• Asian Journal of Turfgrass Science
• /
• v.5 no.1
• /
• pp.23-32
• /
• 1991

The purpose of this study was to determine the vegetative growth of two cool season turfgrasses during summer season in Korea. Ten respective cultivars of Kentucky bluegrass [Poapratensis L.] and perennial ryegrass [Lolium perenne L.] were exposed to unshaded, 30% and 60% shade for 4odays. First mowing height was 7cm, and then clippings were harvested every ten days at the same height. Shading increased the total length of clippings of all cultivars of two turfgrasses, but fresh and dry weight were significantly decreased. The highest shoot length obtained at 30% shade in Kentucky bluegrass and at 60% shade in perennial ryegrass. 'Rugky', 'Sydsport', 'Wabash' and 'Baron' of Kentucky bluegrass and 'Repel', 'Omega II', 'Ovation', 'Linn', 'Bell' and 'Manhattan' of perennial ryegrass showed relatively high tolerance to shade. Especially, in 'Citation II' perennial ryegrass, fresh and dry weight were increased by 30% shade. The number of tillers generally decreased with increasing shade. In 30% shade, 'Midnight' Kentucky bluegrass and 'Omega II' perennial ryegrass were least reduced and 'Baron' Kentucky bluegrass and 'Pennant' perennial ryegrass were most reduced. The cultivars of lower growth habit in full sunlight showed shade tolerance compared to those of higher growth habit.

• The Korean Journal of Ecology
• /
• v.21 no.3
• /
• pp.179-186
• /
• 1998

Effects of lead(Pb) and calcium(Ca) on growth responses, accumulation of heavy metals and nitrogen fixation activities of Melilotus suaveolens seedlings were quantitatively analyzed during growing period. Pb contents of the root treated with 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca were 54.1, 90.9 and 26.1 folds higher than that of the control, respectively, at pH 4.2 in 28th days, and heavy metal content of plant increased with increasing of pH and Pb concentration. The melilot plant was classified as a Pb accumulator by higher accumulation of Pb in shoot than that of root. Pb treatments resulted in inhibiton of height and chlorophyll contet, and Ca treatment increased height and chlorophyll content insignificantly at pH 4.2 in 28 days. The plant biomass reduced 49, 60 and 54% at pH 4.2 and 47,53 and 50% at pH 6.5, respectively, by 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca treatment. Specific nitrogen fixation of nodules reduced 68.4% and 46.6% by 100 ppm Pb treatment and 3.7% and 24.9% by 100 ppm Pb added 100 ppm Ca at pH 4.2 and pH 6.5, respectively, so Ca inhibited significantly Pb activity and toxicity in acdic pH. Nodule formation were reduced to 33, 33 and 50% at pH 4.2 and 50, 33 and 38% at pH 6.5 by 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca, respectively.

• The Korean Journal of Ecology
• /
• v.21 no.3
• /
• pp.187-193
• /
• 1998

Seasonal changes of nitrogen fixation and growth characteristics of Melilotus suaveolens population under different light conditions were quantitatively analyzed during growting period. Height growth of M. suaveolens population was promoted after April and the shade (site 2) showed 10-20% increase of height growth in compared with that of sunny (site 1). Seasonal changes of biomass were in creased after March, the biomass at site 1 attained 78.5% that of site 2 in May. Chlorophyll content was maintained high value from March to April but, Chlorophyll content of leaf at site 1 was decreased 11.7% compared to that of site 2 in May. The nitrogen content of each organ of M. suaveolens showed higher value in March and then decreased, the high nitrogen contents of reproductive organ were achieved at the flowering stage at site 1. The root nodule of M. suaveolens population appeared in March and showed maximum value in early June and decreased remarkably after July, the amount of nodule formation of M. suaveolens at site 2 showed higher than that of site 1. The nitrogen fixation activity of root nodule of M. suaveolens initiated with shoot growth and showed maximum value in mid April, and attained second peak in early June and then decreased after July. The total nitrogen fixation of the plant showed higher value at site 2 than that of site 1. From the overall results, M. suaveolens showed increased growth under half-shady, well ventilated barren soil than fertile sunny site.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.15 no.3
• /
• pp.67-74
• /
• 2012

This study was carried out to cultivate evergreen-leaved tree container seedlings having low cost of equipment and easy to control. Two species of V. odoratissimum var. awabuki and Q. glauca planting in respective underground container were showed survival rate above 90%. The Relative growth rates of height was good in non-treatment and root collar diameter was no significant difference between treatments. The T/R ratio was respectively 1.1, 1.0 in container type of F, G. and root's biomass products was more effective than others. A container type of F showed better Quailty index than others with 16.2 values. Q. glauca was higher T/R ratio in root development than shoot and the quality index was high in container type of E, D with 4.0. 3.5, respectively. On the basis of the results obtained in this study, we can concluded that the underground container type was suitable to F in V. odoratissimum var. awabuki and to D or E in Q. glauca.

• Korean Journal of Breeding Science
• /
• v.40 no.1
• /
• pp.8-14
• /
• 2008

A complete diallel cross was performed to determine the inheritance of allelopathic potential and combining ability of six rice germplasm that showed different level of allelopathic potential against barnyardgrass. Parents and F1 of 30 crosses were assessed for allelophatic potential in field condition. Barnyardgrass (Echinochloa crus-galli (L.) Beauv. var. frumentaceae) was used for rice allelopathic potential indicator which was observed in height and shoot dry weight, then suppression percentage were calculated by comparing to barnyardgrass grown in control plot (no rice). It was found that general combining ability showed no significant effect, whereas specific combining ability and reciprocal effect were significant. Variance analysis confirmed that genetic control of allelopathic potential in rice against barnyardgrass was mostly directed by dominance gene effect. The dominant genes were associated with high allelopathic potential and recessive genes were associated with low allelopathic potential. Heritability in broad sense for barnyardgrass dry weight suppression was around 41%; whereas for barnyardgrass height suppression was 51%. However, heritability in narrow sense was very low. The finding suggests that accumulation of genes associated with allelopathic potential would be a strategy to develop promising varieties in reference with the specific combining ability of cross combinations.

• Journal of Bio-Environment Control
• /
• v.17 no.1
• /
• pp.60-65
• /
• 2008

For autumn field cutting of Sedum sarmentosum, the effects of cutting site (distal, middle, and proximal) and planting method (space drill seeding, drill seeding, and broadcast seeding) on survival rate and growth characteristics were investigated at pre- and post-winter season. Plant height root length, stem number per plant, number of branch per plant, fresh weight of shoot, and dry weight of shoot were significantly superior in distal site at pre-wintering (40 days after cutting). At post-wintering (May 10th), stem number per plant, fresh weight and dry weight per $m^2$ in cutting of distal site showed a significant increasement compared to the cutting of proximal site. At pre-wintering (40 days after cutting), the growth in space drill seeding was well than that in drill seeding and broadcast seeding, and fresh weight and dry weight per $m^2$ in space drill seeding were high in order of space drill seeding, broadcast seeding, and drill seeding. At post-wintering (May 10th), stem number per plant, fresh weight and dry weight per $m^2$ in space drill seeding were significantly increased than those in drill seeding. Accordingly, the cutting using distal site of stem in autumn field cutting was desirable for the growth and shoot yield. The space drill seeding showed the highest yield potential among three seeding methods, but broadcast seeding was favorable in saving of labor, because the fresh weight of shoot in broadcast seeding was similar in the space drill seeding at post-wintering.

• Korean Journal of Organic Agriculture
• /
• v.27 no.2
• /
• pp.205-224
• /
• 2019

This study was carried out in order to evaluate the growth promotion effects on tomato crops and to assess the mineral nutrient concentrations of farm-made liquid fertilizers used in organic cultivation in South Korea. We hope that this study will help to develop of a standardized manufacturing technique for these organic liquid fertilizers. We collected 62 farm-made liquid fertilizers made from various raw materials including fish, seaweed, food scraps, plant and crop by-products, and other materials. Two groups of tomato seedlings were treated at different times, one at 20 days and the other at 40 days after sowing. We used both foliar and soil applications. These seedlings were treated using liquid fertilizers at various dilution rates (x1000, x500 and x100). When foliar application was used, seedlings after 20 days had a 20-30% increase in shoot fresh weight with 47-48 fertilizers and seedlings after 40 days had a 20-30% increase in shoot fresh weight with 17-32 fertilizers. When soil application was used, seedlings after 20 days had the same increase in shoot fresh weight with 30-31 fertilizers and seedlings after 40 days also saw the same increase with 6-7 fertilizers. Therefore, our studies showed that application of liquid fertilizers to seedlings 20 days after sowing was most effective and that foliar treatment was more effective than soil treatments. We also observed that the higher the concentrations of fertilizer, particularly when applied twice rather than just once, the higher the rates of growth, which promoted shoot fresh weight more than plant height. Our results imply that mineral nutrients in liquid fertilizers seem to be the probable cause for the growth promotion observed in this study. However, more study is required to determine exactly which mineral nutrients are most effective.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.2
• /
• pp.192-197
• /
• 2012

The competition between green manure and forage crops frequently occurred at agricultural field because of soil fertility and livestock feeding selection. These experiments were carried out to evaluate the effects shoot and residue for green manure and forage production by leguminous crops and barley mixtures at paddy. Field experiments were conducted at paddy soil from 2008 to 2009. Treatments consisted of mixture and inter-seeding of barley and leguminous crops (hairy vetch and crimson clover). These treatments were divided into cutting height of 8 and 25 cm for using of green manure and forage at once. The residue biomass of 25 cm cutting height was higher than 8 cm and were no significantly between mixture and inter-seeding. However, residues of legume crop were significantly higher at inter-seeding than mixture. The shoot biomass of 8 cm cutting height was higher than 25 cm for forage using. The production of legume crop was high at the barley and hairy vetch seeding plot. The mixture of hairy vetch and barley showed the best biomass of shoot and residue for green manure and forage using at 25 cm of cutting height. Also this treatment could be possible to rice cultivation by no fertilization. Therefore, we suggested that 25 cm cutting of hairy vetch and barley mixture could be used for green manure and forage at the same time under rice-based cropping system.

• Horticultural Science & Technology
• /
• v.32 no.4
• /
• pp.454-462
• /
• 2014

This study was carried out to determine the effect of tree height on light transmission, spray penetration, tree growth performance, fruit quality attributes, and labor productivity in the slender-spindle system of 'Hongro'/M.9 apple trees. With increasing tree height, the light penetration into the internal parts of the canopy decreased, especially in the lower canopy. Leaf area index (LAI) increased with increasing tree height, thereby leading to a reduction in the extent of spray penetration into the interior of the canopy. With increasing tree height, shoot growth was more vigorous but produced slender shoots in the upper canopy compared to the lower canopy. Although the soluble solid content and coloration of fruit decreased, there was no difference in fruit firmness and acidity. In addition, the number of final fruit set increased, although the production of large fruit (> 305 g) decreased. The increase in tree height also significantly increased the labor required for practices such as thinning of flowers and fruits, pruning, and harvesting. Nevertheless, this problem of increased in labor input in taller trees would was eased by use of a mechanical lift. Utilizing a lift for thinning the flowers of trees 4.5 m in height saved 14.6 min per tree, compared to the use of ladder. Therefore, it is highly considerable that in order to enhance light transmission and fruit coloration, light conditions should be improved in the internal tree canopy of slender-spindle systems.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.4
• /
• pp.345-350
• /
• 2003

A series of aqueous extracts and residues from leaves, stems, roots, pods and seeds of Korean black soybean (Glycine max (L.) Merr.) were assayed against alfalfa (Medicago sativa) and barnyard grass (Echinochloa crus-galli) to determine their allelopathic activities through petri-dish and greenhouse experiments, and the results showed highest inhibition in the extracts or residues from the seeds, and followed by pods. The extracts of 40g dry tissue $\textrm{L}^{-1}$ applied on filter paper in petri-dish bioassay significantly inhibited root growth of alfalfa, and especially extracts from seeds and pods reduced root length of alfalfa more than those from leaves, stems, or roots. Plant height, root length, shoot and root dry weights of barnyard grass were reduced significantly by residue incorporation of seeds and pods as the incorporated amount increased. These results suggest that black soybean plants had herbicidal potential, and their activities were exhibited differently depending on plant parts.