• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.139-147
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• 2023

This study aims to select eggplant cultivars adaptive to the hot temperature period greenhouse climate by water consumption, and growth performance of plants and fruits of different European eggplant cultivars, including 'Bartok (BA)', 'Bowie (BO)', 'Black Pearl (BP)', 'Ishbilia (I)', 'Mabel (M)', 'Vestale (VE)' and 'Velia (VL)', in substrate hydroponic cultivation under hot and humid greenhouse conditions. On the 118 DAT, the leaf number and stem dry weight were highest in 'VL', followed by 'M', and there was no significant difference in leaf dry weight among cultivars. The marketable fruit number per plant was 16.4 for 'M', which was higher than other cultivars, and 'VE' and 'VL' were 8.5 and 8.8, respectively. The weight per fruit was low for 'M' at 136 g, and the highest in 'VE' and 'VL' at 332 and 281 g, respectively. There was no significant difference in fruit production per plant. In this study, 'M', which has high water use efficiency and a large number of fruits, and 'VL', which required less quantity to water consumption for producing 200 g of fruit and had a high product weight, will have excellent adaptability in the UAE greenhouse condition.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.243-251
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• 2015

This study aimed to determine the effects of root zone cooling using air duct on air temperature distribution and root zone and leaf temperatures of sweet pepper (Capsicum annum L. 'Veyron') grown on coir substrate hydroponic system in a greenhouse. When the air duct was laid at the passage adjacent the slab, the direction of air blowing was upstream at $45^{\circ}$. The cooling temperature was set at $20^{\circ}C$ for day and $18^{\circ}C$ for night. For cooing timing treatments, the cooling air was applied at all day (All-day), only night time (5 p.m. to 1 a.m.; Night), or no cooling (Control). The air temperature inside the greenhouse at a height of 40 and 80cm above the floor, and substrate and leaf temperatures, fruit characteristics, and fruit ratio were measured. Under the All-day treatment, the air temperature was decreased about $4.4{\sim}5.1^{\circ}C$ at the height of 40cm and $2.1{\sim}3.1^{\circ}C$ at the height of 80cm. Under the Night treatment, the air temperature was decreased about $3.4{\sim}3.8^{\circ}C$ at the height of 40cm and $2.2{\sim}2.7^{\circ}C$ at the height of 80cm. The daily average temperature in the substrate was in the order of the Control ($27.7^{\circ}C$) > Night ($24.1^{\circ}C$) > All-day ($22.8^{\circ}C$) treatment. Cooling the passage with either upstream blowing at $45^{\circ}$ or horizontal blowing at $180^{\circ}$ was effective in lowering the air temperature at a height of 50cm; however, no difference at a height of 100cm. Cooling the passage with perpendicular direction at $90^{\circ}$ was effective in lowering the air temperature at the height between 100 and 200cm above the floor; however, no effect on the temperature at the height of 50cm. A greater decrease in leaf temperature was found at 7 p.m. than that at 9. a.m. under both All-day and Night treatments. Fresh weight partitioning of fruit was in the order of the All-day (48.6%) > Night (45.6%) > Control (24.4%) treatment. A higher fruit production was observed under the All-day treatment, in which the accumulated average temperature was the lowest, and it may have been led to a higher proportion of photosynthate distributed to fruit than other treatments.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.149-156
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• 2014

The objective of this research was to investigate the influence of bicarbonate ($HCO_3{^-}$) concentrations in nutrient solution on the growth and physiological disorders in mother plants and occurrence of daughter plants in propagation of 'Seolhyang' strawberry (Fragaria ${\times}$ ananassa Duch.). To achieve this, the mother plants were transplanted to coir dust + perlite (7:3, v/v) medium and Hoagland solution was modified to contain 60, 90 (control), 120, 180, and $240mg{\cdot}L^{-1}$ of $HCO_3{^-}$. The symptoms of Fe, Zn and B deficiencies appeared on the mother plants in the $HCO_3{^-}$ of $240mg{\cdot}L^{-1}$ from the 60th day after treatment. The symptoms spread to all plants in the $240mg{\cdot}L^{-1}$ $HCO_3{^-}$ including daughter plants at 90 days after treatment. The$HCO_3{^-}$ concentrations higher than $120mg{\cdot}L^{-1}$ suppressed the growth of mother plants such as leaf number, chlorophyll content, fresh weight and other growth parameters. While the mother plants in $60mg{\cdot}L^{-1}$ $HCO_3{^-}$ produced 23 daughter plants, while mother plants in $240mg{\cdot}L^{-1}$ $HCO_3{^-}$ produced 13 daughter plants. The final pH 126 days after treatment in the $HCO_3{^-}$ of 60, 90, 120, 180 and $240mg{\cdot}L^{-1}$ were 5.4, 5.8, 7.3, 7.9, and 8.3, respectively. The elevation of $HCO_3{^-}$ concentrations in nutrient solution resulted in the decrease of Fe, Mn, Zn and Cu contents of above ground tissue 126 days after treatment. These results indicate that the $HCO_3{^-}$ concentrations higher than $120mg{\cdot}L^{-1}$ inhibited the growth of mother plants and occurrence of daughter plants in vegetative propagation of 'Seolhyang' strawberry.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.100-107
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• 2017

This experiment was carried out to analyze the effects of substrate reuse on the growth and yield of summer paprika in cyclic hydroponics. The test group was divided into a new coco slab, one year reused coco slab two year reused coco slab based on 30% nutrient solution reuse, and was performed from April 18 to November 31, 2016 for 30 weeks. As a result, plant height of early growth was that the 2 year reused slab was longer than the new slab but the final growth period was 56.58 cm shorter. First group flower position was that reused slab was shorter by 2.92 cm than the new slab and the second group flower position was 0.31 cm long. The relative internode length of early growth, when the reused slab was used, the imbalance in the late growth stage was increased compared with the use of the new slab. The number of growth nodes in the 1 and 2 year reused slab was the smallest with 27.4 nodes. However, the number of harvested nodes did not show the difference in the test group, and the ratio of harvested that the 2 year reused slab was the highest at 26.8%. The ratio of unmarketable fruit tended to increase as the growth progressed. Fresh weight was 227.7g for new slab, 219.2g for 2 year reused slab and 21.2g for 1 year reused slab. The dry weight of the new slab increased with the reuse of the slab. It was 17.13g for new slab, 18.26g for 1 year reused, and 19.28g for 2 year reused. The average water content of the entire growth period was smaller as the slab was reused, and the 1 year reused slab was about 20g less than the 2 year reused slab. This trend was steadily occurring throughout the entire growing season. Especially, the reused slab for 1 year was less than 60g after 3 groups compared to other test groups. In conclusion, If will control seriously occurrence of unmarketable fruits by weakening after medium growth in summer-cultivated paprika in EC-based recycling hydroponic cultivation with reused cocopeat substrate, It is not what I have to worry that decrease of the yield and deterioration of the quality due to the change of physical and chemical properties of the slab and the pathogenic bacteria infection.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.55-58
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• 2004

The objective of this study was to get information about water retention characteristics of horticultural substrates used in Korea determined by European standard method. Water retention curves were prepared at water volume (v/v, %) in relation to -10 cm, -50 cm, -100 cm water pressure head. Water retention curves showed different properties depending upon the type, the place of origin, particle size, and manufacturing processes of substrates. Peat and coir had easily available water content in the range of 30-40% and showed high water holding capacity, water buffering capacity, and aeration for plant growth. However, bark, sawdust and rice hull showed low water holding capacity about below 10%. The easily available water content of perlite and clay ball was low about 0.1-13.8%, whereas that of vermiculite and rockwool granulate was high about 25.9-52.0%. Understanding water retention characteristics of growing substrates is very important in cstablisliing optimum condition for plant growth. Further study on water retention curves for more substrates, mixture and growing media is needed.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.309-313
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• 2014

This research was conducted to establish recommendable side shoot management methods in the growth and yield of tomato in winter. A cherry tomato, $^{\circ}{\times}Unicorn^{\circ}{\pm}$ (Monsanto Korea, Korea) was cultivated in coconut coir in the form of bag as substrate. There were four treatments related to side shoot removal methods; 1) To remove all side shoots and also each one of three leaves which gives shade to each cluster attached below (UP-FL), 2) To remove all side shoots and also each one of three leaves which gives shade to each cluster only with fruit attached below (UP-FR), 3) To remove all side shoots (AS-All), and 4) To remain two leaves of each side shoot coming from right below each cluster (AS-Part). The number of malformed leaves were more in UP-FL, UP-FR, AS-All, and AS-Part in descending order, which showed the severe the removal of leaves the more the malformed leaves. The malformed leaves were diminished after the development stage the second or third cluster bloomed. The yields until fifth cluster were not different among the treatments. Therefore removal of side shoots and leaves recommends not to be done severely in early growth stage when tomato plants are cultivated in winter.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.379-387
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• 2007

This research was conducted to evaluate the influence of pre-planting fertilizer levels (PFL) and initiation time of fertigation (ITF) on growth and nutrient contents of tomato plug seedlings. The pre-planting fertilizer levels in a coir+peatmoss+perlite (4:4:2, v/v/v) substrate were adjusted to 0.5X, 1.0X and 1.0X, and initiation time of fertigation was set to 7, 14,21 and 28 days after sowing. Elevated PFL in same ITF increased plant growth such as fresh and dry weights at 35 and 70 days after sowing. Plugs with early feeding among treatments of equal amount of PFL also showed better growth as compared to those of later feeding. In each ITF, 0.5X treatment had the higher tissue $P_2O_5$ contents than 1.0X and 1.5X treatments. Elevated PFL resulted in the decrease of tissue K, Mg and Fe contents and increase of tissue Ca contents. The pH in soil solution of all root substrates except 0.5X treatment at 35 and 70 days after sowing were greater than 7.0, which is too high. This suggests that the amounts and kinds of Ca containing fertilizers should be altered to decrease the pH. The results of this research indicated that fertilizer levels should be increased to 1.5X except Ca fertilizer, and fertigation immediately after moving plug trays from germination room to greenhouse is required to increase crop growth and decrease cropping time.

• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.125-132
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• 2022

This study aimed to examine cucumber (Cucumis sativus) varieties adaptive to the desert climate by comparing and analyzing the growth, yield, and water consumption. Two long-sized cucumber varieties, 'Gulfstream' and 'Imea' and two medium-sized cucumbers, 'Nagene' and 'Sausan' were cultivated in coir substrate hydroponics under hot and humid greenhouse conditions from March 2 to June 20, 2020. On the 113 DAT, 'Nagene' had the longest plant height and the highest internode number. The marketable fruit number per plant was higher in the medium-sized varieties, which had more internode number. The marketable fruit number was 31.3 for 'Gulfstream', 30.7 for 'Imea', 57.8 for 'Nagene', or 56.0 for 'Sausan' with no significant difference in total fruit weights per plant. The water consumption required to produce 200 g of fruit was lower in the 'Nagene' (2.39 L) with the highest water use efficiency (WUE). Therefore, 'Nagene' variety may have higher adaptability to desert high temperature compared to the long-sized varieties, and it is going to be necessary to verify more medium-sized cucumber varieties.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.19-29
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• 1999

This experiment was conducted to compare with the growth and fruit quality of Citrullus lanatus cv. Mudeungsan and Citrullus vulgaris cv. Dalgona grown in fertigation and soilless culture. Seeds were sown on April 16 and transplanted on April 24, 1998. Cultural systems used in fertigation and soilless culture beds using mixed substrate, coir dust (50%) and perlite (50%). In the plot of fertigation system, the number of leaves of cv. Dalgona were increased more than that of cv Mudeungsan, but leaf area shown inversed trend. Plant growth shown greater in soilless culture than those of fertigation culture. In regardless of cultural systems, soluble solid content in fruit was higher in the cv. Dalgona than that of cv. Mudeungsan, but fruit fresh weight was greater in cv. Mudeungsan compare to the cv Dalgona. Nitrate content in petiole sap of watermelon in regardless of cultivars and cultural systems was 11.4∼13.4mg/gFW on 15 days after transplanting, and then increased to 17.1∼20.6mg/gFW on the fruit growth stage. Phosphorous content was 3.7∼5.7mg/gFW in the early growth stage while decreased to 0.6∼1.1mg/gFW from maturing stage to harvesting stage. Potassium content was increased to 5.8∼6.6mg/gFW in the early growth stage while decreased to 4.0∼4.8mg/gFW from pollination stage to harvesting stage. Calcium content in spa petiole of watermelon was higher in soilless culture as 3.4∼4.1mg/gFW than 2.5∼3.5mg/gFW of fertigation culture, but calcium content in fertigation culture during maturing stage was higher than that of soilless culture. The tendency of magnesium uptake was higher in fertigation culture than that of soilless culture, and was similarly absorbed in the range of 0.9∼1.3mg/gFW in regardless of cultural method after pollination. It was demonstrated that cv. Mudeungsan can be adapted to soilless culture and improved the fruit quality. Consequently, hydroponic possibility for year round culture in the greenhouse was recognized.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.235-243
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• 2014

This research was conducted to investigate the influence of leaching fractions (LF) in each irrigation or fertigation on plant growth and changes in chemical properties of root media during the production of seedling grafts of tomato. Two root media containing Sphagnum peat moss plus vermiculite (5:5, v/v, PV) and coir dust plus vermiculite (5:5, v/v, CV) were formulated and pre-planting fertilizers were incorporated during formulation. Then, each medium was packed into 50 cell (volume 33 cc) and 105 cell (volume 18 cc) trays and the rootstock (cv. J3B Strong) and scion (cv. Sunmyung) were grown, respectively. The seedlings were grafted at 31 days after sowing and then the cut seedling grafts (Sunmyung scion/J3B Strong rootstock) were planted into 50 cell plug trays containing each of the two root media. After induction of the graft union and new adventitious roots for 7 days, the seedling grafts were fed with fertilizer solution once a week containing 4 different N concentrations (0, 50, 100, $200mg{\cdot}L^{-1}$). When determined after 31 days from seed sowing, the highest fresh weights of the root stock seedlings were obtained with 0.75 LF in PV (8.96g/seedling) and CV (7.11g/seedling) mixes. The EC of the both mixes were 0.93 and $1.09dS{\cdot}m^{-1}$, respectively. The fresh weights of the scion seedlings 31 days after seed sowing were 4.29g with 0.50 LF in the PV and 3.13g with 0.50 LF in the CV. The root medium ECs of the two treatments were 0.76 and $1.34dS{\cdot}m^{-1}$, respectively. Fresh weights of the seedling grafts grown for 31 days were greatly influenced by post-planting fertilizer concentrations. The heavier plants were obtained in $100mg{\cdot}L^{-1}$ N treatment than any other treatments in same mixes. The substrate ECs in these two treatments were 0.98 and $1.93dS{\cdot}m^{-1}$, respectively, indicating that the desirable range of soluble salts in soil extracts is higher in the CV mix than the PV mix. Results of this study suggest that optimum EC range is different in each medium and LF need to be adjusted differently for each root medium to produce high quality seedling grafts of tomato.