According to numerous chamber and free-air CO2 enrichment (FACE) studies with artificially raised CO2 concentration and/or temperature, it appears that increasing atmospheric CO2 concentrations ([CO2]) stimulates crop yield. However, there is still controversy about the extent of the yield stimulation by elevating [CO2] and concern regarding the potential adverse effects when temperature rises concomitantly. Here, we tested the effects of natural elevated [CO2] (ca. 120 ppm above the ambient level in 100 years ago) and warming (ca. 1.7–3.2 °C above the ambient level 100 years ago) on rice growth and yield over three crop seasons via a past reference investigation and current experiment (PRICE) study. In 2020–2022, the rice cultivar Tamanishiki (Oryza sativa, ssp. japonica) was grown in Wagner’s pots (1/2000 a) at the experiment fields of Chonnam National University (35°10′ N, 126°53′ E), Gwangju, Korea, according to the pot trial methodology of the reference experiment conducted in 1920–1922. Elevated [CO2] and temperature over the last 100 years significantly stimulated plant height (13.4% on average), tiller number (11.5%), and shoot biomass (10.8%). In addition, elevated [CO2] and warming resulted in a marked acceleration of flowering phenology (6.8% or 5.1 days), potentially leading to adverse effects on tiller number and grain yield. While the harvest index exhibited a dramatic reduction (12.2%), grain yield remained unchanged with elevated [CO2] and warming over the last century. The response of these crop parameters to elevated [CO2] and warming was highly sensitive to sunshine duration during the period from transplanting to heading. Despite the pot-based observations, considering a piecewise response pattern of C3 crop productivity to [CO2] of <500 ppm, our observations demonstrate realistic responses of rice crops to elevated [CO2] (+120 ppm) and moderate warming (+1.7–3.2 °C) in the absence of adaptation measures (e.g., cultivars and agronomic management practices). Hence, our results suggest that the PRICE platform may provide a promising way to better understand and forecast the net impact of climate change on major crops that have historical and experimental archived data, like rice, wheat, and soybean.

A cowpea cultivar ‘Okdang’ ( Vigna unguiculata L. Walp) was developed by the Jeollanamdo Agricultural Research and Extension Services (JARES) in 2013 using the breeding method of pure line isolation applied to the foundation stock of IT45384. ‘Okdang’ has an erect plant type with an intermediate plant habit, green hypocotyls, heart leaflet, orange yellow seed surface of faint luster, and brown and straight pods when matured. Its first flowering and maturing dates were approximately seven and ten days earlier than that of the control cultivar ‘Seoweon’. The stem length of ‘Okdang’ was 42 cm, which was 57 cm shorter than that of the control cultivar. Its 100-seed weight was 16.6 g, which was heavier than that of the control cultivar by 5.9 g. The weight ratio of the seed coat for the entire seed was 12%, which was 1.4%p lower than that of the control cultivar. Its field resistance to leaf and systemic diseases was as strong, or slightly weaker than that of the control cultivar. In addition, ‘Okdang’ had a high lodging resistance. The average yield of ‘Okdang’ was 1.85 ton/ha, which was 40% higher than that of the control cultivar ‘Seoweon’ (Cultivar registration number: 5879).

사과, 배, 복숭아, 포도 등을 재배하는 과수원에 발생하는 잡초를 조사하여 과수원 문제잡초의 현황을 파악하고 잡초방제의 기초자료로 활용하기 위하여 2015년에 전국을 11개 권역으로 나누어 실시하였다. 과수원에 발생하는 잡초는 63과 492종으로 국화과 86종, 화본과 63종, 두과 29종, 사초과 23종, 마디풀과 22종 등의 순이었다. 이들 잡초를 생활형으로 구분하면, 일년생 159종, 동계 일년생 97종, 다년생 236종이었다. 과수원별 발생잡초를 보면, 사과밭에는 50과 306종, 배밭에는 50과 304종, 포도밭에는 50과 286종, 복숭아밭에는 48과 288종이 발생되었다. 우점잡초로는 바랭이, 쑥, 쇠별꽃, 닭의장풀, 깨풀 등이었다. 외래잡초는 127종으로 전체의 25.8%이었고, 토끼풀, 망초, 흰명아주, 서양민들레, 소리쟁이 순으로 발생이 많았다. 30년간의 잡초군락 변화를 보면, 1990년에는 바랭이, 여뀌, 쇠비름 등이 우점하였으나, 2003년에는 바랭이, 깨풀, 쑥 등으로 변하였다. 2015년에는 바랭이, 쑥, 쇠별꽃 등으로 크게 변하지는 않았다. This study was investigated in order to occurrence of weed flora in orchard (apple, grape, peach, pear etc.) fields and to the establishment of weed control basic data in these weeds. And this study was survey on 2015. As a result of the study on orchard weeds, there were total of 492 weeds including 63 families. Among all the weeds, 159 species were annual, 97 species were winter annual and 236 were perennial. Each fruit tree patterns of occurrence weeds, 306 species 50 families in apple orchard, 304 species 50 families in pear orchard, 286 species 50 families in grape orchard, and 288 species 48 families in peach orchard. Dominance was the highest with Digitaria ciliaris followed by Artemisia princeps, Stellaria aquatica, Commelina communis, Acalypha australis etc. in order. And exotics weeds occurred 127 species. Trifolium repens was the highest in importance analysis and the followings were in order of Conyza canadensis, Chenopodium album, Taraxacum offcinale, Rumex crispus etc. Changes in weed vegetation in orchard during 30 years, did not very many changed. In 1990, D. ciliaris, Persicaria hydropiper, Portulaca loeracea were dominant. In 2003, D. ciliaris was the most abundant species, followed by A. australis, A. princeps species. And in 2015, also D. ciliaris was the most dominant, followed by A. princeps, S. aquatica.

The nationwide weed survey was conducted in arable land, paddy field, upland, orchard and pasture, over whole country of Korea during 3 years from 2013 to 2015. Also, these survey were conducted in order to determine a change of weed community and to identify a major dominant weed species, and problem weeds. Weeds of arable land were composed of 619 species belonging to 81 families. Weeds occurred in paddy field were 90 species belonging to 28 families, upland weeds were 375 species of 50 families, orchard weeds were 492 species of 63 families and pasture weeds 275 species of 52 families. Among total 81 families, the Asteraceae (15.5%) was the biggest family, followed by Poaceae (13.1%), Fabaceae (5.5%), Cyperaceae (5.2%), Polygonaceae (6.3%), respectively. And these weed species were composed of annual weeds of 209 species (33.8%), winter annual of 102 species (16.4%) and perennial weeds of 308 species (49.8%). Exotic weeds naturalized in Korea were investigated as 166 species. Weed flora in Korean cultivation area have been increased as much as 13 families and 186 species for 10 years compared to 2000~2004 weed survey result of 68 families and 433 species. The increment could be resulted from the change of weed population such as increase of the herbicide-resistant and the difference of investigation method.

우리나라 논에는 28과 90종의 논잡초가 발생하고 있다. 이것을 8개 지역별, 19개 농업기후지대별로 구분하여 잡초방제의 기초자료로 활용하고자 한다. 경기지역에는 20과 52종, 강원지역은 17과 37종. 충북지역은 15과 41종, 충남지역은 12과 21종, 전북지역은 13과 24종, 전남지역은 21과 54종, 경북지역은 20과 36종, 경남지역은 16과 32종이 발생하였다. 과별로 보면, 화본과 > 방동사니과 > 국화과 등으로 순이었고, 지역간에 차이는 있지만 대체로 피속류, 물달개비, 올챙이고랭이, 올방개, 벗풀 등이 우점하였다. 태백준고냉지대에서 14과 31종부터 동해안남부지대의 16과 25종까지 18개(태백고냉지대 제외) 기후지대별로 논에 발생하는 잡초는 다소 차이는 있지만, 피속류, 물달개비, 올챙이고랭이 순으로 발생되었다. 과별로는 방동사니과 > 화본과 > 국화과 등의 순으로 우점하였다. 지역별 및 기후지대별 잡초발생 상황의 차이는 지역적인 개념보다 여러 가지 기상요건에 의한 것이 크게 좌우되었고, 거기에 수반되는 재배양식 변화 그리고 제초제 사용에 따라 차이가 있을 것으로 판단되었다. Ninety species belonging to 28 families of weeds were identified in Korean rice fields. They were divided by eight provinces and 19 agro-climatic zones to be used as basic data of weed control. Looking at the regional weed occurrence, there were 52 species of 20 families in Gyeonggi, 37 species of 17 families in Gangwon, 41 species of 15 families in Chungbuk, 21 species of 12 families in Chungnam, 24 species of 13 families in Jeonbuk, 54 species of 21 families in Chonnam, 36 species of 20 families in Gyeongbuk, and 32 species of 16 families in Gyeongnam province, respectively. The most dominant family was Poaceae followed by Cyperaceae and Asteraceae. Mostly dominant species were Echinochloa spp., Monochoria vaginalis var. plantaginea, Scirpus juncoides var. hotarui, Eleocharis kuroguwai, and Sagittaria sagittifolia subsp. leucopetala with slight differences among the provinces. Although there were some differences in 18 climate zones from Taebaek sub-highlands to the southern part of the East Coast (except for the Taebaek Highland), the dominant species were Echinochloa spp., Monochoria vaginalis var. plantaginea and Scirpus juncoides var. hotarui. The most dominant family was Cyperaceae followed by Poaceae and Asteraceae. The differences of weed occurrence between provinces and agro-climatic zones were largely influenced by various weather conditions rather than the provinces. The changes in cultivation mode and herbicide use might influence as well.

우리나라 밭에 발생하는 잡초를 조사하여 각 작목별 문제잡초의 현황을 파악하고 잡초방제의 기초자료로 활용하기 위하여 2014년 4~5월 및 7~8월에 2회 실시하였다. 밭에 발생하는 잡초는 총 50과 375종으로 국화과 73종, 화본과 44종, 마디풀과 25종, 십자화과 21종, 콩과 20종 등의 순이었다. 이들 잡초를 생활형으로 구분하면, 일년생 162종, 월년생 78종, 다년생 135종이었다. 보리, 마늘, 양파 등 동계작물 재배지에는 45과 287종, 고추, 콩, 옥수수 등 하계작물 재배지에는 47과 339종이 발생되었다. 우점도별 상위 10초종은 바랭이, 쇠비름, 깨풀, 흰명아주, 속속이풀, 돌피, 한련초, 중대가리풀, 냉이, 참방동사니 순이었다. 외래잡초는 25과 129종으로 흰명아주, 개비름, 망초, 좀명아주, 미국가막사리, 털별꽃아재비 등이었다. 밭잡초 발생정보는 향후 잡초발생 예측, 잡초군락 변화 그리고 밭잡초 방제의 기초자료로 유용하게 사용될 수 있을 것이다. Surveys of weed species on upland fields were conducted in Korea to investigate the occurrence of weed flora from April to May 2014 for winter crop fields and from July to August 2014 for summer crop fields. From the nation-wide survey, 375 weed species in 50 families were identified and classified to 162 annuals, 78 biennials and 135 perennials. Based on the occurrence ratio, the most weed species belonged to Compositae (73 species). 44 and 25 weed species belonged to Poaceae and Polygonaceae, respectively, and these 183 weed species in the most five families accounted for 49% of total weed occurrence. While 287 weed species in 45 families occurred in the winter crop fields, 339 weed species in 47 families occurred in summer crop fields. The most dominant weed species in Korean upland fields were Digitaria ciliaris, followed by Portulaca oleracea, Acalypha australis, Chenopodium album, Rorippa palustris etc. 129 weed species in 25 families were considered as exotic weeds. Based on the importance analysis, the highest value was C. album followed by Amaranthus lividus, Conyza canadensis etc. This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in upland fields of Korea.

본 연구는 전국 논의 재배양식별 잡초 분포현황을 알아보기 위하여 2013년 6월부터 9월까지 도 농업기술원, 농업 대학 및 관련 연구소 등 11개 기관에서 전국 8도 155개 시 군의 3,434지점에서 잡초분포조사를 수행하였다. 조사결과 2013년 현재 우리나라 논에는 일년생잡초가 52종, 월년생잡초 3종, 다년생잡초 35종을 포함한 28과 90종의 잡초가 발생하는 것으로 확인되었다. 발생한 잡초의 과별구성을 보면 화본과 18종, 사초과 17종, 현삼과 8종 마디풀과 6종 순으로 상위 4개 과가 포함하는 49종이 전체의 54%를 차지하였다. 조사된 잡초는 피 17.4%, 물달개비 12.4%, 올방개 7.8%, 올챙이고랭이 6.2%, 벗풀 6.1% 순으로 우점하였다. 이번 연구결과를 이용하여 앞으로 전국 논잡초의 발생양상을 예측하며 잡초군락의 변화를 파악함으로써 체계적인 논잡초 관리방안을 마련할 수 있을 것으로 판단된다. Surveys of weed species in paddy fields were conducted in Korea to identify weed occurrence from June to September 2013. Total 3,434 sites of paddy fields in 155 City/Gun, eight Provinces were investigated. From the nation-wide survey, 90 weed species in 28 families were identified and classified to 52 annuals, 3 biennials and 35 perennials. Based on the occurrence ratio, the most weed species belonged to Poaceae (18 species). 17, 8 and 6 weed species belonged to Cyperaceae, Scrophulariaceae and Polygonaceae, respectively, and these 49 weed species in the most four families accounted for 54% of total weed occurrence. The most dominant weed species in Korean paddy fields were Echinochloa spp. (17.4%), followed by Monochoria vaginalis (12.4%), Eleocharis kuroguwai (7.8%), Bidens tripartite (9.27%), Scirpus juncoides (6.2%) and Sagittaria sagittifolia (6.1%). This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in paddy fields of Korea.

The purpose of this study was to establish the proper sowing time and planting density of cowpeas for labor-saving cultivation. Experiments were carried out in Naju, Jeonnam Province (Latitude 04` N, Longitude 54` E) during 2012 and 2013. The intermediate-erect type strains used in this study were Jeonnam1 and Jeonnam2. Sowing was performed five times between June 25 and August 5 at approximately 10-day intervals in order to establish proper sowing time, and sowed at 5,000, 10,000, 15,000, and 20,000 plants per 10a to establish proper planting density. The days from sowing to first flowering was shortest (32 days) in plants sowed on July 25 and became longer for plants sowed on or around July 25. The days from sowing to first flowering was longest (41 days) in plants sowed on June 25. The days from first flowering to first maturing was shortest (8 days) in plants sowed on June 25 and, became considerably longer at later sowing dates. The days from first maturing to first harvesting ranged from 8 to 10 days, with little difference among the sowing periods. Plants sowed on August 5 harvested at the same time, and plants sowed between June 25 and July 25 were harvested either three or two times. The yield was highest in plants sowed on July 25: 209 kg/10a was harvested for Jeonnam1 and 221 kg/10a for Jeonnam2. Furthermore, harvested at the same time enabled when the harvesting was delayed for around 15 days because the share of the seeds first harvested was highest (91%). The proper planting density was estimated to be 15,000 plants/10a, showing the highest yields of 199 kg/10a for Jeonnam1 and 224 kg/10a for Jeonnam2.

본 연구는 남부지역에서 주요 콩 품종의 파종기 이동이 isoflavone 등 생리활성물질에 미치는 영향을 구명하고자 전남 나주(위도 $35^{\circ}$ 04'N, 경도 $126^{\circ}$ 54'E)에서 2008년부터 2010년까지 3년간 수행되었다. 여름형콩 품종인 새올콩과 다원콩, 가을형콩 품종인 태광콩, 풍산나물콩 및 청자3호를 이용하여 파종기를 5월 15일, 5월 30일, 6월 15일, 6월 30일, 7월 15일에 실시하였으며, 주요 결과를 요약하면 다음과 같다. 1. Daidzein 함량은 모든 시험품종에서 genistein과 total isoflavone 함량은 청자3호를 제외한 시험품종에서 파종이 늦어질수록 증가하는 경향이었다. 반면에 glycitein 함량은 다원콩을 제외한 시험품종에서 파종기간 유의차가 없었다. 2. Cyanidin-3-glucoside(C3G) 함량은 다원콩과 청자3호, delphinidin-3-glucoside(D3G)와 total anthocyanin 함량은 다원콩에서만 파종이 늦어질수록 유의하게 증가하였다. 그러나 pelargonidin-3-glucoside(Pg3G)와 petunidin-3-glucoside(Pt3G) 함량은 파종기간 유의차가 없었다. 3. 청자3호의 lutein 함량은 파종기에 따라 $2.7{\sim}3.0{\mu}g/g$로 유의차가 없었고, chlorophyll 함량은 파종이 늦어짐에 따라 증가하여 6월 30일과 7월 15일 파종에서 유의하게 많았다. 4. 조지방 함량은 태광콩과 청자3호는 조기에 파종할 때 많았고 기타 시험품종은 파종기간 유의차가 없었다. Palmitic acid 조성비는 대부분 시험품종에서 파종기의 영향을 받지 않았다. Stearic acid 조성비는 새올콩, 다원콩, 청자3호에서 파종이 늦을수록 증가하였다. Oleic acid, linoleic acid 조성비는 새올콩에서만 파종기가 빠를수록 유의하게 높았다. Linolenic acid 조성비는 대부분 시험품종에서는 파종이 늦을수록 유의하게 증가하였다. 5. 파종기 이동에 따른 탄수화물과 조단백질 함량은 대부분 시험품종에서 유의차가 없었다. 그러나 새올콩은 조기에 파종할수록, 다원콩은 만기에 파종할수록 조단백질 함량이 많은 경향이었다. The purpose of this study was to investigate the effects of sowing time on the bio-active content of major soybean cultivars in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (latitude $35^{\circ}$ 04'N, longitude $126^{\circ}$ 54'E) from 2008 to 2010. The cultivars grown in summer included Saeol-kong and Tawon-kong and those grown in autumn included Taekwang-kong, Pungsannamul-kong, and Cheongja3, respectively. Sowing dates were May 15 and 30, June 15 and 30, and July 15 of each year. Daidzein content was increased in all the test cultivars grown from later sowing, and the contents of genistein and total isoflavone were increased in all the test cultivars except for Cheongja3. On the other hand, glycitein content showed no significant change in any of the test cultivars across the 5 sowing dates except for Tawon-kong. Cyanidin-3-glucoside (C3G) content was significantly increased in Tawon-kong and Cheongja3, and delphinidin-3-glucoside (D3G) and total anthocyanin contents were significantly increased in Tawon-kong. However, pelargonidin-3-glucoside (Pg3G) and petunidin-3-glucoside (Pt3G) contents showed no significant difference in plants sown across the 5 dates. Lutein content in Cheongja3 was between 2.7 and $3.0{\mu}g/g$ based on sowing date and did not vary significantly, while chlorophyll content increased with later sowing and was significantly higher in the cultivars sown on June 30 and July 15. Crude fat content was higher in Taekwang-kong and Cheongja3 when the cultivars were sown earlier; crude fat did not vary in the other test cultivars based on sowing date. Palmitic acid composition was not affected by sowing date in most of the test cultivars. Stearic acid was increased in Saeol-kong, Tawon-kong, and Cheongja3 with later sowing. Oleic acid and linoleic acid were significantly higher in Saeol-kong at an earlier sowing date. The composition of linolenic acid showed significantly increased dates in most of the test cultivars with later sowing. There were no significant differences in carbohydrate and crude protein content across 5 different sowing dates in most of the test cultivars. However, crude protein content was higher in Saeol-kong when sowing occurred earlier, and was higher in Tawon-kong at later sowing dates.

Despite the growing body of evidence that ongoing warming modifies the cereal quality of several crop species, little is known about how it interacts with other climate change drivers. Here, we examined how elevated [CO2], warming, and extreme wet events (EWEs) would affect the grain quality of a temperate rice (Oryza sativa L.). In 2009 and 2010, plants were grown at two levels of [CO2] (c. 390 and 650 mu l l(-1)) and three levels of warming (ambient, +1.2 C and +2.2/2.4 degrees C) over the seasons in six independent temperature gradient field chambers (three each for ambient and elevated [CO2]). From 20 days after heading, plants were exposed to EWE with a simulated rainfall of 30 mm a day and cloud cover by shading (c. 18% of full sunlight) for 10 consecutive days. There were also control plots, which were non-treated (NT) in terms of EWE. We found that warming and EWE, both independently and in their interaction, lead to a significant reduction in the percentages of sound grains, whereas elevated [CO2] does not seem to do so. Not only warming and EWE, but also elevated [CO2] resulted in a significant increase of immature chalky grains (ICGs), which mostly consisted of milky-white chalky grains, degrading the grain quality. In addition, warming interacted positively with elevated [CO2] on ICGs, whereas the warming sensitivity of IGCs was moderated in EWEs: e.g., on average, the % of ICGs in ambient vs. elevated [CO2] were 8.5% vs. 9.4%, 10.7% vs. 18.1% and 17.8% vs. 29.8% at ambient (24.7 C), +1.2 degrees C and +2.4 degrees C, respectively, whereas they in NT vs. EWE were 1.2% vs. 16.6%, 7.7% vs. 21.1% and 19.4% vs. 28.2%. Our results tightly confirmed that elevated [CO2] leads to a significant reduction in rice grain protein content (PC). While warming had little effect on the PC, EWE had a significant positive effect, and the EWE-induced increase in PC was smaller in elevated (+3.3%) than in ambient [CO2] (+10.9%). Given the rice quality predictor of ICGs and PC, our findings imply that expected climate change and weather extremes have a great potential to degrade the quality of rice, in terms of its milling, cooking, eating, and nutritional quality, as well as market value. (C) 2013 Elsevier B.V. All rights reserved.

본 연구는 벼에 대한 물달개비, 벗풀의 경합에 따른 수량피해 예측과 경제적인 잡초관리를 위한 방제필요밀도를 구명하고자 하였다. 수원, 익산, 나주와 대전지역에서 얻어진 성적을 종합한 예측모델식에 따르면 논에서 물달개비의 경합력은 대전 0.0007445, 수원 0.0005713, 익산 0.000988, 나주에서 0.0008846으로 추정되었다. 벗풀의 경합력은 나주 0.001611에서 익산에서 0.002437의 범위를 보였다. 초종별 평방미터당 요방제 필요밀도는 물달개비는 중기제초제 처리시 22에서 39본으로, 벗풀은 8.8본에서 12.9본으로 추정되었다. Field experiments were conducted to investigate the competition relationships of main paddy weeds with transplanted rice grown in paddy conditions. Data were used to predict crop yield as a function of weed density using a rectangular hyperbola model and determine weed economic threshold (ET) levels. The rectangular hyperbola (equation 2) was fitted to rice yield to estimate weed-free rice yield ($Y_o$) and weed competitivity (${\beta}$). Its competitivity for M. vaginalis was 0.0007445, 0.0005713, 0.000988 and 0.0008846 in Daejeon, Suwon, Iksan and Naju, respectively. The competitivity at harvest represented by parameter ${\beta}$ ranged from 0.001611 in Naju to 0.002437 in Iksan for S. trifolia. The ET levels of main paddy weeds in machine transplanted rice cultivation were well estimated based on the herbicides applied and its application cost. Therefore, our results can be used to support decision-making on herbicide application for weed management in transplanted rice cultivation.

논잡초의 발생상황 및 농가수준에서 논 제초제 사용을 파악하여 농가지도의 기초자료로 활용코자 전국 농업인 1,029명을 대상으로 논에서의 우점잡초, 선호 제초제, 논제초제의 사용방법 등을 설문조사하였다. 논에 발생하는 우점잡초로는 피, 물달개비, 벗풀, 올챙이고랭이, 올방개 순이었으며, 제초제 저항성잡초로 의심되는 초종은 물달개비, 논피(강피), 올미 등으로 응답하였다. 논 제초제의 사용 선정은 자기 경험에 의한 것이 34.0%, 농약판매상 추천이 33.9%이었다. 농가에서 한번만 제초제를 처리하는 경우는 15.6%인 반면에 2회 처리하는 농가는 75.6%이었다. 농가에서 선호하는 제초제는 옥사디아존유제, 뷰타클로르입제, 뷰타클로르캡슐현탁제, 메페나셋 피라조설퓨론 에틸액상수화제, 옥사디아길유제 순이었으며, 경엽처리제 중에서는 벤타존 엠시피에이액제, 벤타존 사이할로포트 뷰틸미탁제가 각각 48.5%, 22.3%로 농가에서 많이 사용되는 제초제이었다. A fact-finding survey was conducted to obtain the basic information on nation-wide weed distribution and farmer's opinions to weed control strategy in paddy field. Most respondents considered Echinochloa spp., Monochloa vaginalis, Sagittaria trifolia, and Scirpus juncoides etc. as dominate weeds in paddy fields. And herbicide resistant weed species were M. vaginalis, S. juncoides, E. oryzicola and S. pygmaea etc. Purchase guidances for herbicide selection, experience of farmers was 34.0% and dealers recommendation was 33.9% at farmer's level. And paddy field herbicides application frequence were one time 15.6% but twice 75.6%. Preferred herbicides were ranked in the following order: oxadizone 12% EC, butachlor 5% GR, butachlor 33% CS, mefenacet pyrazodulfuron-ethyl 21.42% SC, and oxadiargyl 1.7% EC etc. in paddy fields. And in most preferred foliar herbicide were bentazone MCPA 38.6% SL and bentazone cyhalop-butyl 18.5% ME, 48.5% and 22.3%, respectively.

Myxococcus xanthus (MX, PX)와 Arabidopsis thaliana (AP37)의 protoporphyrinogen oxidase (Protox)유전자 과다발현 제초제 저항성 형질전환 벼와 비형질전환벼의 생육 및 수량에 관한 적응성 차이와 벼생육시기별 ALA 합성능력, tetrapyrrole 중간물질, 활성산소 발생, 지질과산화 작용 및 항산화효소 능력의 연관성이 조사되었다. Protox 과다발현 형질전환 벼 MX와 AP37의 초장은 이앙 후 43, 50, 65일에 비형질전환벼 비형질전환벼에 비해 유의적으로 적었고, 분얼수는 이앙 후 50일과 65일에 MX와 AP37 뿐만 아니라 PX에서도 비형질전환벼에 비해 유의적으로 적었다. 수확기의 간장과 수량은 MX, PX 및 AP37에서 그리고 고건중은 MX와 AP37에서 비형질전환벼에 비해 유의적으로 적었다. 형질전환벼 계통 MX, PX 및 AP37의 수량감소는 MX의 경우 영화수와 천립중에 의해, PX는 등숙율에 의해, AP37은 영화수, 등숙율 및 천립중에 의해서 기인되었다. 한편, 형질전환벼 계통 MX, PX 및 AP37의 수량감소는 또 다른 년차변이 연구에서도 관찰되었다. 이러한 형질전환벼계통의 생육 감소는 이앙 후 생육기간 뿐만 아니라 이앙 전 육묘기간 동안에서도 발생하여 결과적으로 수량이 감소되는 것으로 생각된다. Tetrapyrrole 중간물질 Proto IX, Mg-Proto IX 및 Mg-Proto IX monomethyl ester의 축적량, 활성산소종($H_2O_2$와 ${O_2}^-$), MDA, 및 항산화효소(superoxide dismutase, caltalase, peroxidase, ascorbate peroxidase, glutathione reductase) 및 엽록소 함량은 Protox 유전자 과다발현형질전환벼 계통과 비형질전환벼간에 유의적인 차이가 없어 이들 porphyrin 대사 경로 물질과 벼 생육 및 수량감소의 연관성은 적은 것으로 사료된다. 그러나 MX, PX, AP37의 ALA 합성능력은 광노출 후 1일과 이앙 후 52일에 비형질전환벼에 비해 유의적으로 감소하여 이 부분에 대한 상세한 연구가 추후에 수행되어야 할 것으로 보인다. The objectives of this study were to investigate fitness difference in growth and rice yield in herbicide-transgenic rice overexpressing Myxococcus xanthus and Arabidopsis thaliana protoporphyrinogen oxidase (Protox) genes and non-transgenic rice. We also aimed to determine whether these fitness differences are related to ALA synthesizing capacity, accumulation of terapyrroles, reactive oxygen species, lipid peroxidation, and antioxidative enzymes at different growth stages of rice. Plant height of the transgenic rice overexpressing M. xanthus (MX) and A. thaliana (AP37) Protox genes at 43, 50, and 65 days after transplanting (DAT) was significantly lower than that of WT. Number of tiller of PX as well as MX and AP37 at 50 and 65 DAT was significantly lower than that of WT. At harvest time, culm length and yield of MX, PX and AP37 and rice straw weight of MX and AP37 were significantly low compared with WT. The reduction of yield in MX, PX, and AP37 was caused by spikelets per panicle and 1000 grain weight, ripened grain, spikelets per panicle, 1000 grain weight, and ripened grain, respectively. On the other hand, 135 the reduction of yield in MX, PX, and AP37 was also observed in another yearly variation experiment. The reduction of rice growth in MX, PX, and AP37 was observed in seedling stage as well as growth duration in field. There were no differences in tetrapyrrole intermediate Proto IX, Mg-Proto IX and Mg-Proto IX monomethyl ester, reactive oxygen species ($H_2O_2$ and ${O_2}^-$), MDA, antioxidative enzymes (SOD, CAT, POX, APX, and GR) and chlorophyll between transgenic lines and wild type, indicating that accumulated tetrapyrrole intermediate and other parameters were not related to growth reduction in transgenic rice. However, ALA synthesizing capacity in MX, PX, and AP37 at one day after exposure to light and 52 DAT was significantly lower than that of WT. Further study is required to elucidate the mechanisms underlying the growth and yield difference between transgenic and WT lines.

This study was carried out to examine controlling effect of red rice accessions and sulfonylurea herbicide-resistant weeds by Protox inhibitors, oxyfluorfen, oxadiazon, and oxadiargyl in transgenic rice cultivation of various cropping patterns (direct seeding on dry paddy, direct seeding on flooded paddy surface, 10-day old seeding, and 30-day old seeding) under greenhouses and in fields. No phytotoxicity was observed in Protox inhibitor herbicide-resistant transgenic rice lines, MX and PX by oxyfluorfen treatment in direct seeding on dry paddy, direct seeding on flooded paddy surface, and 10-day old seeding under greenhouse conditions. However, the phytotoxicy of non-transgenic rice (WT) at 20 days after oxyfluorfen foliar application at 2,350 g ai ha under direct seeding on dry paddy and direct seeding on flooded paddy surface was 54% and 90%, respectively. On the other hand, the phytotoxicity of WT after oxyfluorfen soil application at 100 g ai ha under direct seeding on flooded paddy surface was observed by 72%. No phytotoxicity in MX and PX was observed after oxadiazon and oxadiagyl soil application under direct seeding on flooded paddy surface, but in the case of WT, the phytotoxicity occurred at 80% after oxadiazon soil application at 480 g ai ha and at 97% after oxadiargyl soil application at 68 g ai ha. The seedling stand rates of MX at oxadiargyl 68 g ai ha and PX at oxadiazon 480 g and oxadiargyl 68 g ai ha were significantly reduced compared with non-treated control in direct seeding on flooded paddy surface under field conditions. However, the seedling stand rates of red rice accessions (R2, R189, R116, and R141) as well as WT were significantly reduced by all treated rates of Protox in hibitor herbicides. Controlling effect of red rice accessions, Scirpus juncoides, Monochoria vaginalis, Echinochloa crus-galli, and Rotala indica at 43 days after soil application of Protox inhibitor herbicides in direct seeding on flooded paddy surface under field conditions was 87~96%, 78~90%, 63~100%, and 100%, respectively. Plant height and number of tiller of WT were reduced by Protox inhibitor herbicides, but the plant height and number of tiller of MX and PX were similar to those of non-treated control. Controlling effect of red rice accessions and juncoides, vaginalis, crus-galli, and indica at

본 시험은 2009년 경상북도 농업기술원 벼 재배포장에서 잡초발생 예찰 시스템 구축의 일환으로 최근 담수 직파답이 늘어나면서 벼 재배시 문제잡초인 벗풀과 미국가막사리를 대상으로 잡초 밀도별 벼와의 경합력을 구명하고 Rectangular hyperbola 모델을 기초로 잡초의 밀도에 따른 쌀 수량 감소를 예측하고 경제적인 방제 필요수준을 구명하고자 본 시험을 실시하게 되었다. 잡초 초종별 밀도 증가에 따른 벼 수량 예측식은 벗풀이 y=497.0/(1+0.003760x), $R^2$=0.869이고, 미국가막사리는 y=486.0/(1+0.007612x), $R^2$=0.887로 나타났다. 제초제 구입 비용은 $ha^{-1}$당 138,670원이었고, 제초제를 살포하는데 소요되는 인건비 등은 $ha^{-1}$당 99,360원, 쌀의 kg당 가격은 1,756원, 제초제의 방제가는 95%로 적용하였을 때 경제적 한계 허용 밀도는 잡초 완전 방제시 수량이 5톤이고 1본당 수량 감수 정도가 0.003670인 벗풀은 평방미터당 7.6본, 잡초 완전 방제시 수량이 4.9톤이고 1본당 수량 감수 정도가 0.007612인 미국가막사리는 평방미터당 3.9본이었다. 이와 같은 결과로 볼 때 잡초의 벼에 대한 경합력이 높을수록 경제적 한계 허용 밀도의 본수는 즐어 들었고, 경합력이 낮았던 잡초는 경제적 한계 허용 밀도의 본수가 증가되는 경향이었다. This study was conducted to predict the rice yield loss and to determine the economic threshold levels for direct-seeding flooded rice cultivation from competition to the most serious weeds, Sagittaria trifolia L. and Bidens frondosa L. The rice yield loss models of S. trifolia and B. frondosa were predicted as Y = 497.0/(1+0.003760x), $R^2$=0.869 and Y = 486.0/(1+0.007612x), $R^2$ = 0.887, respectively. In comparison of the competitiveness represented by parameter ${\beta}$, it was 0.003760 in S. trifolia and 0.007612 in B. frondosa, respectively. Economic thresholds calculated using Cousens' equation was negatively related with the competitiveness of weed. The economic thresholds of S. trifolia and B. frondosa were 7.6 and 3.9 plants per $m^2$, respectively.