• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.239-244
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• 2014

Barnyard grasses are dominant weed that are not eliminated easily in the direct water seeding cultivation. So, deep water treatment can reduce their growth at the early growing stage of submerged paddy. This study was carried out to investigate the reducing growth of the barnyard grasses through flooding at seedling stages of rice plant in the green house. Under the normal condition, the plant height of rice variety, Samgwangbyeo, and 3 species of barnyard grass, E. caudata, E. pratocola and E. utilis were not showed the difference up to 10 days after seeding while the plant height of 3 barnyard grass species, especially E. utilis, was more elongated than the rice at 25 days after seeding. Plant height of the 3 barnyard grasses were not elongated largely during 3, 5 and 7 days of flooding treatment at 10 days after seeding. Interestingly, the rice seedlings was grown over 20 cm, and the flooding tolerance of rice seedling was higher than the 3 barnyard grass varieties. However, after flooding treatment for 3, 5 and 7 days, the elongation of plant height of 3 barnyard grasses, especially E. utilis was more speedy compared to rice seedlings as 6 to 9 days passes. And the protein spots from barnyard grasses were also reduced and eliminated more than the spots of rice seedling after flooding treatment.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.50-57
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• 2020

BACKGROUND: Biochar is used in various environmental fields, such as water quality and soil restoration, and affects soil fertility and nutrient cycling. Also, when crops are grown on biochar-applied soil, their characteristics may be affected. Biochar is used especially with commercial vegetable seedlings. METHODS AND RESULTS: The objective of this study was to determine the effects of biochar content in seeding mixes on early growth of lettuce (Lactuca sativa L.), Chinese cabbage (Brassica rapa L.), and red pepper (Capsicum annuum L.). Treatments consisted of a control (0: 10, ratio of biochar to seeding mixes (w/w)), 1: 9 (biochar 10%), 3: 7 (biochar 30%), 5: 5 (biochar 50%), and 7: 3 (biochar 70%). The biochar was made from risk husk and had a C/N ratio of 104. As the mixing ratio of biochar increased, pH increased whereas EC and nitrogen content decreased. The highest phosphorus content was with the treatment of 30% biochar, while there were significant increases in the weight of lettuce seedlings and concentrations of T-N, P₂O₅, K₂O, MgO, and Na with the treatments of 30% and 50% biochar. Although the weight of Chinese cabbage seedlings increased with the treatment of 10% biochar, the increase was not statistically significant. Also, there was an increase in the weight of red pepper seedlings with the treatment of 30% biochar, but the increase was not statistically significant. With increases in the biochar mixing ratio, the K₂O concentration of red pepper seedlings increased, but the concentrations of P₂O₅, CaO, MgO, and Na decreased. It was believed that this was because of absorption inhibition by calcium-phosphate formation in the seeding mixes owing to increased pH. CONCLUSION: In conclusion, adding biochar to seeding mixes is considered to be an important mean for growing healthy vegetable seedlings. More field experiments are needed to verify the effect of biochar on vegetable crop growth over the entire growing season.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.22-28
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• 2001

An optimum seeding date for carrots growing in Jeju was determined. In early growth stage, the number of leaves was more in Hyang-yang #2 cultivar (HY2) than that in the others, meanwhile that of Hukjun 5 chon (H5) and Shinhukjun 5 chon (S5) was higher in the latter half of the growing season. The weight of leaves was greater in HY2 until 2 months after seeding, but thereafter drastically increased and resulted significant difference at harvest in S5. The length of roots was greater in H5 and S5 than in HY2 when seeded on July 17 and measured after September 13, but it was similar in all cultivars when seeded on August 1 and later. The diameter of the roots was greatest in HY2, regardless of seeding dates, meanwhile no difference was found among other cultivars. The weight of roots was greatest in HY2 when seeded on July 17, August 1 or later, meanwhile it was greater in H5 after November, when seeded on August 15. The percentage of roots cracked was 20, 15, and 10% respectively for HY2, S5 and H5. The percentage of roots branched was 0.3% in HY2. The percentage of roots cracked or branched was much higher when seeded on August 1 than on July 17, and was high (40%) in HY2 and S5, compared to H5 when seeded on August 15. The content of sucrose, glucose and fructose increased until 110 days after seeding in all cultivars, but fructose and glucose contents decreased in about 135 days after seeding, but sucrose contents increased continuously even after 135 days. Sucrose content increased and fructose and glucose contents decreased in S5, but this trend was reversed after late November. Sugar contents was different among the cultivars seeded on August 15, while sucrose content decreased and glucose and fructose contents increased with time. The content of ${\beta}$-carotene was more than 12,000 IU in all cultivars, but decreased in 170 days after seeded on July 17. The content was highest in HY2 and followed by S5 and H5 in order. It was not different among the cultivars in 170 days after seeding on August 1, but was higher in S5 than the other cultivars in 170 days after seeded on late and decreased with seeding date.

• Korean Journal of Organic Agriculture
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• v.9 no.4
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• pp.95-111
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• 2001

To carry out the Integrated Fruit Production(IFP), researches on cover crops as well the Integrated Pest Management(IPM) and the Integrated Nutrition Management(INM) should be very important. These concepts are neither clear nor connective till now. The researches on cover crops in Europe and USA are being kept within the category of IFP. Main researches on fruit trees for sustainable agriculture in Italy are new variety creation, development of growing techniques, pest and disease control, and cover crops management, etc. It is necessary of fruit industry in Korea to maintain good quality and taco-friendly fruit production. For this goal, we need international cooperation with highly developed countries in Europe. In first step, we should enlarge research areas and analyze results obtained to get farmers understood the concept of cover crop growing, Furthermore, we make researches more profoundly on cover crops growing considering tree age, mixing rates among cover crops, seeding and cutting time for cover crops, and so on. Researchers, specialists of agricultural extensions, and farmers should concentrate their opinions and conduct IFP together. The IFP should go on systematically and reach finally to get certificates internationally by the International Organization for Biological and integrated Control of Noxious Animals and Plants(IOBC) to enhance selling and exporting fruits.

• Korean Journal of Plant Resources
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• v.31 no.1
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• pp.24-31
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• 2018

Amaranth (Amaranth caudatus) is attracting attention as a preference crop in Gyeongsangbuk-do province. To determine its growth potential and cultivation requirements, we investigated its growth characteristics, dry matter productivity, and grain yield according to the growing period. Growth and dry matter productivity were significantly higher for plants that were sown on May $10^{th}$ when the temperature was the highest, whereas the yield was significantly higher for plants that were sown on April $10^{th}$. Amaranth grain yield ranged from 96 to 243 kg according to the sowing date and cultivation year. The optimum harvest time for plants that were sown on April $10^{th}$, May $10^{th}$, and June $10^{th}$ were 120, 110, and 110 days after seeding, respectively. The mean temperature and growing period had a significant quadratic function with yield. Based on these equations, the optimum growing temperature was estimated as $20.6^{\circ}C$ and the optimum growing period as 104-119 days after seeding.

• Korean journal of applied entomology
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• v.36 no.1
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• pp.55-66
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• 1997

This study was conducted to analyze arthropod community patterns in small rice fields associated with different planting methods (water seeding, drill seeding, and hansplanting) in Suwon and Icheon in 1994. Total 15 orders and 45 families of arthropods were collected. The arthropod community was analyzed using guild categories. The arthropods were found in the order of 'natural enemy>pest(phytophage)>non-pest' in their densities in all sites. The pest (phytophage) species were mainly Homoptera and dominated by Delphacidae (Nilaparvata lugens Stsl, Sogatella fircifera Horvath and Laodelphax striatellus Fallen) and Cicadelidae (Nephotettir cincticeps Uhler). They constituted >80% of pest abundance. Differences in pest abundance were not found among rice fields associated with different planting methods. Spiders were the most dominant group in the natural enemy and constituted >90% of natural enemy abundance. Hunting spiders constituted >SO% of spider abundance and were dominated by Pirata subpiraticus Bos. et Str. (Lycosidae). Pacliygnatha clerki Sundevall (Tetragnathidae) was a dominant species in webbing spiders. No differences were found in species richness and diversity in spider community among rice fields associated with different planting methods. The nonpest species were mainly Diptera and occurred abundantly in early growing season and decreased drastically as rice development proceeded. The non-pest abundance was higher in direct seeding sites than in transplanting site, and especially abundant in a drill seeding site.

• Current Research on Agriculture and Life Sciences
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• v.19
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• pp.1-8
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• 2001

This experiment was conducted to determine the effect of nursery soils and seeding density on seedling growth characteristics in automatic facility for raising of rice seedlings. The seedling characteristics were evaluated for the 10-day and 15-day old seedlings grown in six different nursery soils including farm-made soils. Two levels of seeding amount, 250 g and 300 g/tray ($60{\times}30{\times}2.5$ cm), were applied to compare the seedling characteristics according to seeding density on different nursery soils. There were wide difference in soil components among the nursery soils tested. In acidity of nursery soils, 'Bunoog 2' was the highest, pH 5.1, and 'Samkyung' was the lowest, pH 8.6. The content of available phosphate was the highest value, 843 ppm, in 'Bunong 1' and the lowest (74 ppm) in farm-made soils. The total nitrogen content of 'Bunong 1, 2, 3' and 'Weonjo' soils was higher than there of 'Samkyung' and farm-made soils. There was no difference in plant height among three types of 'Bunong' soils (Bunong 1, 2, 3), but the seedling height grown in farm-made soils was shorter than there in other nursery soils. The plant heigh was slightly taller as the increase of seeding amount from 250 g to 300 g/tray, and the difference in plant height was larger in 15-day old seedlings as compared with 10-day old seedlings. Dry weight of seedlings grown for 15 days in three 'Bunong' soils was heavier than those in other nursery soils. Based on the growing characteristics of seedlings grown in different nursery soils, the heat result was obtained from a nursery soil, 'Bunoog 2', among six marketing nursery soils tested.

• Korean Journal of Environmental Agriculture
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• v.33 no.1
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• pp.9-16
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• 2014

BACKGROUND: This study was conducted to investigate the effects of seeding timing and method of rye and/or hairy vetch on seasonal soil and foliar nutrient concentrations as well as fruit quality in a pesticide-free pear orchard. METHODS AND RESULTS: The treatments included as followed: single seeding of rye in September (Sep-Mono), November (Nov-Mono), and January (Jan-Mono), or mix seeding of rye+hairy vetch in November (Nov-Mix) and January (Jan-Mix), or sod culture as a control. Cover crops or vegetation was mown and mulched on the soil surface in April and May for two years. Nov-Mix treatment produced the highest dry matter weight of $12,070kg\;ha^{-1}$, with the lowest dry matter weight for sod culture ($6,520kg\;ha^{-1}$), following Jan-Mix ($7,030kg\;ha^{-1}$). Nov-Mix treatments increased potential amount of N, P, and K from the raw materials of the cover crops as well as improved soil physical properties. Nov-Mix treatments overall elevated soil pH, EC, organic matter, and $P_2O_5$ in May compared to other cover crop treatments or sod culture. The difference of the seasonal nutrient concentrations in leaves or fruit qualities were not consistently occurred amongst treatments. CONCLUSION: Nov-Mix treatments showed playing role in a substitute of a chemical fertilizer. Delayed seeding of cover crops such as Jan-Mix did not increase the potential dry matter production due to the short growing period, and the seeding time would affect the dry matter production of cover crops.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.52-57
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• 1987

To know the effects of weeding periods (weeding from 12 days, 28 days and 42 days after seeding to harvest, and weeding from seeding to 14 days, 28 days and 42 days after seeding) and growing conditions such as transparent polyethylene film mulch (P.E. mulch) and bare soil on growth and yield of peanuts, "Yeongho-Tangkong" was planted on May 10, 1984. Under P.E. mulch, the number of weeds was higher, but the weed dry weight was lower than in bare soil by the middle of July. Sixty days after seedings, the length of main stems in weedy check plots was longer, but shoot dry weight was lower compared to weed free plot. In the correlation coefficients between weed dry weight and the shoot dry weight of peanut on July 14, the growth retardation of peanuts due to weeds was showed earlier under P.E. mulch than in bare soil. Shoot dry weight, shelling ratio, number of seeds per pod, 100 pod weight, and seed yield were higher under P.E, mulch compared to bare soil. But weed dry weight, length of branches, number of pod bearing branches, number of pods per square meters, and pod yield were similar between P.E. mulch and bare soil. Shoot dry weight of peanuts, length of branches, number of pod bearing branches, number of pods per square meters, pod yield, 100 pod weight, 100 seed weight, and seed yield in weed free plots from 28 days after seeding to harvest (28 DAS-Harvest) were higher compared to weed free plots from 42 DAS-Harvest. However, in the weed free plot from seeding to 42 days after seeding seed yield was lower than that of the continuous weeding plot due to lower number of pod bearing branches and number of pods per square meters. When weed was not controlled at the later growth stages of peanuts, reduction in seed yield due to weeds was greater in bare soil than that under P.E. mulch.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.320-327
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• 1990

Experiments were conducted to investigate the method to raise seedling establishment rate and the optimum seeding dates and rates in direct seeding culture using transplanter under submerged field condition in Chuncheon area during 1986 to 1988. Direct seeding on submerged field using transplanting machine after sowing on seedling growing box contained with paddy or upland soil was possible. Higher rate of seedling establishment was obtained in case of sowing sprouted seed and intermittent irrigation after sowing. Seedling establishment rate was higher both in April 30 or May 10 seeding plot. Minimum daily average air and soil temperature to ensure more than 70 percent seedling establishment was 14.8$^{\circ}C$ and 16.3$^{\circ}C$ respectively. Optimum sowing date in the direct sowing was early May and optimum sowing rate was 200g per box, 6kg per l0a. In this case rice grain yield was 481kg per l0a and this is almost same yield level compared hand and machine transplanting.