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Toshiyuki Imaizumi 《Weed Biology and Management》2018,18(2):99-102
Weedy rice is a conspecific weed of cultivated rice (Oryza sativa L.) and is a primary weed of direct‐seeded rice production systems worldwide. The shift in the method of establishing rice, that is, from transplanting to direct seeding, is considered the main reason for the emergence of weedy rice in Asia and, more recently, Japan. Japan has increasingly adopted directly seeded rice, even though this practice remains limited. In this study, I confirmed the relationship between weedy red rice emergence and the adoption of direct‐seeded rice in Japan. Twenty‐seven areas from eight prefectures infested with weedy rice were selected to confirm the relationship between the rice planting method and the emergence of weedy rice. Fields that were severely infested with weedy rice were selected as survey fields for this study. I found no relationship between the method of planting rice and weedy rice emergence. Changes to herbicide application, duration of rice production and hand weeding also contribute to the emergence of weedy rice in transplanted rice fields in Japan. The results of this study indicate that weedy rice could become a serious problem in Japan, even in transplanted rice fields. 相似文献
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Leylani M. Juliano Dindo King M. Donayre Edwin C. Martin Jesusa C. Beltran 《Weed Biology and Management》2020,20(2):27-37
Weedy rice is morphologically similar to cultivated rice (Oryza sativa L.). It has biological characteristics that identify it as a weed. Its important weedy characteristics, that is, early and heavy seed shattering, makes it very difficult to control. Weedy rice has not been reported to be an important weed problem in transplanted, flooded rice. However, the shift to direct‐seeded rice (DSR) due to water issues and high costs of labor has increased reports of weedy rice becoming an expanding important problem in Vietnam, Malaysia, Thailand, and the Philippines. Experts believe that the growing adoption of DSR in Asian countries will result in the rise of weedy rice as one of the top troublesome weeds in rice production. Early and recent surveys in the Philippines have indicated the urgent need to increase awareness of weedy rice among farmers to allow the implementation of a number of effective location‐specific weed management strategies. These surveys and other studies conducted since weedy rice was first reported in 1991 confirmed that weedy rice and grass weed species caused major problems in DSR areas. About 35% of the 4.56 M ha harvested area in the country is planted with DSR. As cultivated and weedy rice are close relatives, it would be very difficult to implement management options very early in crop growth. However, a deeper understanding of the underlying traits of weedy rice can help develop a holistic approach toward effective and economic weed management. 相似文献
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对广东省将推广的54份杂交稻组合对稻瘟病和白叶枯病的抗病性进行了鉴定。对稻瘟病的抗病性鉴定表明:抗病组合共49个,占90.7%;其中,高抗(抗性比≥91%)组合30个,占55.6%。对稻白叶枯病的抗病性鉴定表明:没有高抗(HR)和抗(R)的组合,仅有一个杂交稻组合(西胜2175)表现为中抗(mR),仅占1.9%,其余53个组合都表现感病,占98.1%。进一步分析表明:对稻瘟病表现高抗的30个杂交稻组合都不抗白叶枯病,而中抗白叶枯病的杂交稻组合西胜2175对稻瘟病表现为中抗,抗性比为74%。 相似文献
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浙中沿海稻区稻瘟病菌生理小种的种群消长和分布研究 总被引:2,自引:0,他引:2
1996年至 1 998年 ,对分离来自浙中沿海台州各市县所获得的 1 76个单孢菌株 ,用全国统一鉴别品种共鉴定出 7群 2 2个稻瘟病生理小种。其中中 B和中 D群是台州稻区 2个主要的优势小种群 ,总的出现频率分别为 53.98%和 2 3.86% ,它们中的中 D1、中 B1 3、中 B1 5和中 B1这四个小种在我地分布范围广 ,出现频率分别高达 2 0 .4 5%、1 4 .2 0 %、1 4 .2 0 %和 1 0 .80 % ,且对多数栽种水稻致病 ,为优势小种 相似文献
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四川省水稻抗稻瘟病育种现状及发展方向 总被引:7,自引:0,他引:7
稻瘟病是四川省水稻的主要病害,实践证明,选育种植抗病品种是控制该病害的最经济有效的措施。1981年开始,植物病理工作者与遗传育种工作者经过20年的协作攻关,研究制定了一套适合四川生态特点的有关病菌生理小种、水稻品种抗瘟性鉴定的规范化技术和评价体系,探明稻瘟病菌致病性变异和水稻品种抗瘟性丧失规律,筛选出200多份稻瘟病抗源材料,育成穗颈瘟1-5级的抗病品种(组合)27个,累计推广面积达2750万hm^2,有效地控制了稻瘟病的流行。在此基础上,提出今后重点研究领域和抗病育种策略。 相似文献
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申嗪霉素1%悬浮剂在水稻及稻田环境中的残留动态研究 总被引:2,自引:0,他引:2
采用高效液相色谱法测定了申嗪霉素在水稻及稻田环境中的残留动态。结果表明中嗪霉素l%悬浮剂在水稻田土壤、田水、稻杆、糙米和稻壳中的添加回收率为77.5%~108%。申嗪霉素在3地的稻秆和田水中的消解半衰期分别为1.96~2.53d、2.06~3.61d。14d稻杆、稻壳最终残留量〈0.01mg/kg(最低检出浓度),稻米、土壤最终残留量〈0.004mg/kg(最低检出浓度)。 相似文献
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江苏省水稻区试品种(系)对白叶枯病的抗性分析 总被引:2,自引:0,他引:2
通过 1996~2000年213份江苏省水稻区试品种(系)对水稻白叶枯病抗性鉴定 ,抗性较好的品种有94-44、96218、镇稻272、汕优抗63、汕优084、金优63、109、701、7057、9510、9619、5-172、92-133、扬粳7057、泗稻98-3789、新108、镇稻 99、44/157、9522等品种 ,其中 9510、9522等在生产上推广面积较大。试验表明 ,江苏省区试品种 (系 )中常规中籼、杂交籼稻和杂交中粳稻对水稻白叶枯病抗性较差 ,全抗率分别为36.4 %、27.3%和43.3% ,而中粳稻、单季晚粳和杂交晚粳稻对水稻白叶枯病的全抗率为67.2%、71.4%和72.2% ,抗性相对较好。根据白叶枯病菌不同致病型菌株对参试品种致病率的分布情况分析 ,浙173菌株 (致病型Ⅳ)对杂交中籼、常规中粳稻和杂交中粳稻的致病率较高。这种情况和Ⅳ型菌为江苏省白叶枯病主要致病型相一致。 相似文献