• Korean Journal of Medicinal Crop Science
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• v.9 no.3
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• pp.198-204
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• 2001

$GA_3$ treatments for seeds of Perilla frutescens var. acuta Kudo were evaluated as a means of improving the percent germination, and the interactions of $GA_3$, mulching, and sowing depth on seedling emergence were investigated in late sowing. Percentage germination of seeds treated with different concentration of $GA_3$ was the most effective in 100 ppm treatment for 24 hours. The germinability according to the seeds soaking time was not significantly different over 12 hours in 100 ppm $GA_3$. At high temperature $(25^{\circ}C\;and\;30^{\circ}C)$, percentage germination was significantly increased in 100 ppm ${GA_3}$ treatment. In late sowing (1th or 15th May), seedling emergence was significantly higher in 100 ppm $GA_3$ treatment than nontreatment, and that was significantly increased when the seeds treated with 100 ppm $GA_3$ were mulched with 10 mm rice hull after molding with 5 mm soil depth.

• Korean Journal of Organic Agriculture
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• v.17 no.4
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• pp.529-538
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• 2009

This study was conducted to investigate the sowing time and sowing methods of the Rye(Secale cereale L.) for an organic soybean farming system. It can be seen that there was no significantly differences on soil chemical properties in the rhizosphere due to the Rye's sowing season. A soil chemical properties due to the Rye's sowing date in spring, O.M.(g $kg^{-1}$) contents was increased at a late Rye's sowing dat, while on the other pH, Avail. $P_2O_5$(mg $kg^{-1}$) and CEC(cmol+ $kg^{-1}$) were decreased. A highest yields of soybean was achieved at the plot which the Rye was sowed on 20th March with two-line, 5 row and 70cm row-space.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.584-592
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• 2006

This study was conducted to investigate the effects of sowing date on yield component and yield in sprout-soybean. Six sprout-soybean cultivars were planted on three sowing dates in 2000 and 2001. 100-seed weight, number of seeds per pod, number of seeds, number of pods per plant, and ratio of empty pods distinct differences between sowing dates and cultivars. All yield components except the 100-seed weight and number of seeds per pod diminished recording where the sowing day will be late. The ratio of pods with two or three seeds was 77.5 from 80.9 percents. The ratio of two-seed pods were affected by sowing date. The yield of soybean of May 25 sowing was 290 kg/10a followed by June 15 and July 5 sowing with 269 kg/10a and 221 kg/10a, respectively Late sowing greatly decreased the yield of Doremikong, while yields of Tawonkong were more a less stable. In 2000, yield showed positive correlation with number of branches, number of pods per plant, number of seeds per plant, dry weight, leaf area, and oil content. While yield of 2001 showed positive correlation with number of nodes on main stem, stem thickness, number of pods per plant, dry weight, and leaf area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.368-373
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• 1983

To study the grain development and quality during wheat grain-filling under different sowing date and region, the experiments were conducted from 1978 to 1979. The grain weight at the early grain-filling stage in Suweon was heavier than in Gwangju, but the weight at the late grain-filling stage was reversed. The ranges of the physiological maturing period in the optimal sowing for 2 years were from 43 to 49 days in Suweon and from 44 to 51 days in Gwangju. These showed the tendency of lengthened grain-filling periods in southern region, and the periods were 1-4 days longer in optimal sowing than those in late sowing. Wheat grain quality was affected significantly by environmental conditions. The milling rates were increased in southern region where the plumpness of grain was better, the protein content and sedimentation value were higher in northern region where the temperature during grain-filling was high.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.305-305
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• 2017

Seoritae with green cotyledons refers to Korean native black beans harvested when the frost falls because the maturity is late. It is one of the beans preferred by consumers because of its softness and high sugar content. Because of late maturity, if the agricultural work is delayed by weather or agricultural schedule in green cotyledon black soybean (Seoritae), it affects seriously harvest and yield of soybeans. The aim of this study was to investigate the marginal seeding period on June 30, July 10 and July 20 in Cheongju and Jecheon area in Korea to produce stable soybean yield. The yields of green cotyledon black soybean as seeding date in Cheongju area are as follows: Seolitae (Yeoncheon), Seoltae (Goesan) and Seoritae (Gogseong), which increased by 23%, 56%, 23% and 40%, respectively, compare to July 10th to June 30th. As soybean sowing is delayed, the quality of soybean seeds has decreased due to the increase of immature seeds and fungal damaged seeds. The contents of anthocyanin in Cheongju area a functional substance of soybeans, was high on July 20 for Heukcheong, on June 30 for Seolitae (Yeoncheon), on July 10 for Seoritae (Goesan). The yields of Heukcheong and Seolitae (Yeoncheon) in Jecheon area were increased by 5% and 17%, respectively, compare to July 10th to June 30th, while Seolite (Goesan) and Seolite (Gogseong) were high in yields on June 30th. Similarly in Cheongju area, as the sowing period is delayed, the number of immature and mold damaged seeds in Jecheon area increased. The contents of anthocyanin in Jecheon area was high on July 10 for Heukcheong, on June 30 for Seolitae (Yeoncheon) and Seolitae (Goesan). From the above results, Sowing marginal date of green cotyledon black soybeans (Seolitae) in Cheongju area increased 30% in sowing on July 10 and increased 2% in sowing on July 20 compared to June 30. And Sowing marginal date of green cotyledon black soybeans (Seolitae) in Jecheon area increased 2% in July 10 compared to June 30, and the yield decreased rapidly on July 20. We have identified the seeding time limit of green cotyledon black bean in Chungbuk province. It will be possible to provide a variety of crop selection after double cropping of farmers. And by knowing the yield and seed quality of soybean according to sowing date, farmers will observe appropriate sowing period of soybeans for high quality. From the viewpoint of consumers, functional substances of Seoritae will meet the desire for health.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.269-273
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• 2006

Multiple linear regression analysis was conducted to interpretate the relationship between sesame grain yield and its components under early sowing cropping condition. The t test showed that stem length, number of capsules per plant, 1000 seeds weight and seed weight per plant gave significant contribution to sesame grain yield, therefore those variables were assumed to mostly influenced components to grain yield of sesame. In the stepwise regression analysis, the predicted equation for sesame grain yield per square meter (Y) was Y = -7.900 + 0.150X1 + 0.461X5 + 15.553X6 + 8.543X7. Meanwhile, F value showed that stem length, number of capsules per plant and seed weight per plant gave significant contribution to sesame grain yield, while 1000 seeds weight did not significantly show. Based on the results, it is reasonable to assume that high yield. potential of sesame under early sowing cropping condition would be obtained by selecting breeding lines with long stem length, number of capsules per plant, and seed weight per plant, which was different result at the late sowing cropping condition in which days to flowering and maturity were assumed to be more affected factors to the sesame grain yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.179-184
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• 1981

The study was conducted to know the differential growth responses of soybean cultivars as affected by various application stages of Metribuzin herbicide, at the University experimental farm of Chonnam Nat'l. Univ, Kwangjoo, 1980. Experimented soybean materials were six cultivars, as Kwanggyo, Dongbuktae, Bongui, Yukwoo 3, Suweon 85, and Suweon 86., . and Laid-out application stages were five as pre-sowing, Pre-emergence, Early Post-emergence, and Late Post-emergence treatment comparing with Control. Results obtained from the study were as follows: Among experimented soybean cultivars, no significantly tolerant cultivar was shown. Highly significant differences in phytotoxicities by Metribuzin treatments were detected among various application stages, and crop tolerances were recognized bigger in order as E. Post-emg. < L. Post-emg. $\ll$ Pre-emg. < Pre-sowing $\leq$ Control. The phytotoxic symptoms of all soybean cuitivars were severely recorded in order of Leaf No. /Plant < Plant height $\ll$ Branch No. /Plant. For the cultivation of most soybean cuitivars, the use of Metribuzin in Pre-sowing or Pre-emergence were recommended, and especially it is expected to follow of more detailed study on soil-incorporation method in Pre-sowing treatment, and rather the tank-mixture system of Metribuzin with others than the mono-application system for the safe-use and enlargement of weeding-spectrum.

• Journal of Practical Agriculture & Fisheries Research
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• v.9 no.1
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• pp.91-104
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• 2007

The special project was conducted at the cooperative farm where located at Yakjeon-ri Sukcheon-gun Pyeongannam-do, the Democratic People's Republic of Korea. This farm was firstly introduced a newly developed technology-"Bokto seeding technology" for rice cultivation from the Republic of Korea. Total acreage of rice paddy field cultivated by this technology was 800ha and the average yield was 7.17t/ha with paddy rice which was higher by 109.2% than that of the transplanting method for rice cultivation. In general rice disease was decreased at the Bokto seeded rice plant compared to the transplanted rice plant and root activity was higher in Bokto seeded rice. Optimum seeding amount was determined at rate of 90kg/ha in Pyeongdo 5(early ripening variety) and 110kg/ha at Pyeongdo 11(medium ripening variety) and Pyeongyang 43(late ripening variety), respectively. A recommended sowing time was within late April for late ripening variety like Pyeongyang 43, May 1-5 for medium ripening variety, and May 5-15 for early ripening variety.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.79-86
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• 1973

In order to investigate the heading responses of naked barleys and their grain yields under the different sowing times in spring sowing at 9 levels and to select the promising variety, present work was carried out with 11 recommended naked barley varieties and 2 newly developed lines for the period of 3 years from 1971 to 1973 at Iri, these results being summarized as follows: 1. Under spring sowing cultures, 'Wanju naked barley' being spring habit showed the highest yields among them. However, Sedohadaka and Bangju being winter habit were also considered as the promising varieties. 2. In the case of sowing the spring type naked barleys in spring the optimum sowing time of barleys at Iri was estimated in the late of February or the early of March. 3. The number of main culm leaves and tillering per hill of 'Wanju naked barley' were not influenced at sowing times. But winter type barleys being sown in spring, they were outstandingly increased in accordance with the sowing time being late, especially after the critical sowing time. 4. In comparison with average days from germinating to heading date under different seasonal sowing at the same variety, 'Wanju naked barley' took 64.4 days to get heading and Kikaihadaka and Hyangchoen gwa, the low spring growing habit varieties, 72-73 days. 5. Young spikelet differentiation stage (length of young spikelet: 0.3-0.5mm) arrived at about 30 days before heading date in comfortable sowing time without regarding spring or winter type. But number of main culms disclosed great differences among them; barleys being high spring type were 4 leaves and low about 6. 6. In the view of morphology, culm length under the different seasonal sowing could not be found out differences in the high spring type barleys, but in the low, it was grately shortened by postponing the sowing time. The barley height of rosette form had no difference at any sowing time.difference at any sowing time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.313-326
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• 2023

Owing to adverse weather conditions, there is a heightened focus on actively researching the regulation of the sowing date in field crop cultivation. Soybean, a prominent field crop with extensive acreage and production, is a photophilic and thermophilic crop characterized by short-day photoperiodism. Identifying the optimal sowing time is crucial for mitigating the effects of severe weather conditions on soybean yield. Precise control over the timing of soybean sowing is the key to minimizing yield reduction due to unfavorable weather conditions. Temperature, photoperiod, and their interplay are the most significant factors influencing soybean cultivation among various weather factors. We conducted an experiment using three Korean soybean cultivars with varied maturities (Hwangkeumol: early maturing and Daewonkong and Pungsannamulkong: late maturing) in 2013 and 2014. Our investigation covered aspects of soybean growth, development, yield components, isoflavones, and visual seed quality. Across all three varieties, isoflavone levels increased with later sowing dates, while other measured components exhibited significant variations based on the sowing date. This study also provides valuable insights for the selection of suitable cultivars that perform well in soybean cultivation at various durations of maturity.