• 한국작물학회지
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• 제32권1호
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• pp.86-91
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• 1987

우리나라 사람들의 기호에 알맞는 단옥수수의 수확적기를 구명하기 위하여 3개 보통단옥수수 품종(Great Bell, 단옥 001, Golden Cross Bantam)과 초당옥수수 1개 품종(Crisp Super Sweet 720)을 공시하여 1985년과 1986년에 걸쳐 시험하였다. 시료를 출사 후 15일부터 27일 혹은 33일까지 3일간격으르 심취하여 성숙과정에 따른 종실의 발달, 당, 가용성 고형물, 맞 등의 변화와 이들 상호간의 관계를 조사하여 수확적기를 결정하였으며 그 결과를 요약하면 다음과 같다. 1. 보통단옥수수인 Golden Cross Bantam은 출수후 15일부터 33일까지 입중. 종실건물비율, 전분함량이 계속 증가하였으나 초당옥수수인 Crigp Su-per Sweet 720은 출사 후 27일 이후에는 이들의 증가가 완만하였고 전분축적도 Golden Cross Bant-am보다 훨씬 적었다. 2. 가용성 고형물은 3개 보통단옥수수 품종은 출사 후 27일 혹은 33일까지 증가하였으나 Crisp Super Sweat 720은 24일까지 증가한 후 30일 까지는 같은 수준으로 유지한 후 감소하였다. 수확기의 가용성 고형물은 보통단옥수수 품종이 Criap Super Sweat 720 보다 훨씬 높았다. 3. 종실의 sucrose, fructose. glucose 함양은 3개 보통단옥수수 품종에서는 출사 후 15일에 1∼2％로서 비슷하였으나 그 후 fructose와 glucose는 감소하고, sucrose는 출사 21∼24일까지 증가한 후 감소하여 전당함양은 출사 후 15∼21 일까지는 높게 유지된 후 급격히 감소하였다. 초당옥수수에서는 sucrose, fructose, glucose 모두 출사 후 24 일까지 증가한 후 감소하였다. 따라서 수확기의 주된 당성분은 Sucrose이었으며 최고전당함양은 보통옥수수보다 2∼3배 높았다. 4. 맛을 기준으로 한 수확적기는 출사 후 27일이었다. 가변성 고형물과 맛과는 같은 품종에서는 정의 상관이 있었으나 전당함량과 맛과는 관계가 없거나 부의 상관이 있었다. 전당함양과 가용성 고형물과는 관계가 없거나 부의 상관이 있었다.

• 한국작물학회지
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• 제46권4호
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• pp.317-320
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• 2001

Sweet com seeds deteriorate faster due to low starch content than field com seeds when stored for a long tenn. This study had been conducted to observe the seed deterioration of four different sweet corns in a long tenn storage conditions in room temperature. Four kinds of sweet com genes (sh2, bt, su, and se) were harvested from 15 days to 50 days after silking with 5-day intervals. These seeds were stored in the room temperature and tested for germination percentages from 3 months to 18 months period with 3-month interval. su seeds germinated better than other types of gene. Hybrid Mecca which is sh2 gene germinated better when stored for 3 months to 18 months. For all genes, mean regression equations in relation to storage periods showed linear responses. For regression equation, the slope of sh2 gene was lower than that of su gene. The highest slope value was observed in bt gene showing faster deterioration rate. The rate at which seed deteriorates seems to be affected by the date at which it was harvested. The seeds that were harvested at the optimum time deteriorated more slowly than those which were not.

• 한국작물학회지
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• 제45권1호
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• pp.55-58
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• 2000

Germination of sweet and super sweet corn is lower than normal corn due to the higher sugar and lower starch contents of kernels. Sweet corn seeds are easily deteriorated in the field under the unfavorable condition, therefore it is important to identify the optimal harvesting time for seed production. This trial was conducted to investigate the responses of germination percentage of shrunken-2(sh2), brittle(bt), sugary(su), and sugary enhancer(se) hybrids in relation to harvesting dates. Eight hybrids of four different gene sweet corns were harvested at 15, 20, 25, 30, 35, 40, 45, and 50 days after silking(DAS). Germination test was performed using paper towel method. Mean germination percentages across eight hybrids showed the highest value at 45 DAS. There were significant differences among genes and within gene for germination. Shrunken-2 hybrid Mecca was higher than su hybrids for germination, indicating that sh2 would not be poorer than su Late harvesting beyond the optimal harvesting date might not be desirable because of more lodging and ear rots. Theoretical optimal harvesting date estimated from the regression equation was 40.9 DAS, however, practical date for harvesting would be a few days later than the estimated date if seedling vigor might be considered. Kernel dry weight per ear showed similar response to germination. Regression equation showed the highest kernel dry weight at 40.7 DAS. Significant correlations between kernel dry weight and germination were observed, impling that kernel dry matter accumulation would be an important factor for germination.

• 한국작물학회지
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• 제36권1호
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• pp.52-56
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• 1991

인산흡착력이 매우 크고 유효인산함량이 낮은 제주도 화산회토에 있어서 단옥수수 적정인산시비량을 밝히고자 1986년 제주(제주통)와 서귀포(남원통)에서 인산시비량( 0, 8, 16, 24, 32kg/10a)에 따른 단옥수수 교잡종 Golden Cross Bantam 70의 생육 및 수량을 조사한 결과를 요약하면 다음과 같다. 1. 출사일수는 무인산구에서 보다 인산 16kg/10a 이상 시용에 의하여 1～2일 단축되었다. 2. 간장, 착수고, 10a당 생간엽 수량은 두 지역간 유의한 차이가 없었고, 인산시비량이 많을수록 직선적으로 증가하였다. 3. 상품성 있는 이삭의 정균 길이 및 무게는 서귀포에서 보다 제주에서 컸었고, 인산시비량이 많을수록 큰 경향이었다. 4. 주당 또는 10a당 상품성 있는 이삭수, 10a당 이삭수량은 두 지역간 유의한 차이가 없었고, 인산시비량이 많아짐에 따라 이차곡선적인 증가를 보였다. 인산시료와 단옥수수 가격을 고려한 적정인산시비량은 약 26kg/10a로 추정되었다.

• 한국작물학회지
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• 제49권5호
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• pp.373-380
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• 2004

The production of sweet (su) and super sweet corns (sh2) has been economically feasible in Korea in recent years. Major factors limiting super sweet corn production are low germination and low seedling vigor. Since seed quality is closely related to seed maturity, the optimum harvest time for the seed production of sweet and super sweet corns was studied and the quality of seeds with varying maturities was investigated in 2001 and 2002 cropping seasons. The parents of the sweet corn seeds were Hybrid Early Sunglow and 'Golden Cross Bantam 70' and those of super sweet corn were Xtrasweet 82 and 'For­tune'. Seeds were harvested at 21, 28, 35, 42, 49, and 56 days after silking (DAS). As the seeds developed, seed weight of sweet corn increased and the seed moisture content decreased faster than that of super sweet corn. Germination rates of sweet corn seeds harvested 21 and 28 DAS at $25^{\circ}C$ and emergence rates in the cold soil test were significantly lower than those of seeds harvested after 42 DAS in both years. Although the germination rates of super sweet corn seeds with varying maturities showed similar patterns as sweet corn seeds at $25^{\circ}C$, the emergence rate of super sweet corn seeds in cold soil test continuously increased with seed maturity. This suggests that seed quality of super sweet corn should be tested in a cold soil test to estimate field emergence. As the seeds developed, leakage of total sugars and electrolytes from the both sweet and super sweet corn seeds decreased up to 42 or 49 DAS. The $\alpha-amylase$ activities of both sweet and super sweet corn seeds increased with seed maturity from 21 to 35 or 49 DAS depending on genotype and year. The optimum harvest time for the seed production of sweet corn was 42 DAS and 49 DAS for super sweet corn considering emergence rate and plumule dry weight in the cold soil test, leakage of sugars and electrolytes from the seeds, and $\alpha-amylase$ activity.

• 한국작물학회지
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• 제44권3호
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• pp.267-272
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• 1999

In order to determine the optimum harvest time of vegetable corns, the changes in sugars, soluble solids, and flavor of kernels of sweet (cv. ‘Golden Cross Bantam 70’), super sweet (cv. ‘Cocktail E-51’), and waxy corns (cv. ‘Chalok 2’) were observed at different ripening stages. Sucrose was a major sugar in the sweet and super sweet corns and the content increased from 15 to 21 and 27 days after silking (DAS), respectively and then decreased. Glucose and fructose contents of sweet and super sweet corns tended to decrease with kernel maturity. Total sugar content of the sweet corn analyzed by the anthrone method increased rapidly from 15 to 21 DAS, while that of the super sweet and the waxy corns increased slowly up to 24 and 26 DAS, respectively and decreased thereafter. The content of soluble solids in sweet corn was much higher than that of super sweet corn. Starch content of the sweet corn increased slowly from 15 to 33 DAS, while that of the super sweet corn increased a little rapidly from 15 to 21 DAS and then leveled off to 33 DAS. Starch content of the waxy corn increased continuously from 21 to 38 DAS. There was a positive correlation between the sum of individual sugars (sucrose, glucose, and fructose) and soluble solids in both sweet and super sweet corns, while the content of soluble solids was not related to the sum of individual sugars or total sugars. The flavor rate of sweet and super sweet corns maintained high between 21 and 27 DAS and that of waxy corn decreased from 24 to 33 DAS. The optimum harvest time for sweet, super sweet, and waxy corns was thought to be 21 to 24 DAS considering sugar and starch contents, flavor, and marketing.

• 한국작물학회지
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• 제48권5호
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• pp.402-406
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• 2003

Greenhouse and laboratory studies were conducted to determine the allelopathic potentials of extracts or residues from sweet potato (Ipomoea batatas L. (Lam). The extracts applied on filter paper in a Petri dish bioassay significantly inhibited root growth of alfalfa. Aqueous leachates at 40g dry tissue $\textrm{L}^{-1}$ (g $\textrm{L}^{-1}$) from leaves showed the highest inhibition against alfalfa, and followed by stems and roots. Alfalfa root growth was significantly inhibited by methanol extracts of the same plants as the concentration increased. The effect of residue incorporation into soil on seedling growth of com, soybean, barnyard grass and eclipta was examined in the greenhouse, and results showed that the leaf residues at 200g $\textrm{kg}^{-1}$ by plant parts inhibited shoot dry and root dry weights of test plants by 60-80%. By means of HPLC, causative allelopathic substances present in plant parts of sweet potato "Sinyulmi" were identified as coumarin, trans-cinnamic acid, o-coumaric acid, p-coumaric acid, and chlorogenic acid. Total content of these compounds for leaves extracts were detected as the greatest amount in EtOAc fraction, especially trans-cinnamic acid was the greatest component. These results suggest that sweet potato plants have herbicidal potentials, and that their activities exhibit differently depending on plant parts.ant parts.

• 한국작물학회지
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• 제27권4호
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• pp.462-469
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• 1982

Since 1962, varietal development and dissemination for summer upland crops have been actively initiated by the Crop Experiment Station, Office of Rural Development, Suweon, Korea. The major breeding objectives of soybeans have been to develop varieties which are early maturing, disease resistant, and adaptable to late planting for after-barley cropping. Development of eleven new soybean varieties including Hwangkeumkong, Jangyeobkong, Danyeobkong, and Kwangkyo has greatly increased the soybean yield throughout country. For com, after development of Hwangok #2, a synthetic, in early 1960's, nine corn hybrids-single crosses, double-crosses, and three-way crosses-such as Jecheon-ok, Hoengseong-ok, Kwangok, Suweon #19, etc., have been disseminated mainly to Kangweon province, a major corn producing area in Korea, and drew up the yield over 4 tons per hectare. The major breeding objectives of sweet potato have been to develop varieties which have high starch content and root yield. Hwangmi, Hongmi, and Shinmi are three sweet potato varieties developed and disseminated by the Crop Experiment Station, Office of Rural Development and are grown most widely in Korea. Most of researches on cultural practices of upland crops have begun on a full scale from early 1960's. In soybeans, for example, no fertilizer but for barley was applied although the effects of phosphate and potassium fertilizers were great on soybeans in after-barley soybean croppings. The effects of heavy application of phosphate and calcium fertilizers on soybeans in newly reclaimed soils were recognized. Recently a mixed fertilizer for soybean (N; 40, P:70, K:60 kg/㏊) was developed and sold for soybean growers. The optimum planting densities of 220, 000 plants/ha in full-season cropping and 330, 000 pts/ha in after-barley cropping of soybeans were known from repeated experiments. For higher yield, a means of cultural practices such as transplanting-pinching, direct planting-pinching, and hilling-up, etc., were developed along with barley-stubble planting with no tillage and integrated herbicide application for labour savings. For sweet potato, cultural practices for planting date, harvesting date, fertilizer, and planting density were fully established. For early marketing, a technique of vinyl-mulching on sweet potato has also fully developed. For com, planting density of 37, 000 pts/ha in early 1960's has been changed to 55, 000 pts/ha for grain production and 67, 000 pts/ha for silage. The amounts of fertilizers have also been changed from 120-120-120kg/ha (N-P-K) in early 1960s to 180-150-150 kg/ha. These increases in number of plants per unit area and fertilizer levels have resulted in greater production for both grain and silage. At the same time, the production techniques of F1 seeds have also improved.

• 한국작물학회지
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• 제53권1호
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• pp.42-49
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• 2008

흑색 P E. film 피복과 노지재배에서 초당옥수수를 원하는 시기에 수확할 수 있는 파종기를 결정하는 방법을 찾기 위하여 "Cambella-90"을 4월 1일에서 6월 30일까지 10일 간격으로 파종한 후 파종기와 관계없이 파종에서 수확까지 생육기간을 일정하게 나타낼 수 있는 GDD 모델과 기준온도를 설정하였으며, 그 결과를 요약하면 다음과 같다. 1, 초당옥수수의 생육기간은 파종기에 따라 흑색 P. E. film 피복에서는 $64{\sim}93$일, 노지에서는 $66{\sim}97$일로 파종기간 CV는 각각 13.8 및 14.2%이었다. 그러나 생육기간을 GDD로 표시하면 최적 기준온도를 적용하였을 때 파종기간 GDD의 CV는 모델에 따라 흑색 P. E. film 피복에서는 $1.1{\sim}2.4%$, 노지에서는 $1.5{\sim}1.8%$이었다. 2. 초당옥수수의 생육기간을 나타내는 가장 적합한 GDD 모델은 파종에서 수확까지 일 최고기온과 최저기온을 합하여 2로 나눈 후 기준온도를 빼서 GDD를 계산하되 일 최고 기온이 $30^{\circ}C$가 넘을 때는 일 최고기온에서 $30^{\circ}C$를 넘는 만큼 $30^{\circ}C$에서 빼어 그 값을 최고기온으로 대치하고, 최저기온이 기준온도 이하일 때는 기준온도로 대치하여 계산하는 방법이었다. 이때 기준온도는 흑색 P. E. film 피복에서는 $9^{\circ}C$, 노지재배에서는 $10^{\circ}C$이었다. 3. 원하는 시기에 수확하기 위한 파종기를 결정하기 위해서는 그 지역의 누적 GDD표를 만들고, 수확 예정일의 누적 GDD에서 그 품종의 GDD를 빼서 그 GDD에 해당되는 일자를 선택하면 된다.

• 한국식품영양학회지
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• 제12권5호
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• pp.513-517
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• 1999

Theessential oils of anise darkopal lettuce and sweet basils cultivated in Korea were extracted by simulatneous steam distillation and extraction method and were analyzed by GC/MSD. Total 41 com-ponents were identified in essential oils including 11 alcohols, 6 carbonyls 19 hydrocarbons and 5 esters components. The major components were 1,8-cineole linalool $\alpha$-bergamotene $\beta$-elemene methyl chavicol, $\beta$-cubebene methyl cinnamate and eugenol. Darkopal lettuce and sweet basils were rich in linalool(30.1-36.5%) methyl chavicol(8.1-25.5%) and relatively poor in methyl cinnamate(0-2.71%) Anise basil was rich in linalool(28.5%) and methyl cinnamate(23.1%) However methyl chavicol which was known as one of the main components of bisil was not detected.