameter especially grew to exhibit almost no difference at all among treatments. The point of flowering came first in [0.6 (30) + 20], followed by [1.2 (30) + 20] and then [1.2 (50)]. The [0.6 (30) + 20] treatment showed much earlier flowering than other treatments, which implies that low-concentration nutrient solution may be beneficial to the flowering of 'Daewang' strawberries while raising seedlings. There was no statistically significant difference among treatments in fruit length, fruit diameter and fruit firmness. Fruit weight in [1.2 (50)] treatment was significantly higher than other treatments. However, soluble solids of fruit was the lowest in [1.2 (50)] treatment. Together, the results of this experiment imply that it is better to supply EC $0.6dS{\cdot}m^{-1}$ solution for 30 days and then supply only water for 20 days to adequately manage concentration of nutrient solutions during the period of raising seedlings of strawberries by hydroponics.

• Korean Journal of Weed Science
• /
• v.8 no.1
• /
• pp.23-27
• /
• 1988

This experiment was conducted to determine germination ability, life cycle, regrowth ability of Portulaca oleracea L. The newly harvested seeds from P. oleracea flowered before July 15 were able to germinate, but percent germination decreased markedly as the flowering time was later than July 15, showing no germination of seed collected at Sept. 12 which were flowered at August 30, 76.5% of seeds can be germinated in the light as seed stored in room condition for 90 days, but in dark condition, it needed 2 years of seed storage for germination. Low temperature treatment at $2^{\circ}C$ for 5 days enhanced seed germination of P. oleracea in both light and dark conditions. The maximum vagetative growth was observed at 30 to 75 days after seeding. The late seeding time such as July 1 shortened the period of vegetative growth. However, regardless of the seeding times, the first flowering was observed at about 40 days after seeding. Leaf numbers, shoot lengths, fresh and dry weights were greatly affected by the seeding dates, showing that the earlier seedings produced significantly higher shoot length, fresh and dry weight, leaf numbers and branch numbers than those of the late seedings. When all branches were removed on 68 days after seeding, their regrowth ability was 50.3% and cuttaged branches showed 78.1% regrowth as compared to intact plant.

• Horticultural Science & Technology
• /
• v.16 no.1
• /
• pp.15-17
• /
• 1998

In order to provide cool night to strawberry plant with cool air and water, an abandoned cool mine was utilized. It's effects on flower induction and fruit yield in 4 different cultivars were examined. After 70 days of transplanting, flowering frequency was below 65% and 100% in control and treatment of night cooling, respectively and regardless of cultivars. Number of flower buds and flower clusters were higher in treated plants compared with the control. Average time until flowering was much less in treated plants. In terms of yield weight and total yield, 'Suhong' was found to be the best cultivar, averaging 24.2g fruit. Cooling contributed to the 6-7 times of increase in total yield within the frame of harvesting times. The fruit were harvested at 80-97 days after transplanting.