• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.3
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• pp.221-226
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• 2000

Cassia mimosoides var. nomame was grown at five seeding rates (10, 20, 30, 40 and 50 kg/ha) from March 31 to September 21, 1998 at Cheju to determine influence of seeding rate on agronomic characters, and forage yield and quality. Days to flowering increased from 126 to 129 days as seeding rate increased from 10 to 50 kg/ha. The plant height increased from 86 to 99 cm as seeding rate was increased from 10 to 30 kg/hac and then decreased to 93 cm at a rate of 50 kglha. With increasing seeding rate, stem diameter quadratically decreased and the number of branches and green leaves per plant linearly decreased but the number of withering leaves per plant linearly increased. As seeding rate increased &om 10 to 30 kg/ha, fresh forage, dry matter, crude protein, and total digestible nutrients (TDN) yield increased 'from 30.7 to 49.1, 7.5 to 12.2, 0.90 to 1.57 and 4.09 to 7.09 MTha, respectively, and then decreased with further increased seeding rates. Crude protein, ether extract, nitrogen free extract, and TDN wntent increased 12.1 to 14.2% 2.2 to 2.9%, 35.1 to 39.2%, 54.8 to 60.3% respectively, but crude fiber wntent decreased 39.8 .to 33.3% and crude ash declined 4.9 to 3.8% as seeding rate increased from 10 to 50 kgiha. The optimum seeding rate to obtain the highest TDN yield was estimated to be 36kglha. (Key words : Cassia mimosoides var. nomame, Seeding rate, Forage yield, Forage quality)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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• pp.130-136
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• 2006

Growth and quality of rice are affected by various factors including the location of cultivation. This study was conducted to investigate the effects of altitudinal locations on the growth and yield-related components of rice. Nineteen Japonica type varieties were grown at Iksan (altitude, 10 m), Imsil (altitude, 150 m), Jinan (altitude, 275 m) and Jangsu (altitude, 430 m) at a similar latitude in Jeonbuk province in the south western Korea. Minimum air temperature showed a strong negative correlation with altitude. The morphological traits and yield-and quality-related components were analyzed. Longer days to heading was required at higher altitudes. However, culm length, panicle length, panicle number, grain number and rice yield were reduced at higher altitudes. Protein content of brown rice increased but fatty acid content decreased at higher altitudes. Amylose content was affected by neither the altitude nor the ecotype. Palatability of polished rice tends to be improved at higher altitudes and in early-maturing ecotypes but its relationships with altitude and ecotype were not significant. Head rice ratio was lower at higher altitudes but broken rice ratio vise versa. These results indicate that growth and quality of rice are affected significantly by changes in temperatures at the locations of different altitude. Also, the characters related to yield and quality of rice often respond incompatibly to the changes in altitudes. These results could provide valuable information for the strategic planning of rice production in geographically diverse areas.

• Journal of Ecology and Environment
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• v.36 no.3
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• pp.167-172
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• 2013

A Two-year field experiment was carried out in 2009 and 2010 to evaluate the effects of different densities of wild oat and nitrogen (N) rates on oilseed rape yield and yield components. Experimental design was split plot with three replications. Increased nitrogen rates up to 150 kg N/ha caused an increase in oilseed rape grain yield in weed-free plots (4.26 t/ha; 1t = $10^3kg$), while even at the lowest density of wild oat (15 $plants/m^2$), increasing N fertilizer only up to 50 kg/ha led to a significant increase in grain yield. Wild oat growth was favored by high levels of N. Intraspecific competition reduced biomass, 100-seed weight and number of tillers of wild oat. Both lower N rate and intraspecific competition had negative effect on wild oat growth but the weed was still able to produce a considerable number of tillers and vigorous seeds. It showed that wild oat possess a notable adaptive plasticity and can allocate a greater proportion of its resource toward reproductive organs even under resource shortage conditions and, thus, it may increase the competitive ability of the weed over the crop.Our results suggest that effective weed management should be done to prevent wild oat seed production in crops preceding oilseed rape as well as to control the weed at early season in oilseed rape fields.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.273-278
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• 2002

An efficient low-input system (LIS) for fertiliser use in rice cultivation is necessary to reduce fossil energy use and pollution. Japanese people like Japonica rice, especially cv. Koshihikari. However, it has very low lodging resistance in Japanese weather condition. Our objective was to develop a LIS with the minimum sacrifice of grain yield in rice. Koshihikari was grown using conventional fertilization as a control (CON) with 4 g N $m^{-2}$., 8g $P_2$ $O_{5}$ $m^{-2}$ and 8 g $K_2$O $m^{-2}$ as a basal fertilizer dressing. It was compared with a low fertilizer treatment (LF) with only 4 g $P_2$ $O_{5}$ $m^{-2}$ as a basal dressing in the first year and no basal phosphorus fertilizer in the second year. Chopped rice straw was incorporated into the soil before the cropping season in both years. Fertilizer of 4 g N $m^{-2}$ was top-dressed at 15 days before heading in CON plots and 30 days before heading in LF plots in both years. Lodging was significantly less in LF than in CON plots, however, no rice straw effect was found in low fertilized condition. Grain yields in LF plots were reduced by 15-16% below those of CON plots. Lower yields in LF plots were associated with a reduced number of spikelets per unit area. However, big spikelet size was acquired in LF by 10 days earlier N top dressing than CON plots. A close relationship was found between spikelet numbers and N content of the plant at heading, and between grain yield or shoot dry weight and N content of the plant at maturity. Regardless of the fertilizer application methods, N use efficiency for the number of spikelets, final total dry matter and grain yield was essentially identical among fertilizer treatments. The reduced growth and yield in the LF plots resulted from low absorption of nitrogen. Conclusively, LIS can drastically reduce chemical fertilizer use and facilitate harvest operations by reducing lodging with some yield reduction..

• Korean Journal of Organic Agriculture
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• v.6 no.1
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• pp.51-61
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• 1997

This experiment was carried out to investigate the growth response of 3 grasses to seed coating with chitosan solution and the attempt was made to estimate adequate seed coating concentrations of chitosan solution in each grass for the growth to be stimulated. Three species used in this experiment were orchardgrass, tall fescue and reed canarygrass. Six different seed coating concentrations of chitosan solution were applied as 0%(control), 0.01%, 0.05%, 0.1% and 1.0%, respectively. the results were obtained as follows; 1. Dry weight of tiller(WT), leaf area(LA), dry weight of leaf(LW), dry weight of stem(SW), dry weight of shoot(SHW), biological yield(BY) and C/F ratio were significantly different between species. 2. Number of tillers per plant(NT), dry weight of tiller(WT), dry weight of leaf(LW), dry weight of root(RW), dry weight of shoot(SHW), biological yield(BY) and T/R ration were significantly different between seed coating concentrations of chitosan solution. 3. The adequate seed coating concentrations of chitosan solution for the growth stimulating effect were different between species. The highest values of yield components and dry weight of plant parts were obtained at 1% in orchardgrass and tall fescue, and 0.05% in reed canarygrass, respectively. 4. Growth stimulating effect of seed coating in each species were different. The highest values were obtained in leaf area(LA), dry weight of leaf(LW), dry weight of root(RW), dry weight of shoot(SHW) and dry weight of biological yield(BY) in orchardgrass. The values of dry weight of stem(SW) and C/F ration were highest in reed canarygrass. 5. An increase in number of tillers per plant(NT), dry weight of leaf(LW), dry weight of stem(SW) and dry weight of root(RW) according to seed coating was attributed to the increase in dry weight of shoot(SHW). Among the aboved increasing factors, the dry weight of leaf(LW) was a main factor for the increase in dry weight of shoot(SHW). 6. An increase in dry weight of leaf(LW), dry weight of stem(SW) and dry weight of root(RW) according to seed coating was attributed to the increase in biological yield(BY). Both the dry weight of leaf(LW) and dry weight of root(RW) were main factors for the increase in biological yield(BY).

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.4
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• pp.299-306
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• 1996

This experiment was conducted from 1991 to 1993 at the forage experimental field, College of Agriculture and Life Sciences, SNU, Suweon to investigate the effects of previous crop residues on growth and yield of succeeding corn(2ea mays L.) and also to determine the best double cropping system necessary to maximize the total dry matter yield of winter forage crops plus corn for silage. In this experiment, treatments consisted of no crop as a control, late maturing Kodiak rye(Seca1e cereale L.), Bamapoli forage rape(Brassica napus Subsp. oleifera L.), G-sprinter oats(Avem sativa L.), Chief crimson clover(Trifolium incarnatum L.), Jackson Italian ryegrass(lo1ium rnultiJlorum L.), Vantage vetch(Vicia sativa L.) and early maturing Koolgrazer rye(Seca1e cereale L.). Corn leaf number and silking date were not significantly affected by previous crop residues, but the leaf number of corn following Italian ryegrass was reduced by 1.9 relative to no previous crop. The plant height and LA1 were significantly reduced during early development when corn followed Italian ryegrass and late maturing Kodiak rye (p<0.05). The dry matter and estimated TDN yields of corn were significantly reduced when corn followed Italian ryegrass and late maturing Kodiak rye. The yield reductions for corn following Italian ryegrass, late maturing Kodiak rye and early maturing Koolgrazer rye, relative to com when no previous crops were planted, were 34, 17 and 8%, respectively. Therefore, the reduction in corn growth and yield in this experiment could be explained by an allelopathic effect resulting from the Italian ryegrass and rye residues. The highest total dry matter yield of 30,509kg/ha was obtained from an early maturing rye-corn double cropping sequence in combination among the eight cropping systems.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.330-339
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• 2016

The effect of transplanting and harvest timing was evaluated for the production of high quality pigmented rice in the Yeongnam plain area. Rice was transplanted on June $2^{nd}$ and $14^{th}$ and harvested between 35 - 55 days after panicle heading at 5 - day intervals. Three black- and 3 red-pigmented rice cultivars (such as early cultivar : Josengheugchal, Jeogjinju; medium cultivar : Heugseol, Hongjinju; and mid-late cultivar : Sintoheugmi, Geongganghongmi) were studied. Yield components like spikelet number, ripened grain ratio, and 1,000 - grain weight of the black- and red-pigmented rice cultivars were similar for both the June 2 and June 14 transplantings but panicle number per $m^2$ was higher for the June 14 transplanting than for June 2. This contributed to a higher brown rice yield for the June 14 transplanting, by 6 - 19% for black-pigmented rice, and by 10 - 21% for red-pigmented rice than the yield for the June 2 transplanting. Total anthocyanin and polyphenol productions of the pigmented rice were also higher in the June 14 transplanting than that in the June 2 transplanting due to high brown rice yield. Based on the combined pigmented brown rice yield, we concluded that the optimal harvest timing would be 40 - 45 days after panicle heading (DAH) for the black-pigmented rice and 45 - 50 DAH for the red-pigmented rice. This study suggests that optimum transplanting and harvest timings play an important role for production of high quality pigmented rice in the Yeongnam plain area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.287-293
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• 1987

To find out the effects of seed maturity and seeding rate of two planting times on the seed emergence and silage and seed yields of rye, a local variety 'Paldanghomir' harvested 30 and 45 days after heading(DAH) were planted at five seeding rates on October(optimum) and November(late) in 1985. At the optimum planting, number of seedlings per unit area and number of tillers per plant were affected by seeding rate, but not by the seed maturities. However, at the late planting, number of seedlings per unit area and number of tillers per plant wer higher in the seed harvested 45 DAH, and they were not correlated with seeding rate in both seeds harvested 30 and 45 DAH. Heading date was 2 or 3 days earlier in the seeds harvested 45 DAH in both planting times. Silage yield was higher at the optimum planting and increased as seeding rate increased in both planting times. Number of spike and 1000~seed weight were higher at the optimum planting than late planting and higher in the seed harvested 45 DAH than 30 DAH in late planting, but were not different among seeding rates. Seed yield at optimum planting showed no difference between seed maturities and among seeding rates, and recommandable seeding rate was 600 seeds per $m^2$. At late planting the seed yield of the seed harvested 45 DAH in the seeding rate over 750 seeds per $m^2$ approached to the yield of the optimum planting. The seed harvested 30 DAH was unstable because of extremely low emergence rate and yield even at the higher seeding rate in late planting. planting.

• Korean Journal of Organic Agriculture
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• v.28 no.2
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• pp.209-221
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• 2020

Highbush blueberries (Vaccinium corymbosum), 'Duke', 'Bluecrop', and 'Elliott', were applied with ground cover mulch systems to evaluate bush growth and fruit characteristics. Soil temperature variation was lower in the woodchip mulching plot. Therefore, CEC, soil pH, phosphate, mineral ions were not significantly different among mulching materials. The number of main stem was higher in woodchip > sawdust > rice husk > plastic film mulching plot, respectively. Total shoot number was also higher in organic mulching plots than in plastic film plot. However, total shoot number was not significantly different among the organic mulching plots. Fruit weight was the highest in the woodchip mulching plot of all blueberry cultivars, however, soluble sugar content, organic acidity, fruit firmness were not significantly different in mulching materials. Yield was higher in organic mulching plots than in plastic film plot in all blueberry cultivars. Especially, yield per shrub of woodchip plots was the highest about 3.6 kg in 'Duke', 2.7 kg in 'Bluecrop', and 2.6 kg in 'Elliott'. Furthermore, correlation of main stem number and yield was highly significant (r² = 0.8413). Therefore, woodchip mulching is expected to be an eco-friendly method to increase the number of stems and the yield of blueberries.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.45-51
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• 1987

This experiment was conducted to find out the critical competitive period and competitive ability of rice against red rice. Plant height and number of tillers of rice decreased as red rice competed with rice during active tillering stage. The maximum tillering stage of rice competed with red rice became about 10days earlier than those non-competed. Significant yield reduction of rice was observed in the plots competed for 20 days after transplating or longer. Such a yield reduction can be mainly attributed to the decrease in number of panicles per hill and grain number per panicle. In a replacement diagram for rice and red rice, their competition is turned out being antagonized. The relative yield total was considered lower than 1. Grain number, culm and panicle length of rice was not affected significantly by inter-specific competition. Rice grain yield reduction was highly correlated with the number of panicles of red rice. Three hundred panicles/$m^2$ of the red rice were necessary to reduce rice grain yield by 50% of the check plot.