• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.50-54
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• 1984

To study the effects of planting dates and mulching on the growth and yield of summer type soybean, a variety, Damamidori introduced from Japan, was planted four times from April 13 with 10 days interval. Experimental plot in each planting date was devided into two sub-plots, polyethylene film mulching and non-mulching. By mulching, days to emergence and first flowering were shortened, especially in the early plantings; e.g. as much as 11 and 12 days, respectively, in the first planting. Compared to non-mulching, plant height, number of nodes of main stem, number of branches, and dry weight of stem and branches per unit area were also much increased by mulching. As the plantings were delayed, plant height, the total number of nodes and dry weight of main stem and branches, and 100 seed weight showed increasing trends, which were mainly due to lower infection rate of soybean seeds to pod and stem blight (Diaporthe phaseolorum) in the later plantings. The higher infection rate of soybean seeds to pod and stem blight, the lower infection rate to purple seed stain (Cercospora kikuchii) was shown in mulching but not in non-mulching.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.2
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• pp.113-117
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• 1978

An attempt was made to establish a mass-screening technique for resistance to purple seed stain .disease in soybean. Seeds sterilized in 1 : 10000 'mercuric chloride for 1 minute and transffered to Petridishes containing 20ml water agar plus 50ppm of the sodium salt of 2,4-D were inoculated by placing a small agar cube containing fungal mycelium on the seed coat of each seed. A positive correlation between natural infection of purple seed :stain and purple discoloration by seed inoculation technique was highly significant and by this technique, some native soybean collections and introduced varieties were tested for resistance to the disease. Most of the soybean varieties tested were susceptible except for the varieties Hill, Harosoy and Sac, resistant comparatively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.178-187
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• 1996

This study was conducted to obtain the basic informations for producing high quality seeds of vegetable soybeans. Four vegetable soybean cultivars, 'Okharawase', 'Mikawashima', 'Hwaeomputkong', and 'Seokryangputkong' were planted at four locations, Chulwon(altitude, 192m) and Pyeongchang(altitude, 370m) in highland, and Suwon(altitude, 37m)and Daegu(altitude, 55m) in lowland of Korea with two planting dates, May 15 and June 15. Seed infection rates were attributed by in order of phomopsis seed decay caused by Phomopsis spp., seed mottling caused by soybean mosaic virus (SMV), purple seed stain caused by Cercospora kikuchii. Seed infectron rate was the lowest at Pyeongchang and lower on June 15 than on May 15 planting. Phomopsis seed decay by Phomopsis spp. was lower in highland of Korea, Pyeongchang and Chulwon, than in lowland of Korea, Suwon and Daegu. Seed infection rate was also lower on June 15 planting than on May 15, and in seeds harvested at maturity than at ten days after maturity. Germination rate of seeds harvested in highland, Pyeongchang and Chulwon, after six to seven month storage at 5$\pm$1$^{\circ}C$ was more than 90% and higher than that of the seeds in lowland, Suwon and Daegu. Germination rate was also higher on June 15 than on May 15 planting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.44-51
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• 1995

This investigation was conducted to determine the effect of the optimum planting date and place for good seed production on growth variation, grain yields, different of variety, infection of seed by fungi, and seed germination and vigor after room storage. Early maturity Korean soybean variety, Keunolkong, and introduced vegetable soybean variety, Fukura-edamame, were planted at field of YAES. and high cool land of Sajapyong in Milyang（altitude, 850m） on May 15 （early）, June 15 （mid.）, and July 15 （late） in 1991. The emergence and vegetative period gradually increased in the early planting date. The grain yield, seed weight, pod number, healthy grain yield also increased when Keunolkong was planted on early date. The healthy seed rate, Keunolkong increased in the early planting date, whereas that of Fukura also increased in the late planting date. Infection ratio of grain to phomopsis seed decay （Phomopsis spp. ' Diaporthe phaseolorum） in Fukura steadily increased in the early planting date. Infection ratio of grain to purple seed stain （Cercospora kikuchii） generally increased in the mid and late planting date. The seed germination and seedling vigor after room storage from five to six months gradually increased in the late planting date. And seed germination of Fukura rapidly decreased in the early planting date. Therefore, the optimum planting date for good seed production in early maturity vegetable soybean was June 15 in terms of harvesting time avoid a high temprature and humidity.