• Journal of Practical Agriculture & Fisheries Research
• /
• v.21 no.2
• /
• pp.59-69
• /
• 2019

This study was carried out to investigate effects of soil water content on growth and antioxidative enzymes activity of tomato seedlings during the nursery period. The water stress significantly damages morphological, physiological, and biochemical activities in plants. The seedlings planted with soil on the tray were irrigated and categorized into 3 groups with 30 g, 40 g, and 50 g of plant-soil weight. After then, the changes in weight of the soil and the seedling were measured evey 2 hours for 4 days and the leaf temperature was measured with the thermal-camera at the same time. The antioxidant enzymes were measured to determine the level of stress using all of the seedling samples. The result showed that the decrease of soil weight in the day time was faster than that in the night time, but there was no significant difference in the weight loss of the seedlings and soil among the groups. However, the group with 50 g of wight showed the highest SOD and POD contents. This is considered that the continuously wet soil on the root zone of the seedlings caused more stress for the seedlings. Therefore, it is concluded that the excess moisture content causes stress to stimulate the secretion of antioxidant enzymes, and the effect of stress is required to be analyzed comprehensively using environmental data and also the physiological data that are collected over a longer period.

• Journal of Bio-Environment Control
• /
• v.15 no.2
• /
• pp.156-161
• /
• 2006

Overhead and sub-irrigation of deep sea water to tomato seedlings reduced the height as 50% and 58% than control plants. In the same treatment with surface sea water and NaCl water, the reduced rate in tomato seedlings' height were 49% and 56% in overhead irrigation, and 47% and 57% in sub-irrigation, respectively. Most effective method for the inhibition of the growth of the seedling was sub-irrigation method, which supplied water through the roots. No significant difference was observed on fresh weight of the upper part of tomato and cucumber seedlings, though the sub-irrigation reduced the fresh weight than the overhead irrigation. The reduced rate of fresh weight of seedlings by overhead irrigation was by 38% and sub-irrigation by 49% as compared to control. Similarly dry weight of upper and under soil parts of seedlings showed same trend of results thereof as fresh weight. This result can be traced to reduction of growth caused by salts in the water. In stem diameter of seedlings no significant difference was observed between two irrigation methods, even though both deep sea and NaCl water reduced stem diameter, as compared to control water. Overhead irrigation can be chosen by seedling producers because of better seedling quality by using TH ratio. Seedling compactness were not noticed in both the overhead and sub-irrigation. Sub-irrigation was found more effective method far the inhibition of height and compactness of tomato seedlings. Higher the concentration of NaCl, deep sea, and surface sea water, lesser the growth in height, fresh and dry weight, stem diameter, and leaf area was obtained. No significant difference was found, though sub-irrigation suppress the growth of seedlings.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.2 no.1
• /
• pp.65-73
• /
• 1994

Earthworm cast was investigated in this study in order to domestically develop inexpensive and safe plug nursery soil. 20,30,40 and 50% of earthworm cast were added to the nursery soil as vegetable plant growth media, in which peatmoss and vermiculite constituted the rest of the soil. The effects of earthworm cast on the growth of pepper (Capsicum annuum L.) seedling were obtained as follows. 1. According to the growth stages, significant differences(p=0.001) were recorded in number of leaves, leaf area and biological dry matter yield per plant(shoor or root dry matter yield per plant). In view of mixing ratios in the nursery soil, number of leaves, leaf area and stem weight per plant showed differences significantly at 1% level and leaf weight, root weight and biological dry weight per plant at 5% level, respectively. 2. The nursery soil with earthworm cast showed increased number of leaves and leaf area per plant compared to the commercial nursery soil particularly in the later stage of this study than in the earlier stage 3. Through the total period of seedling growth, leaf weight, stem weight and root weight per plant in the nursery soil with earthworm cast were genrally higher than those in the control and this trend was apparant in the treatment of more than 40% of mixing ratio with earthworm cast. 4. Although leaf weight per plant was higher than stem weight per plant till the 3rd week, from the 4th week stem weight per plant was getting higher. In the later stage of seedling growth, the stem weight was higher in the earthworm cast mixed treatment than that in the control. 5. There was no significant difference on biological dry matter yield in the earlier stage of this study, however in the later stage, it was higher in the earthworm cast mixed treatment than that in the control.

• Journal of Bio-Environment Control
• /
• v.16 no.3
• /
• pp.205-209
• /
• 2007

This experiment was conducted to investigate the growth of plug seedlings and yield of tomato affected by the concentration of triazole and the treatment time. The length and leaf area of tomato seed-lings were reduced by the application of triazole compared to control. Growth reduction of seedlings was greater by earlier application and higher concentration of triazole. The growth of tomato treated with hexaconazole were similar with control 4 weeks after sowing. The triazole treatment lowered the height of the first fruit set compared to control. However, triazole treatment did not affect the number of fruits and yield.

• Journal of Bio-Environment Control
• /
• v.12 no.1
• /
• pp.22-25
• /
• 2003

Seedlings of ‘Nokgwang’ and ‘Kwari’ green pepper were cultured in 32-cell plug trays in TK$_2$ medium to find out optimal concentrations of phosphate. Seedling growth of both ‘Nokgwang’ and ‘Kwari’ cultivars was affected by phosphate strength. Applying P fertilizer to the plug system caused a marked increase in plant height and leaf area at 1.0 phosphate strength. On the other hand, total dry weight increased with increasing phosphate strength. Higher chlorophyll content was observed in ‘Nokgwang’ than ‘Kwari’ in all treatments. Phosphate strength greater than 0.5 gave similar chlorophyll content. Photosynthetic rate was higher for plants fertilized with 1.0 strength for ‘Nokgwang’ and 0.5 strength for ‘Kwari’than the other treatments. Higher concentrations of phosphate reduced photosynthesis in both cultivars. With ‘Nokgwang’increasing concentration of phosphate up to 1.0 strength resulted in increase in stomatal conductance and transpiration rate.

• Journal of Bio-Environment Control
• /
• v.29 no.4
• /
• pp.399-405
• /
• 2020

Recently, it is difficult to produce uniform scions and rootstocks with high quality in a greenhouse due to weather extremes. The closed transplant production system is useful for producing scions and rootstocks with desirable morphological characteristics by environment control regardless of weather outside. In this study, we investigated transpiration rates and growth of cucumber and tomato scions and rootstocks grown under different light intensity conditions for precise irrigation control in a closed transplant production system. Hanging system to measure continuously the weight of plug tray consisting of seedlings and substrate with load-cell was installed in each growing bed. Using this system, we confirmed initial wilting point of cucumber and tomato seedlings, and conducted subirrigation when moisture content of substrate was not below 50%. The irrigation time of cucumber scions and rootstocks were 7 and 6 days after sowing, respectively. In tomato scions and rootstocks grown under PPF (photosynthetic photon flux) 300 μmol·m^-2·s^-1, the irrigation time were 5, 8, 11, and 13 days after sowing. Increasing light intensity increased transpiration rates and differences of transpiration rates by light intensity was higher in tomato seedlings. The growth of cucumber and tomato seedlings was promoted by increasing light intensity, especially, hypocotyl elongation and stem thickening was affected by light intensity. Cumulative transpiration rate of plug tray in cucumber and tomato seedlings was increased by increasing light intensity, and daily transpiration rate per seedling was regressed by 1st-order linear equation with high correlation coefficient. Estimation of transpiration rates by weighing continuously plug tray of vegetable seedlings can be useful to control more accurately irrigation schedule in a closed transplant production system.

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

• Journal of Bio-Environment Control
• /
• v.12 no.3
• /
• pp.166-172
• /
• 2003

Rockwool slabs used for hydroponic cultures are expected to have potential to be reused after breakdown as a growing medium component for hydroponic culture of vegetables and cut flowers, pot plants, or plug plants. This study was conducted to test the feasibility of using particles of used rockwool slabs (PURS) mixed with woodchips for growing plug seedlings of ‘Nokkufang’ pepper. In the first experiment growth of pepper seedlings was tested in media of steam sterilized PURS mixed with chestnut woodchips (CW), which was weatherized for six months and screened through 2.8 mm or 5.6 mm sieves, at 100:0, 75:25, 50:50, 28:75 or 0:100 (%, v/v). In the second experiment growth of pepper seedlings was tested in 20 different media containing steam sterilized PURS mixed with 4 mm chestnut woodchips (CW), 4 mm pinc woodchips (PW), coir, peatmoss, or perlite. In the first experiment, there were no significant growth differences as affectcd by particle size of CW, while the overall best growth was achieved il1 the control and l00% PURS. In the second experiment, seedling growth was enhanced as compared to the control in 100% PURS or PURS mixed with peatmoss, coir, or perlite. In contrast, growth was suppressed as the proportion of peatmoss or coir mixed with PURS decreased and the proportion of CW increased. Growth was better in the PURS + peatmoss than in the 100% PURS or PURS + coir, and when woodchips were mixed with coir than peatmoss.

• Journal of Bio-Environment Control
• /
• v.18 no.1
• /
• pp.51-59
• /
• 2009

Bulb onion cultivation area has been restricted in southern part of Korea to avoid blotting and bulb division. The traditional culture method is transplanting bare-rooted plantlet into the field at the end of summer and harvesting at the beginning of next summer. The hot weather and weak plantlets occasionally causes unstable supply of onions in autumn. In order to enlarge cultivation area and to reduce culture period, long nursery system using plug tray and spring transplanting was tried. Forty cultivars collected from Korea and Japan were nursed using 200-plug tray and transplanted to the field in spring. Marketable yield was not related to the seedling size but lodging time. Cultivar of 'Hamasodachi' was lodged early and resulted low marketable yield. Cultivar of 'Cheonjudaego' was not lodged and yielded high but not in accordance with storability. Generally early lodged cultivars showed low storability. In order to avoid rainy harvesting season, cultivars requires excessive long time for lodging is not recommended for spring culture. Using plug nursery and spring transplanting, we successfully produced marketable onions in 3 months. But immediate using of the harvested onion is recommended. The storability of produced onions showed different result among cultivars, storage of spring onion was not recommended.

• Horticultural Science & Technology
• /
• v.18 no.1
• /
• pp.33-38
• /
• 2000

This study was conducted in an effort to meet the need for domestic production of hydroponic media and for medium development using recycled hydroponic rockwool slabs. Two experiments were conducted to evaluate the growth of plug seedlings of petunia 'Romeo' in various mixtures including particles of used rockwool slabs (rockwool particles) and wood chips. In the first experiment, seedlings were grown in plugs filled with mixtures of steam- sterilized rockwool particles and chestnut wood chips, which had been weathered for six months and screened through either 2.8 mm or 5.6 mm sieve, at the mixing ratio of 100:0, 75:25, 50:50, 25:75, or 0:100 (v/v). In the second experiment, seedlings were grown in plugs filled with twenty different mixtures of steam-sterilized particles of used hydroponic rockwool slabs with 4 mm chestnut or pine wood chips, coir, peatmoss, or perlite. In the first experiment seedling growth was not affected by particle size of chestnut wood chips, was superior in the control (commercial plug medium) and in 100% rockwool particles, but was suppressed as mixing ratio of chestnut wood chips increased. In the second experiment, leaf length, and shoot fresh and dry weights were the greatest in rockwool particles+peatmoss+coir treatment, followed by rockwool particles+peatmoss treatment. Leaf length was suppressed as ratio of wood chips increased, especially of chestnut wood chips. Root development was the greatest in rockwool particles+peatmoss+perlite treatment, followed by the control, and rockwool particles+peatmoss+coir treatment. The growth was suppressed as the mixing ratio of rockwool particles, peatmoss, or coir decreased.