Soybean is one of the important food crop around the world. Especially in East Asia, it is the main ingredient for traditional food like soy sauce and soy paste. The double cropping system including soybean following onion, Chinese cabbage, and potato is widely adopted in Southern region of Korea. In this system, sowing date of second crop (soybean) can be delayed depending on first crops’ growth period and weather condition. When planting date is delayed it is known that soybean yield is declined because of shorter vegetative growth period and earlier flowering induced by warm temperature and changes in photoperiod. The objective of this study was to determine soybean growth and yield responses as plant populations at late planting date. Field experiment was conducted at Department of Functional Crop, National Institute of Crop Science, RDA located in Miryang, Gyeongsangnam-Do for two years (‘13-’14) in upland field with mid-late maturity cultivar Daewon. A split-plot block design was used with three replications. Main plots were three sowing dates from June 20 to July 20 with 15 days intervals, and subplots were 4 levels of planting densities. Data of maturity (R8) was recorded, yield components and yield were examined after harvesting. Experimental data were analyzed by using PROC GLM, and DMRT were used for mean comparison. Optimum planting population for maximizing soybean yield in late planting which compared with standard population. In mid-June planting, higher planting density causes increased plant height and decreased diameter which lead to higher risk of lodging, however, reduced growth period due to late planting alleviated this problem. Therefore higher seeding rates can provide protection against low seedling emergence caused by late planting in this region.

This experiment was carried out to determine the optimum planting density for rice pot seedling cultivation in wheat-rice double cropping system in Honam plain area. A mid-late maturing rice variety ‘Chinnong’ was raised in pot seedling tray and conventional tray for 30 days, and then transplanted on June 25 in 2012 and 2013. Four different planting densities (15.2, 18.9, 21.6, and 25.3 hills per m 2 ) in pot seedlings were applied as treatment. Conventional tray seedling was implicated as control at a single planting density of 27.8 hills per m 2 . In this experiment, the number of effective tillers was increased as planting density increasing, but stem diameter was decreased. Pot seedling showed higher stem diameter and effective tillers than the control. Heading dates of pot seedling plots were not significantly different between the planting densities but 2 days faster than the control. Culm length, number of panicles, panicle length, and ripening grain ratio were higher in pot seedling compared to the control, but 1000-grain weight showed no significant difference. Milled rice yields in pot seedlings ranged from 5.19 to 5.43 t ha -1 , and the highest yield was observed in 21.6 hills per m 2 . Head rice ratios in pot seedlings and the controls were not significantly different. Above results on planting density of rice pot seedling cultivation would be applicable to wheat-rice double cropping and also to late transplanting cultivation of rice single cropping.

Fresh edible sweet corns demand relatively short period to harvest fresh ears, which can allow farmers to make a choice sweet corns for various cropping systems. For this reason, we were to find the optimum planting date of late-planted sweet corns to sell fresh ears in the autumn linked to cropping system with winter crops, investigating yield and properties of marketable fresh ears and growth traits of sweet corns (cv. 'Godangok' and cv. 'Guseulok') depending on planting dates such as 10 July, 20 July, and 30 July in Suwon 2012 and 2013, respectively. The 20 July-planted sweet corns showed the most fresh ear yield. However, the 10 July-planted and the 30 July-planted had 32% less yield caused by consecutive rainfall from 10 July through 20 July, and 15% less yield due to low air temperature during ripening than the 20 July-planted, respectively. The 10 and 20 July-planted sweet corns had average 140g of a fresh ear weight and 15% heavier ear than the 30 July-planted. For the July-planted sweet corns, silking days after planting (r=-0.80**), and harvesting days after silking (r=-0.97**) and planting (r=-0.91**) were highly negatively correlated with daily mean air temperature during the period, resulting in it takes 1,100 growing degree days (GDD) to harvest fresh ears from the July-planted sweet corns. The fresh ears of the 20 July-planted sweet corns are able to be harvested by early October. Therefore it will be a good choice for the cropping system based on winter vegetable cash crops such as temperate garlic and onion with medium or late maturity. Among three planting dates 20 July-planted sweet corns had the best field performance in every year considering fresh ear yield, ear size, and stability to grow.

Maize is expected to be planted in June after harvest of winter barley for the double cropping of forage maize-barley. But maize yield tends to be reduced rapidly with late planting after mid-May, so the pre-requisite of maize variety for the double cropping of maize-barley is less reduction of growth and yield at the condition of late planting in June. In order to select domestic forage maize variety adapted to late planting in June after barley harvest, Kwangpyeong-ok, Gangda-ok and Jangda-ok in 2007 and Kwangpyeong-ok, Gangda-ok and Cheongan-ok in 2008 were planted on June 13 and June 21, and plant growths and yields were compared with early planting on April 24 and May 31, respectively. In 2007, Ear number per plant was as high as 0.98 at Kwangpyeong-ok compared to 0.89 and 0.56 of Gangda-ok and Jangda-ok, respectively, at late planting on June 13. TDN and grain yield of Kwangpyeong-ok were the highest among three variety as 1,037 and 710 kg/10a, and yield reduction of Kwangpyeong-ok compared to early planting were 24% and 28 %, which were 7% and 8% lower than Gangda-ok and 22% and 50% lower than Jangda-ok, respectively. In 2008, TDN and grain yield at late planting on June 21 of Kwangpyeong-ok were also the highest among three varieties as 1,157 and 854 kg/10a at late planting on June 24, and yield reduction of Kwangpyeong-ok by late planting were 21% and 19%, which were 10% and 11% lower than Gangda-ok and 22% and 50% lower than Jangda-ok, respectively. It was concluded that proper maize variety adapted to late planting for the double cropping of forage maize-barley was Kwangpyeong-ok because of its higher ear bearing, less reduction of TDN and grain yields at the condition of late planting.

Manpung is a new japonica rice cultivar developed from three-way cross between Nakdongbyeo, Iri390 and Milyang111 by the rice breeding team of National Honam Agricultural Experiment Station (NHAES), RDA in 2000. This cultivar has a short grain shape and a

Mananbyeo was developed from a three way cross ilyang110/Yeongdeog7//Milyang110 in 1999. It has short growing duration about 71 days from seeding to heading and short culm length of 75 cm. It has almost similar number of panicles per hill , spikelets per

조숙옥수수를 포함한 사료작물 작부체계 구성시 조숙옥수수의 생산성을 확보하기 위해 만파시밀식재배를 시도하였다. 조숙옥수수로는 Comet80, Comet85, Linda 품종을 이용하였고 만파정도는 수원19호 적기보다 45, 55, 65일 만큼 늦게 파종하였다. 파종밀도는 각 파종기에 대하여 60 20, 50x20, 40 20cm로 밀식정도를 달리하였다. 각처리구의 수확은 8월 29일 일괄실시 하였는데 조숙옥수수의 이러한 처리에 따른 수량구성특성 변화와 조숙옥수수의 촉과작물 작부체계도입 가능성을 조사한 결과를 요약하면 다음과 같다. 1. 6월 22일까지 파종에서 건물수량은 Comet85, 수원19호 Comet80, Linda 순이었다. 2. 6월 12일까지의 파종에서 수원19호의 이삭비율은 6.7%이었는데 비해 Comet80, Cometss, Linda의 평균 이삭 빈율은 40.3%이었다 3. 조숙품종의 밀식에 의한 건물수량 보상효과정도는 6월 22일까지 파종에서 20x50cm밀도가 20 60cm밀도에서 보다 평균 37.3% 증수하였다. 4. 만파시 Comet85는 수원19호보다 평균 24.1 % 많은 TDN을 생산하였다.