• Asian Journal of Turfgrass Science
• /
• v.26 no.2
• /
• pp.116-122
• /
• 2012

The study was conducted to know whether turfgrass wear tolerance, growth, and quality could be improved by the application of silicon and potassium. First, turf responses to silicate and potassium were evaluated by several parameters such as, turf visual quality, root length, shoot density, and dry weight under the field condition. Second, turf responses to traffic frequencies were examined by turf growth (root) length, shoot density and dry weight) and soil hardness under the field condition. Finally, under traffic stress condition, the effects of silica and potassium application on wear tolerance were evaluated through the methods described above. Creeping bentgrass (Agrostis stolonifera) rooting were significantly improved by silica. The root length was enhanced by an increase in potassium silicate application. Certain level of light traffic is beneficial while frequent traffic cause serious adverse effect on visual quality of bentgrass. Under a traffic stress condition with 10 times of footing a day for 30 days, silica and potassium increased turf visual quality by 6.38% and 10.25% respectively when compared to the control. Silica and potassium treatment on trafficked plot increased turf visual quality by 11.4% and 10.2% respectively in comparison with the control with significant reduction of wear injury from the traffic. A co-application of potassium silicate with potassium sulfate provided the enhanced visual quality of turf as compared to application of silica or potassium fertilizer, respectively.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 1998.05a
• /
• pp.107-115
• /
• 1998

감자는 서늘한 기후에 알맞고 생육적온은 15-2$0^{\circ}C$로 뿌리형성의 적온은 낮 2$0^{\circ}C$, 밤14$^{\circ}C$로 고온에서는 뿌리의 수가 불어나지만 종량은 감소한다. 단위면적당 수확양을 선진국수준의 300평당(10a) 3,000kg이상으로 올리기 위해서 각종병이나 virus에 감염되지 않은 무병종서의 보급이 시급하다고 하겠다. (중략)

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10b
• /
• pp.38-39
• /
• 2003

• Korean Journal of Organic Agriculture
• /
• v.26 no.2
• /
• pp.233-243
• /
• 2018

This study was conducted to elucidate the effects of green manure crop on growth characteristics and saponin contents of Platycodin grandiflorum Ridix roots for organic farming. Rye, hairy vetch and rye+hairy vetch were cultivated as green manure crops with several different methods before transplanting P. grandiflorum Radix. In root width and number of fine-roots, when the highest scores (23.9 mm, 25.7) was recorded in rye pre-cultibated plot in $2^{nd}$ year cultivation. Fresh weight of the Platycodin grandiflorum Ridix root was no significant difference among the different green manure crop treatments, but fresh weights of the Platycodin grandiflorum Ridix root of all green manure crop treatments were higher than that of control. The total content of saponin was highest detected in Platycodin grandiflorum Ridix roots of the hairy vetch plot (1,106 mg/100 g) and rye plot (1,693 mg/100 g) in $1^{st}$ and $2^{nd}$ year cultivation, respectively. Therefore, we confirmed that precultivation of the green manure crops showed significant differences in the growth characteristics and saponin contents of the Platycodin grandiflorum Ridix root, and growth and saponin contents in the Platycodin grandiflorum Ridix root of rye precultivated plot was much higher in $2^{nd}$ year cultivation than $1^{st}$ year cultivation.

• Journal of Ginseng Research
• /
• v.2 no.1
• /
• pp.35-57
• /
• 1977

Seasenal absorption of inorganic nutrients and dry matter Production were studied with four-year-old ginseng plant. The residuary amounts of the nutrients supplied to ginseng Plantation were decreased with lime elapsed. The decreasing rate was greater in chemical plots than in Yacto Plots. The amounts of manure applied in this current year and growth in dry matter production of ginseng showed no signficant difference. The amounts of mineral nutrients per unit dry matter were proportional to the amounts of supplied with chemical fertilizer in the early period of growing season but with Yacto in the late season of growing. Seasonal changes of nitrogen, Phosphorus and Potassium contents per unit dry weight in each organ were high in the middle of May. They decreased sharply in the middle of June and then slowly decreased in both leaves and stems but gradually increased in roots. The absorption ratio of nitrogen to Phosphorus (N/P) was high, and that of nitrogen to Potassium (N/K) was few. The amounts of nitrogen, phosphorus and Potassium in leaves became lower with increasing the relative light intensity, but in stems, the concentrations were different with the kind of mineral nutrients. The requisite amounts of mineral nutrient of ginseng plant were 8.3∼9.9 kg of nitrogen, 1.2∼1.5 kg of phosphorus, 6.4∼7.9 kg of potassium Per 10 a for five years.

• Korean Journal of Weed Science
• /
• v.15 no.2
• /
• pp.131-140
• /
• 1995

This experiment was conducted to test the effect on germination and seedling growth of major industrial crops and weed control potential using alfalfa plant. When dried alfalfa residues were mixed into vermiculite, germination, length of shoot and root of crops, such as Perilla frutescens, Sorghum nevosum, Platycodon grandiflorum and weeds, Digitaria saguinalis, Setaria viridis, Siegesbechia pubescens, Ammaranthus lividus, and Solanum nigrum, were significantly inhibited as the dried residue concentration increased. More than 10% concentration of the dired residue caused 80% germination and growth inhibition. The fresh alfalfa exudation also inhibited the germination and seedling growth of crop, barley, rye, alfalfa, and sesame, and weeds, Echinochloa crus-galli, Siegesbechia viridis, and Portulaca oleracea. The degree of inhibition showed the different response according to the fresh exudation concentration, types of crops and weeds. Generally, as the exudation concentration increased, the germination and seedling growth of crops and weeds inhibited. The exudation of dried residue also exhibited the strong inhibition effect on germination and seedling growth of crops, alfalfa, Platycodon grandiflorum, barley, sesame, rye and weeds, D. sanguinalis, S. pubescens, S. viridis, P. oleracea, E. crus-galli, At the 10% concentrations, S. pubescens, and P. oleracea were not germinated and showed only 15% germination in the S. viridis. From this study, would conclude that alfalfa plant contained water soluble phytotoxic substances which were inhibitory to weeds and crops. This results suggest that alfalfa had some possibility to control some weed species using toxic compounds like natural herbicide.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.24 no.2
• /
• pp.105-114
• /
• 2004

This pot experiment was. conducted to investigate the effects of systematic variation application of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover. The treatments of systematic variation were 0/100, 25/75, 50/50, 75/25, and 100/0％ in the Fe/Cu(trial-1), Mn/Zn(trial-2), and Fe + Cu/Mn + Zn(trial-3), respectively. The treatments of Fe/Mn/Cu/Zn(trial-4) were composed of 70％ in main element and 10％ in other 3 elements, respectively. 1. In general, the unbalanced applications of Fe and Mn resulted in the Mn and Fe deficiencies(chlorosis) on white clover, respectively, because of the antagonism between Fe and Mn. In white clover, the traits of growth, root/nodule, and flowering, which were influenced by the systematic variation of Fe, Mn, Cu, and Zn, were closely correlated to each other. In the Fe/Cu trial, the 0/100 and 25/75 induced a Fe-deficiency on white clover, and the 0/100 also showed poor root growth and flowering. In addition, the 50/50 and 75/25 showed an early flowering of white clover. 2. In the Mn/Zn trial, the 0/100 induced a severe Mn-deficiency(chlorosis) on white clover. The 25/75 and 50/50, however, diminished the chlorosis symptom. The 75/25 and 100/0 showed generally good root growth and flowering of white clover. 3. In the Fe + Cu/Mn + Zn trial, the 0/100 induced a Fe-deficiency, and the 100/0 induced a Mn-deficiency on white clover, which were correlated to the poor root growth and flowering. The 75/25 showed good root growth and flowering of white clover. 1be flowering of white clover tended to be more influenced by the Fe + Cu than by the Mn + Cu ratios. 4. In the Fe/Mn/Cu/Zn trial, the Fe and Mn deficiencies on white clover, which were influenced by the Mn and Fe treatments, also occurred. The Cu and Zn-deficiency symptoms, however, were not recognized. General differences have been showed in the numbers of flowers as following orders; Zn > Cu > Mn > Fe - 70% treatments.

• Journal of Wetlands Research
• /
• v.11 no.2
• /
• pp.1-7
• /
• 2009

In order to select the water flooding-tolerant trees among Korean oaks, we cultivated the sapling of 6 deciduous oak species, Quercus acutissima, Q. mongolica, Q. variabilis, Q. dentata, Q. aliena and Q. serrata, under the water flooding treatment and the control, and analysed the growth difference among them. For comparing the growth between treatment and control, we measured 13 morphological and ecological traits, such as leaf Leaf number, leaf length, leaf width, leaf area, shoot length, stem length, stem diameter, root length, plant length, leaf weight, stem weight, root weight, plant weight. Q. serrata have no growth difference between water flooding treatment and control, but the rest 5 species showed the growth reduction in water flooding treatment. Tolerance of oak species to water flooding was risen in order of Quercus acutissima, Q. mongolica, Q. variabilis, Q. dentata, Q. aliena and Q. serrata. Thus, among Korean deciduous oaks, it is desirable to plant Q. serrata for flood plain restoration of river.

• Journal of Plant Biotechnology
• /
• v.49 no.4
• /
• pp.325-330
• /
• 2022

In this study, a plant tissue culture system was established for Atractylodes spp., an economically valuable medicinal crop in Korea that has low domestic production and is increasingly imported. In particular, Atractylodes ovata was treated with four types of cytokinins, 6-benzylaminopurine (BA), zeatin, kinetin, and thidiazuron (TDZ), in two different concentrations (0.5 and 1.0 mg/L). Among the four types of cytokinins, the BA treatment was effective for the shoot and root growth of A. ovata. Both the 0.5 mg/L and 1.0 mg/L concentrations of BA showed similar results; however, the 1.0 mg/L concentration of BA was more effective in promoting shoot and root growth. The treatments showed that the TDZ treatment was not effective for the shoot and root growth, except for the number of shoots and the fresh weight (FW) of the root; therefore, it was unsuitable for this species. In this study, we established a mass production system of A. ovata. Our results showed that direct in vitro regeneration may make a significant contribution to improving the cultivation of the medicinal plant A. ovata.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.28 no.2
• /
• pp.195-201
• /
• 1983

This study was conducted to find out the damage of rice root nematodes on rice and determine the economic injury level. In pot experiments, rice root nematode, Hirschmanniella imamuri, suppressed the growth and reduced yield of a rice, Milyang 23, above critical levels. Tillering was depressed above 5, 000 nematodes per pot inoculum levels. Heading was also delayed by 6 days when inoculum level was above 20, 000. Weight of roots and grain yield in rice plants which inoculated with 20, 000 nematodes/pot were reduced by 41% and 31%, respectively. Economic injury level of rice root nematode appeared to be 1, 500 nematodes per 30g of fresh root on Aug. 30.