• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.134-142
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• 1991

Since IR8, the first high-yielding rice cultivar characterised by semidwarf and high-tillering, was released in 1966, rice yields during the last two decades have apparently reached a plateau and subsequent efforts to further improve yielding ability have not resulted in visible gains. At this point of time, a new ideotype of rice plant would be necessary to increase grain yield potential. This experiment was conducted to investigate the yield contribution of different tillers within a plant in relation to an ideo type of rice plant. A low-tillering, large panicled IR25588 was compared with a high-tillering, small panicled IR58. Based on spikelet number and grain weight per panicle, the top six panicles in both low- and high-tillering cultivarswere significantly bigger than those in the other panicles. The top six panicles were M, PI, P2, P3, P4 and S1P2 in both cultivars. Their tillers had 100% probability of occurring. The top six tillers were characterised by earlier initiation and heading, longer growth duration, greater leaf area. and heavier culm and total dry weight per tiller. The top six panicles, based on grain weight was mainly due to higher spikelet number per panicle with little differences in 1,000 grain weight and percent fertility. They had also a greater number of high -density grains. The top six panicles were significantly bigger than the rest of the panicles in both low- and high-tilliering types suggesting that a new rice ideotype having six or fewer potential tillers or panicles per paint with 200 to 250 spikelets per panicle (a low-tillering, paicle weight type) may help increase grain yield potential since they have been shown to be superior physio-morphologically to the rest of the tillers.

• Korean Journal of Weed Science
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• v.9 no.1
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• pp.1-15
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• 1989

The seventeen barnyardgrass [Echinochloa crus-galli (L.) Beauv.] accessions, which were collected national-widely in 1986 and selected two times through 1987, were experimented at 1988. To identify the ecological properties of the collected accessions of native barnyardgrass species as a weed, the experiment was conducted with Wagner pots in size of I/500a and under PE film house. 1. Accessions were classified into 5 specific groups in plant type properties by use of data from plant height, number of maximum tillers, erectness, culm length and panicle type, among others. 2. As for species identification, they were clustered into 3 similar groups and 2 individual species by use of data from color, first-glumer type, and erectness. 3. Four groups were identified for elongational properties by plant height of 22 days old seedling, length of culm, panical, leaf length and width, and inter-node and spikelet, among others. 4. Properties on quanititative growth were classified into 4 groups and 1 individual accession corresponding to differential plant height of 22 days old seedling, length of culm, panical, inter-node, leaf-sheath, spikelet, first-glumes length, grain, number of tillers, spike, and grain weight. 5. Due to different daily increasing rate in seedling height, dry weight, number of tillers and ratio in dry weight to plant height, the growth rate properties were clustered into 4 groups and one individual accession. 6. Properties on seedling growth were classified into 4 groups by use of differential date in length and width of first-leaf, plant height, number of tillers, and dry weight of young and medium aged seedling. 7. Responding to heading date, the accessions were classified into 3 groups : temperative sensitive, medium, and short-day length sensitive types, respectively. 8. By integrating of all quanititative and attributable characters, the seventeen accessions were clustered into 4 groups and 2 individual accessions.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.194-199
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• 2011

This study was conducted to evaluate fertigation effects of pig slurry (PS) and chemical fertilizer (CF) in cucumber by investigating the growth and yield, nutrient content and uptake, nutrient use efficiency, and soil characteristics in greenhouse cultivation. The cropping patterns of cucumber were semi-forcing culture and retarding culture, and the experiment involves four treatments: No fertilizer (NF), $26mg\;L^{-1}$ and $52mg\;L^{-1}$ of N application by slurry composting biofiltration liquefied fertilizer (SCBLF), and $52mg\;L^{-1}$ of N treatment by chemical fertilizer. The difference on the plant height of cucumber between SCBLF and CF treatments was no significant, but fresh weight and dry weight of stem and root were higher in $26mg\;L^{-1}$ SCBLF treatment. The Ca content of the leaf was lower in the treatments of SCBLF and the K content of the root was lower in the $52mg\;L^{-1}$ CF treatment. The Ca content of the stem was lowest in the $52mg\;L^{-1}$ CF treatment and the mineral content of the fruit showed no significant difference. In case of semi-forcing culture, the gross yield was lower in the $52mg\;L^{-1}$ CF treatment and the yield of unmarketable fruit was lower in the SCBLF treatments. The nutrient use efficiency of cucumber is as follows: K (8.3 ~ 30.9%), N (4.2 ~ 13.0%), P (1.9 ~ 2.0%). The SCBLF treatments showed higher figure in the soil pH than that of the CF treatment, while EC and the content of $NO_3$-N were higher in the CF treatment than the former. The content of exchangeable K was higher in the plot treated with $52mg\;L^{-1}$ SCBLF, and there were no significant differences in the content of Ca and Mg between the treatments. In conclusion, it is suggested that the application of liquefied manure made from pig slurry may be able to replace the use of chemical fertilizer in nitrogen and potassium.

• Korean Journal of Organic Agriculture
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• v.16 no.4
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• pp.435-453
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• 2008

The crop rotation is very important in the organic agriculture and the soybean crop should be included in the rotation. Even though the inoculation of the root can be performed by the soil inoculation in the soybean crop, the effect of the soil inoculation should be proved in the organic soil. For the research of the effects in the formation of the nodule of soybeans, the growth and the quantity through the inoculation into the soil, the field experiment was conducted in 2006 at Ipjang Experimental Farm of Dankook University. The number of nodule in the testing varieties of the inoculated soil plot was $1.4{\sim}2$ times larger than those in the non-inoculated soil plot. The number of nodule was decreased in the non-inoculated soil plot after R2 stage, but it was increased in the inoculated before R4 stage and it was decreased after then. The periodical change of weight of the nodule was shown as same as the number of nodule. The dry weight of inoculated was increased than non-inoculated in Daewonkong, but it was decreased than non-inoculated in Shinpaldalkong2 and SS2-2. The amount of chlorophyll of the inoculated soil plot was more than the non-inoculated soil plot by 9% in Daewonkong, but the inoculated soil plot was less than the non-inoculated soil plot by 13%, 33% each in Shinpaldalkong2 and SS2-2. The number of pods, the number of grains and the weight of grains in the yield characteristics of the inoculated soil plot were more than in the non-inoculated soil plot in Daewonkong, but the number of pods, grains and the weight of grains in the yield result in the inoculated soil plot was less than in the non-inoculated soil plot in Shinpaldalkong2 and SS2-2. The mean yield(per 10a) of Daewonkong was increased 11% in the inoculated soil plot, but the mean yeil(per 10a) of Shinpaldalkong2 was decreased 4% and SS2-2 was also decreased 23%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.204-212
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• 2019

The optimal application rate of a controlled release fertilizer (CRF) on the growth, yield, and seeding time of rice grown on seedling trays was investigated. The experimental field was located at $37^{\circ}22^{\prime}10^{{\prime}{\prime}}N$ latitude and $127^{\circ}03^{\prime}85^{{\prime}{\prime}}E$ longitude in Hwaseong, Gyeonggi-do, Republic of Korea. The soil in the paddy field was a clay loam. The CRF used in the experiment contained $300g\;kg^{-1}$ of nitrogen, $60g\;kg^{-1}$ of phosphate, and $60g\;kg^{-1}$ of potassium, respectively. The CRF was applied at the rate of 0, 200, 300, 400, 500, and 600 grams on rice seedling tray compared with the field application based on soil testing (control), respectively. The CRF can be applied as single application(which can replace basal fertilizer application and two top dressing application) directly to the seedling tray, and showed the minimum release at the seedling period. Considering the plant growth, nitrogen use efficency and yield of rice, the optimal application rate of developed CRF was 500 g per seedling tray and the yield of rice at this application rate was $4.92{\sim}5.04Mg\;ha^{-1}$. The regression formula between the rice yield and application rates of CRF was as follows ; "$Y=0.0002{\chi}^2+0.0963{\chi}+411.6$($R^2$ : 0.9922) in 2010 and $Y=8E-6{\chi}^2+0.2723{\chi}+344.04$($R^2$:0.9864) in 2011, Y : Rice yield ($Mg\;ha^{-1}$), ${\chi}$ : Application rate (grams) of controlled release fertilizer". The optimum application rates of CRF per rice seedling tray by regression formula was 498 grams in 2010 and 513 grams in 2011.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.447-453
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• 2019

In this study, the effect of supplying volume and frequency of a nutrient solution consisted with $NO_3-N$ 4.6, $NH_4-N$ 3.4, $PO_4-P$ 3, K 3, Ca 4.6 and Mg $2.2mmol{\cdot}L^{-1}$ on growth and fruit quality of 'Duke' blueberry was investigated. Three years old 'Duke' blueberry bushes cultivated in containers ($60{\times}80{\times}40cm$) filled with 130L peat moss and 40L pearlite (v/v) were selected for the experiment. The growth containers were mulched with sawdust. Two different volumes (4L and 8L) of nutrient solution was tested at three different supplying frequencies (one time, two times, and three times) per week and the drainage quality of nutrient solution and fruit quality of 'Duke' blueberry was evaluated. The optimal drainage rate for the vegetable cultivation is known to be 20-30%. The results revealed that the average drainage rates of 27% and 29% for the nutrient solution supplied in 'Duke' blueberry growth medium at 4L, 2 times/7 days and 4L, 3 times/7days, respectively. The highest shoot diameter (4.2mm) and shoot length (31cm) of 'Duke' blueberry was recorded with the 8L of nutrient solution supplied at 3 times per 7 days. According to the analysis of inorganic components in the drainage of nutrient solution, there was a tendency of absorbing nitrogen at the early stage of growth. The supplying volume and frequency of nutrient solution was not significantly affected on 'Duke' blueberry fruit weight, soluble solids content, and titratable acidity. The highest yield per bush (2.7kg) was recorded for the nutrient solution supplied with 4L at three times per 7 days, while the 4L nutrient solution supplied at one time per 7 days resulted the lowest yield of 1.4kg per bush. Consequently, the tested nutrient solution can be applied for the 'Duke' blueberry bushes with the volume of 4L at three times per week for the better crop growth.

• Research in Plant Disease
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• v.25 no.3
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• pp.114-123
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• 2019

QD LED has an ideal light source for growing crops and can also be used to control plant pathogenic microorganisms. The mycelial growth inhibition effect of QD LED light on Rhizoctonia solani, Phytophthora drechsleri, Sclerotinia sclerotiorum, Sclerotinia minor, Botrytis cinerea, Fusarium oxysporum, Pectobacterium carotovorum, and Xanthomonas campestris were investigated. According to the results, BLUE (450 nm) light, suppressed S. sclerotiorum by 16.7% at 50 cm height from the light source, and 94.1% mycelial growth at 30 cm height. Mycelial growth of Sclerotinia minor was inhibited by 80.4% at 50 cm height and 36.3% at 50 cm height in B. cinerea. S. minor, and B. cinerea was inhibited by 100% mycelial growth at a height of 30 cm from the light source. At 15 cm height, all three pathogens (B. cinerea, S. minor, and S. sclerotiorum) was inhibited by 100%. QD RED (M1) and QD RED (M2) light suppressed mycelial growth of S. minor and B. cinerea by 100% at 30 cm and 15 cm height from the light source. For S. sclerotiorum, QD RED (M1) and QD RED (M2) showed 75.2% and 100% inhibition, respectively. Further experiment was conducted to know the suppression effect of lights after inoculating the fungal pathogens on lettuce crop. According to the results, QD RED (M2) suppressed the S. sclerotiorum by 59.9%. In addition, Blue (450 nm), QD RED (M1), and QD RED (M2) light reduce the infestation by 59.9%. In case of B. cinerea, disease reduction was found 84% by BLUE (450 nm) light. Results suggest that the growth inhibition of mycelium increases by Quantum dot LED light.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.2
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• pp.110-118
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• 2021

This study was conducted to investigate the effects of species and varieties of summer forage crops on growth characteristics and productivity in Sihwa reclaimed land. The summer forage crops used in the trial were silage corn, sorghum×sudangrass hybrid(SSH), and proso millet. For each forage species, Gwangpyeongok(GPO), P15453, P1952 and P2088 were used for silage corn, and 877F, Green star, Honey chew, and Turbo gold cultivars were used for SSH. For proso millet, Ibaekchal, Geumsilchal and Manhongchal developed by the National Institute of Crop Science were used. Silage corn and SSH were sown on May 21, 2019 and proso millet on June 4, and harvested on September 2. There was no significant difference in plant and ear height of silage corn among varieties. P1543 was the highest and P2088 was the lowest in yield of silage corn, but there was no significant difference among treatments. Among the SSH, the plant height of 877F was the highest and Turbo gold variety had the smallest (p<0.05). As for the dry matter(DM) yields, 877F had the highest at 3,862 kg/ha and Green star had the lowest at 2,669 kg/ha (p<0.05). The fresh matter yield of proso millet was 15,778 kg/ha, which was higher than that of corn or SSH, The average dry matter yield was 4,780 kg/ha, and Ibaekchal variety had the highest DM yield compared to other varieties (p<0.05). P2088 had the highest TDN content and GPO was the lowest (p<0.05). As for the SSH, the TDN content of Green star and Honey chew varieties was significantly higher, and the RFV value was the lowest in Turbo gold. The average crude protein content of proso millet was 7.03%, and the highest TDN and RFV values were 64.36% and 106 in Geumsilchal. In the experiment of the germination rate of summer forage crops according to salt concentration, silage corn showed a germination rate of 83.1% even at 0.4% salinity. In particular, P2088 and P1921 varieties had more than 80% germination rate even at 0.6% salt concentration. As for the SSH, the germination rate of 877F was 93.3% even at 0.8% salinity, and 88.3% with Honey chew, indicating higher resistance to salt concentration compared to other varieties. Proso millet showed a high germination rate of 84.0 to 88.7% even at a salt concentration of 0.6%. Considering the above results, proso millet was recommended as the most suitable forage crop species in the Sihwa reclaimed land with high salt concentration, and the Ibaekchal variety is recommended as a suitable forage crop due to its high yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.137-152
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• 2009

Present experiment was conducted at the field of Gyeongnam Agricultural Research and Extension Services in Jinju city for two continuous cropping seasons to develop several adaptable and valuable year-round forage-producing system for elevating self-sufficiency and dollar-saving by reduced importing of crude forage. Twenty cropping systems were tested in experiment using whole crop barley (WCB), oat, rye, Italian ryegrass (IRG), and triticale in winter season and com, sorghum, sorghum ${\times}$ sudangrass hybrid, and oat in summer time. Sorghum ${\times}$ sudangrass hybrid showed highest fresh forage yield among experimented summer season crops, and followed com. Com produced the most dry matter yield, and followed sorghum${\times}$sudangrass hybrid, sorghum and oat in order. There was no significant effect of former winter crops on fresh and dry matter production succeeding summer time crops. Among winter season forage crops tested, oat showed the highest fresh and dry matter when clipped on mid-May, and followed triticale, IRG, rye and WCB. Winter-time cultivated crops showed no clear effect on the growth and forage (fresh and dry matter) producing ability of following summer crops. There was the most protein content in oat plant among summer season planted crops, and in sorghum for acid detergent fiber (ADF) and in sorghum ${\times}$ sudangrass hybrid for neutral detergent fiber (NDF), respectively. While, com showed highest value of relative feed value (RFV) and total digestive nutrients (TDN) among those crops. Among winter crops, the highest crude protein was in oat plant showing no significant differences of ADF and NDF, while, relatively higher value of RFV was recognized with rye and triticale. Also, triticale contained more TDN as compare to other forage crops. The cropping combinations such as com followed by (fb) rye and maize fb triticale were regarded as promising systems having higher dry matter producing ability among tested combinations. Considering TDN producing potential, the combinations with sorghum ${\times}$ sudangrass hybrid fb triticale andlor rye were would be suitable ones, coincidently. There was a tendency which elevating pH, electric conductivity (EC) and organic matter (OM) contents in soil after experiment comparing to before planting. More crude protein content in plant was shown at mid-May clipping as compared to the forage at April cut in all winter season grown crops. ADF and NDF contents were increased by delayed clipping showing decreased tendency of RFV and TDN in plant. In conclusion, many cropping systems would be available using above mentioned forage crops according to farmer's conditions and scale, etc.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.131-136
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• 1985

This experiment was conducted to identify the competitive ability of rice against Monochoria vaginalis Presl. and to determine effect of various herbicides on it. Photosynthetic efficiency of rice markedly increased as the density of M. vaginalis increased from 1 to 3 plants per hill. Competition index increased in propotional to an increase of M. vaginalis density while total dry matter of rice decreased in reverse. Significant yield reduction of rice, was observed at the density of M. vaginalis, 2 plants per hill and 37% at 3 plants per hill. Such a yield reduction can be mainly attributed to the decrease of panicle and spikelet number of rice which were greatly affected by competition with M. vaginalis. Regardless of herbicides tested, % inhibition increased remarkably as the concentration of herbicides increased from 1 to 20 ppm. No plant growth was observed in all the herbicides treated with 20 ppm except for butachlor, thiobencarb and bifenox, showing existence of the new promising herbicides to control M. vaginalis among the herbicides tested.