• 농업과학연구
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• 제45권3호
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• pp.355-363
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• 2018

This study was conducted to investigate suitable rice cultivars for various rice based cropping systems in a paddy field in the Yeongnam plain area. Thirteen rice cultivars (5 early, 3 medium and 5 mid-late maturing cultivars) and three transplanting dates (June 5, June 25 and July 5) were evaluated in this study. The mid-late and early maturing cultivars for the July 5 and June 25 transplanting headed before August 30 which is the safe heading date in the Yeongnam plain area, ranging from Aug. 26 - 28 and Aug. 18 - 23, respectively. The safe harvest time of rice for double and triple cropping systems should be before the middle of October for the cultivation of the succeeding winter crops. The rice yield was the highest for the June 5 transplanting regardless of the rice cultivars, and it gradually decreased as the transplanting date was delayed from June 5 to July 5 due to a decrease in the spikelet numbers per panicle number and in the ripened grain rate. In contrast, the other yield parameters that include the panicle number per $m^2$, the 1,000-brown rice weight, and the ripened grain ratio were not significantly affected. The result indicates that based on the milled rice, heading time and harvest time, a medium maturing cultivar (Haiami and Samdeog) would be applicable to a winter barley/wheat, garlic/onion-summer rice double cropping, while a mid-late cultivar (Saeilmi, Saenuri and Hyunpoom) would be suitable for a spring potato/waxy corn-summer rice double cropping in the Yeongnam plain area. On the other hand, an early maturing cultivar (Unkwang, Jokwang and Haedamssal) would be preferable for a triple cropping because of the short growth period of rice.

• 한국작물학회지
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• 제50권5호
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• pp.309-318
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• 2005

Higher level of KCl application stimulated both leaf area index and leaf area duration in all cassava varieties, while the leaf and tuber number of the bitter varieties (high cyanide-level varieties) decreased in proportion to the level of KCl application. The root/shoot (R/S) ratio and harvest index (HI) were negatively related with the level of KCl application in all cassava varieties. The bitter varieties obtained the lowest R/S ratio at the level of 100 - 150 kg KCl $ha^{-1}$, while the sweet varieties (low cyanide-level varieties) acquired the highest values at the level of 50 - 150 kg KCl $ha^{-1}$. Also, the sweet varieties showed the lowest HI at the level of 250 kg KCl $ha^{-1}$, but the bitter varieties at the level of 150 kg KCl $ha^{-1}$. At 6 - 8 months after planting, the sweet varieties tended to obtain higher starch content of roots (tubers) at the level of 50 - 150 kg KCl $ha^{-1}$, while the bitter varieties at the level of 150 - 250 kg KCl $ha^{-1}$. Relatively lower level of 50 - 150 kg KCl $ha^{-1}$ was more appropriate for decreasing hydrocyanic acid (HCN) content of roots (tubers) in the sweet varieties at the harvest time, and the level of 250 kg KCl $ha^{-1}$ was adequate to decrease not only HCN content of leaves but also that of roots (tubers) in the bitter varieties during the growing period. To obtain higher yield and starch content of tubers, and lower HCN content of roots (tubers), it was recommended that the sweet varieties are applied with the level of 50 - 100 kg KCl $ha^{-1}$ and the bitter varieties with the level of 150 - 200 kg KCl $ha^{-1}$, respectively, in Latosol soils of Bogor areas, West Java.

• 한국잡초학회지
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• 제32권1호
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• pp.17-24
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• 2012

The study was conducted to investigate the effect of weed interference and starter fertilizer on subsequent soybean seed quality at the Agricultural Research Farm and Laboratory of Razi University, Kermanshah, Iran. Two factorial experiment was laid-outon a randomized complete block design with four replications. First factor was starter fertilizer levels (0 and 25 kg $ha^{-1}$) applied in the forms of monoammonium phosphate, the second factor was different weed interference periods consisted of five initial weed-free periods (in which, plots were kept free of weeds for 0, 15, 30, 45 and 60 days after crop emergence (DAE) and then weeds were allowed to grow until harvest) and five initial weed-infested periods (in which, weeds were allowed to grow for 0, 15, 30, 45 and 60DAE, after which the plots were kept free of weeds until harvest). Full season weedy condition reduced 100-seed weight, seed germination percentage and seedling dry weight by 25.9, 13.3 and 22.5%, respectively and increased mean germination time and seed electrical conductivity by 55.8 and 24.3%, respectively as compared with full season weed-free control. However, the traits under study were not significantly influenced when field was kept free of weeds for at least 45 DAE (R1) or weedy condition was continued for less than 30 DAE (V8). There was a significant and negative correlation between weed biomass and seed weight (r = -0.93), so that when weed free condition was less than 45 DAE or weed infested period was continued for at least 30 DAE, soybean plants produced wrinkled and underdeveloped seeds with lower weights and qualities. Moreover, soybean seed quality reduction due to weed interference was more evident when starter fertilizer was applied and weeds interfered with soybean from the beginning of the growing season. Information from the present study is beneficial in soybean seed production systems and where farmers use the harvested seeds for the following planting.

• 농업과학연구
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• 제38권3호
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• pp.405-411
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• 2011

In this study, we evaluated the changes of fruit quality indices during fruit development and ripening in Korean new pear cultivar 'Wonhwang' and 'Whasan' to determine appropriate harvest time and to enhance the marketability. The fruit of each cultivar harvested from 100 days after full bloom (DAFB) to 135 and 150 DAFB in 'Wonhwang' and 'Whasan', respectively. The fruit growth of both cultivars showed a typical single sigmoidal pattern. Flesh firmness of two cultivars decreased continuously with fruit development and ripening, reaching a final level of about 2.6 kgF at harvest stage. The starch content of fruit sap was much higher in the fruits of early development stage than the later stage of fruit ripening. In 'Wonhwang' pears, the starch level decreased coincide with fruit ripening (130 DAFB), while that of 'Whasan' decreased from very early stage of fruit development (120 DAFB), 30 days before full ripe. 'Whasan' pear showed much lower acidity level of about 0.13% during fruit development and ripening period compared with that of 'Wonhwang'. Therefore, the ratio of soluble solids to total acidity (TSS/acid) increased gradually with fruit development and ripening, reaching a final level of 80 and 98 in 'Wonhwang' and 'Whasan', respectively. There were no climateric rise of fruit respiration during fruit ripening periods in two oriental pear cultivar. The changes of skin color difference including hunter vale $a^*$ which means loss of green color occurred only after onset of ripening in two cultivars.

• 한국작물학회지
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• 제40권6호
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• pp.705-710
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• 1995

맥주보리의 수확기에 강우가 많았던 제주산 강우피해보리 와 기상상태가 양호하였던 전남, 경남산의 맥주보리의 발아성을 비교하여, 생산된 맥주보리의 사용을 원활하게 할 수 있는 방안을 강구하고자 종자의 병원균 감염여부와 수발아성을 확인하고 아울러 휴면정도와 발아성을 조사한 결과 수확기의 강우는 발아에 지장을 초래하여 '91년산의 제주산은 46∼71%의 수준으로 불량하였다. 발아율이 낮은 제주산도 발아에 지장을 줄 정도의 병감염은 없었다. 강우피해보리는 포도당과 맥아당의 함량이 높았는데, 이는 곡립의 물질분해가 이루어진 것으로 보여지며 수발아현상으로 추정되었다. 제주산 강우피해보리에서 수발이후 휴면하는 종자가 많음을 TZ발아능 예측검사에서 알 수 있었으며 강우피해보리의 경우 저온발아시험에서 발아율이 높으므로 보아 2차휴면을 하고 있음을 알 수 있었다. 수확후 12개월간 저장한 후에는 발아력이 향상됨을 알 수 있었다. 이와 같은 현상으로 보아 발아불량은 2차휴면의 결과로 보이며, 월동에 의한 저온처리후에 원료로 사용하거나 수확 직후에 발아력이 50%이상일 경우에는 5 에서 5일간 함수상태 예냉처리로, 발아력이 50%이하로 낮은 경우에는 gibberellic acid 1ppm수준으로 처리하면 발아율을 증대시킬 수 있을 것으로 본다. 발아력과 휴면정도가 다양한 seed lot을 재료로 맥주보리의 발아력향상에 관한 예냉과 gibberellic acid 처리의 효과를 재 구명할 필요가 있겠다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.332-332
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• 2017

Rice ratooning is the cultural practices to produce easily second rice from the stubble left behind after the main-crop harvest. The main advantage of rice ratooning is that in areas where rice is the main crop, double crop of rice can be grown for additional returns. Three early ripened rice cultivars were tested for estimation their milled rice quality and starch characteristics from main and ratoon rice. The main crop was harvested at mass maturity, after which the tillers were mowed to stubbles of about 10 cm tall. And then it left without any further input until the ratooned plant was ready for harvest. Highly significant variations were detected in the milled rice quality between main and ratoon rice. Protein and amylose contents of ratoon rice were more increased than those of main rice. The Toyo value (gloss) of cooked rice of ratoon crop was measured also higher than that of main crop. It resulted from higher air temperature during grain ripening compared with that of ratoon crop. The mean temperature during ripened period of ratoon rice was favorable for optimal maturation for early ripened rice cultivars. Normalized chromatograms of branch chain length distribution of amylopectin are demonstrated a distinct difference between main and ratoon rice flour. Ratoon rice had higher amount of short chains than that of main crop rice starches. Microscopic examination of rice flours with scanning electron microscopy shows starch granule shapes affected by the cropping types, main and ratoon rice. It showed significant differences among rice starch granule shapes and in granule size between main and ratoon rice. Starch of ratoon rice had more neat and smaller granules than that of main rice.

• 한국지역사회생활과학회지
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• 제17권1호
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• pp.101-108
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• 2006

This study was conducted to develop the regulating methods for the optimal harvest stage of new sprout for woody plants, and to clarify the effects of storage condition and period on the growth of new sprout formed of Aralia elata cv. 'Jeongkwang'. Japanese angelica tree were collected in the Jangheung district of Jeonnam on 20. March, 2005, and those cut branches were stored at $5{\pm}2^{\circ}C$ and 80 to 90% of the relative humidity, and were cut in water. Survival rate of cut branches for Aralia elata cv. 'Jeongkwang' was significantly increased when that was used for the cutting after the collection with no storage. And those survival rate was much more increased when that was stored at 80 to 90% of relative humidity than 40 to 50% of relative humidity. Number of new sprouts formed which were not stored immediately after the collection 3.2 to 3.4, and that were stored at cold storage room before cutting and cut on 1. June and 1. August were 5.1 to 5.3. Leaf growth of cut branches cut in water on 20. March started at ten days after cutting, and that on 1. June and 1. August at one to two days after cutting. Slow and mature sprout growth of Aralia elata cv. 'Jeongkwang' which were cut in water were different by the cold storage periods. Nineteen days were needed for the mature growth of sprout when cut in water on 20. March, and thirteen days on 1. August.

• 한국초지조사료학회지
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• 제16권4호
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• pp.315-326
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• 1996

An experiment was carried out to determine effect of cultivar, drying agent concentration and preservative on the moisture content, temperature and quality changes of fall harvested oat(Avena sativa L.) hay during field curing and storage. The main plots consisted of the cultivar such as 'Foothill' and 'Swan', the subplots consisted of drying agent concentration such as 7Skg/ha(C1), lOSkglha(C2) and control(C0) and the sub-subplots consisted of preservative such as buffered acid(BA), lactic bacteria inoculant(LB) and control(C0). Moisture contents of 'Foothill' and 'Swan' oat cultivar at harvest were 635.5 and 385.4%DW(Dry weight), respectively, but the final moisture contents of the oat cultivars were 117 and 86%DW. The moisture content of cut oat was not affeded by drying agent concentration. Core temperature of baled 'Swan' oat hay was a little higher than that of 'Foothill' and no consistent preservative effect was found. Total nitrogen content of 'Swan' oat hay was 3.08% and that of 'Foothill' oat hay was 3.45%(P<0.05). Drying agent treatment increased total nitrogen content of 'Swan'(P <0.05), but preservative had no effect. Crude fiber content of oat cultivar was increased as the curing progressed(P<0.05) and the difference of crude fiber content of oat cultivar was maintained through the whole curing period. Effect of drying agent concentration on crude fiber content was not found after preservation. Crude fiber content of 'Swan' oat hay was higher than that of 'Foothill' by 1.O% in ADF and 3.1 % in NDF(P<0.05). No preservative effect was found in crude fiber content. According to RFV of oat cultivar at harvest, forage quality of 'Foothill' and 'Swan' was Prime and Grade 1, respectively, but that of both cultivm was above Grade 2 at the final curing day. RFV of the stored 'Foothill' and 'Swan' oat hay was 122 and 114(P<0.05), respectively, and the quality of oat hay was classified as Grade 1 and 2, respectively, according to the forage quality standard assigned by AFGC.

• 한국식품과학회지
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• 제26권5호
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• pp.512-519
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• 1994

박하를 대상으로 재배조건 및 수확시기에 빠른 방향 성분의 함량변화를 조사한 결과 박하의 생육은 비닐보온시험구에서 초기에 왕성한 생육을 보였지만, 수확기가 가까와 짐에 따라 다른 시험구와 유사하게 성장하였으며, 강유량과 일조시간에 따라 줄기와 잎의 성장속도에서 매우 많은 차이를 보였다. 수확시기에 따른 조성분의 변화는 l-menthone의 l-menthol로의 환원과정이 일조시간의 차이에 따라 그 진행속도가 빨라졌으며, 수확말기에 가서는 특히 menthofuran의 함량이 급속히 증가하는 현상을 보였다. 따라서 전체적으로 정유 조성분의 비율이 가장 양호한 시험구는 7월 5일과 7월 7일 수확분으로서, 이 시기가 수확 적기임을 알 수 있었고 정유의 우율도 이 시기에 가장 높게 확인되었다.

• 한국약용작물학회지
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• 제23권1호
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• pp.8-12
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• 2015

Characteristic of seed for Sageretia thea fruits collected from the habitat of harvest season in Jeju and their germination ratio in different temperatures were considered. The average weight was 0.2 g, average diameter was 7.2 mm, average length was 6.5 mm, and size distribution range was 5.1 ~ 10.0 mm. The number of seeds per fruit was 1.8, and 1000 grain weight was 7.77 g with diameter of 3.7 mm and thickness of 1.7 mm in size. The fruit maturation was investigated to be from April 27 to June 1, when the best maturation period was about a week, May 11 to May 18. Also, the fruits grown on May 4 to May 11 were seen to have the bigger in transverse size and weight with a tendency of the earlier maturation date has the greater the number of seeds. S. thea seeds pretreated for 24 hours at $50^{\circ}C$ were not germinated, while most of those pretreated for 24 hours at $4^{\circ}C$ were successfully germinated at any degree of temperature (except at a temperature of $10^{\circ}C$). Particularly, the highest germination rate of 55% was made at $15^{\circ}C$, and plumule and radicle were best grown within the temperature range of $25^{\circ}C$.