• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.167-173
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• 2014

This research was conducted to establish appropriate methods to prune tomato side stems during summer. Cherry tomatoes "Unicorn" (Monsanto Korea, Korea) were grown in the coir based growing medium, and irrigation was controlled time based system. There were three pruning treatments: 1) removing all side stems (ACUT), 2) remaining two leaves on the side stems right below any cluster (PCUT), and 3) remaining two leaves on all side stems (LEFT). Experimental results showed that the occurrence of swollen stems, a symptom of nutrient excess, was influenced by side stem pruning due to blocking of consumption of photosynthetic products. The photosynthetic rate was not different between leaves on main stem and those on side shoots. Therefore the differences in the total amounts of photosynthetic products seemed to come out from the differences in leaf areas on each treatments, influencing on fruit yield difference. The yields and harvesting rates were better in ACUT treatment when tomato plants were harvested until $5^{th}$ cluster, however tomato yield was higher in LEFT treatment when more then $5^{th}$ clusters were harvested.

• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.175-180
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• 1992

Cherry tomatoes(Lycopersicon esculentum) were grown in circulating deep flow hydroponic system. The pH of the nutrient solution was increased and the EC was decreased with time. The clusters of ‘Mini Carol’ were branched severely, whereas those of ‘Chelsea Mini’ and ‘Popo’ were a little branched or not. The vegetative growth was similar between cultivars. But the yield of fruits was by far the largest in ‘Mini Carol’ compared to other cultivars, and not different between ‘Chelsea Mini’ and ‘Popo’. Internal qualities of fruits, like as sugar, sugar/organic acid, and vitamin C, are good in ‘Mini Carol’. As the result of panel test, ‘Mini Carol’ is good for softness, easeness of eating, toughness of skin and so on, so it is believed that ‘Mini Carol’ is the most acceptable to consumers in hydroponic culture.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.456-463
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• 2020

This research was conducted to examine the changes in yield and difference in growth, using rootstocks in tomatoes as the growth indicators. Seedlings of tomato 'Gama', were used as scion and non-grafted control, while 4 different grafted tomatoes 'Powerguard', 'T1', 'L1', and 'B.blocking' were used as rootstocks. The non-grafted and grafted plants were grown in hydroponics for long-duration cultivation under plastic greenhouse conditions. The total yield of grafted tomato 'Powerguard' and non-grafted tomato 'Gama' were 8,428 g and 7,645 g, respectively. The flowering position of grafted plants 'B.blocking' and non-grafted plants at the latter period were 17.58 cm and 14.92 cm, respectively. The results showed that the yield and the balance of the plant were improved until the end of the harvest by grafting. The difference in yield between non-grafted and grafted tomatoes was evident in the 19th cluster, 236 days after planting. Therefore using rootstocks could be advantageous for long-duration cultivation in tomatoes.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.783-789
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• 2010

The effective method for heating root-zone during winter season was studied in the aspects of growth, yield and economics for tomato ($Solanum$ $lycopersicum$) in perlite bag culture. There were four root-zone heating treatments: two hours heating from one hour before to one hour after sunrise, four hours from two hours before to two hours after sunrise, 15 hours after sunset, and no heating. The growth characteristics of the upper parts of plants were not significantly different among the treatments, but root volume increased with longer heating of the root zone. The Plant Development Index, using stem diameter and the length between growing tip and the upper flowering truss, showed relation between yield per cluster and growth pattern. The treatment heating for four hours was the most economic in terms of growth and yield of tomato.

• Journal of Bio-Environment Control
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• v.28 no.1
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• pp.46-54
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• 2019

Experiments of local cooling and heating on crown and root zone of forcing cultivation of strawberry 'Seolhyang' using heat pump and root pruning before planting were conducted. During the daytime, the crown surface temperature of the crown local cooling treatment was maintained at $18{\sim}22^{\circ}C$. This is suitable for flower differentiation, while those of control and root zone local cooling treatment were above $30^{\circ}C$. Budding rate of first flower clusters and initial yields were in the order of crown local cooling, root zone local cooling and control in root pruning plantlet and non pruning plantlet, except for purchase plantlet. Those of root pruning plantlet were higher than those of non pruning plantlet. These trends were evident in the yield of the first flower cluster until February 14, 2018, and the effect of local cooling and root pruning decreased from March 9, 2018. The budding rates of the second flower cluster according to the local cooling and root pruning treatments were not noticeable compared to first flower cluster but showed the same tendency as that of first flower cluster. In the heating experiment, root zone local heating(root zone $20^{\circ}C$+inside greenhouse $5^{\circ}C$) and crown local heating(crown $20^{\circ}C$+inside greenhouse $5^{\circ}C$) saved 59% and 65% of heating fuel, respectively, compared to control(inside greenhouse $9^{\circ}C$). Considering the electric power consumption according to the heat pump operation, the heating costs were reduced by 55% and 61%, respectively.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.217-225
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• 2015

Local heating system providing hot air locally to growing parts including shoot apex and flower cluster which were temperature-sensitive organs of cherry tomato was developed to reduce energy consumption for greenhouse heating without decline of crop growth. Growing part following local heating system was composed of double duct distributer which connected inner and outer ducts with hot air heater and winder which moved ducts up and down following growing parts with plant growth. Growing part local heating system was compared with conventional bottom duct heating system with respect to distributions of air and leaf surface temperatures according to height, growth characteristics and energy consumption. By growing part local heating, air temperature around growing part was maintained $0.9{\sim}2.0^{\circ}C$ higher than that of lower part of crop and leaf surface temperature was also stratified according to height. Investigations on crop growth characteristics and crop yield showed no statistically significant difference except for plant height between bottom duct heating and growing part local heating. As a result, the growing part local heating system consumed 23.7% less heating energy than the bottom duct heating system without decrease of crop yield.