乙氧氟草醚在花生上的残留动态研究

乙氧氟草醚在花生上的残留动态研究／陆贻通（浙江省农业厅环保站），徐进…环境污染与防治．－１９９４，１６（１）．－７～８为防止新除草剂乙氧氟草醚对农业生态环境污染，作者进行了该农药在花生上残留动态试验研究。残留动态试验：设２个用药剂量，每亩分别用２３．...     

草甘膦等不同茎叶处理除草剂对棉田杂草的防除效果

研究了草甘膦异丙胺盐、乙氧氟草醚、草铵膦3种茎叶处理除草剂单用及与二甲戊灵、精异丙甲草胺2种土壤处理除草剂混用后,对棉田苗期杂草的防效。试验结果表明,23.5%乙氧氟草醚EC按照105.8、176.3、246.8g·hm~(-2)和41%草甘膦AS按照615g·hm~(-2)使用对棉田杂草的防效较差;20%草铵膦AS按照900、1350g·hm~(-2)处理表现优良;同时将草甘膦分别与乙氧氟草醚、草铵膦、二甲戊灵和精异丙甲草胺混合使用后,均有明显增效作用,与单剂相比,既提高了速效性,又延长了持久性,混合使用后尤其以草甘膦+乙氧氟草醚的增效作用最为明显。     

几种棉田苗期茎叶除草剂的应用效果比较

以非抗除草剂棉花品种豫068为材料,选用4种市场常见茎叶除草剂,设6个药剂处理（乙草胺90%乳油、异丙草莠40%悬乳剂、草甘膦异丙胺盐41%水剂、乙氧氟草醚20%乳油、乙氧氟草醚+乙草胺、乙氧氟草醚+草甘膦）和1个清水对照,在棉花苗期四叶一心期定向喷施,研究其对棉苗安全性及对杂草防效。结果表明：6个药剂处理对禾本科杂草都有较好的防效,持效期较长,而且对棉花安全。草甘膦异丙胺盐41%（质量分数,下同）水剂1 350 g·hm^－2（有效成分用量,下同）的杂草防效最好,可作为棉花茎叶期的理想除草剂。乙氧氟草醚36 g·hm^－2 +乙草胺380 g·hm^－2和乙氧氟草醚20%乳油36 g·hm^－2 +草甘膦异丙胺盐41%水剂680 g·hm^－2处理对棉田杂草的总防效也较好,可作为辅助除草剂。     

八种除草剂对亚麻幼根和幼芽生长的影响初探

本文主要概述甲咪唑烟酸、苯达松等8种除草剂对亚麻幼根和幼芽生长的影响,室内生测结果表明:亚麻幼根对三氟啶磺隆比较敏感,EC50为8.10mg/L;亚麻幼芽对甲咪唑烟酸、氯氟吡氧乙酸、三氟啶磺隆和乙氧氟草醚敏感,EC50分别为2.14mg/L、0.35mg/L、0.62mg/L、2.34mg/L;在生测剂量下,乙氧氟草醚和草酮两药剂对亚麻幼根的生长有促进作用,对幼芽的抑制率相对较低.     

黄河流域棉区北部机采棉田恶性杂草的化学防除研究

影响黄河流域棉区北部棉花机械采收的恶性杂草主要有藜、反枝苋、铁苋菜、龙葵、苘麻、田旋花、打碗花和裂叶牵牛等。于2013、2014、2016年研究了这些杂草的化学防除方法。苗蕾期用嘧硫草醚和三氟啶磺隆对藜、反枝苋、龙葵、苘麻、田旋花、打碗花的防效较好，药后30～40 d的株防效超过95%；对铁苋菜和鹅绒藤的防效较差，同期株防效不足85%；对裂叶牵牛的防效居中，同期株防效为84%～94%。花铃期用嘧硫草醚和三氟啶磺隆对上述恶性杂草的防效下降；而乙氧氟草醚的杀草活性较强，药后25～40 d株防效可达100%（裂叶牵牛除外）。草甘膦在苗蕾期、花铃期和吐絮期对各种恶性杂草的株防效均在95%～100%（花铃期的裂叶牵牛除外）。上述处理对棉花均未产生明显药害，对产量也无显著影响。针对黄河流域棉区机采棉田，苗蕾期应用嘧硫草醚或/和三氟啶磺隆，花铃期应用乙氧氟草醚或草甘膦，吐絮期应用草甘膦，可较好地防除恶性杂草。     

田旋花对7种土壤处理除草剂的敏感性测定及其防除药剂筛选

为明确新疆棉田田旋花对7种土壤处理剂的敏感性,采用种子生物测定法检测了田旋花对7种土壤处理剂的敏感性,通过室内盆栽试验研究供试药剂对田旋花的防治效果。结果表明,新疆棉田田旋花对不同土壤处理剂的敏感性存在显著差异,对24%乙氧氟草醚EC的敏感性最高,对96%异丙甲草胺EC和50%扑草净WP的敏感性次之,对12.5%恶草酮EC敏感性最低。供试土壤处理剂的各处理对棉田田旋花均具有一定的抑制作用,对棉花安全。50%扑草净WP对田旋花防效显著高于其他药剂,其次为24%乙氧氟草醚EC。     

除草剂不同时期应用对机直播稻田杂草的防除作用

为开发机直播水稻田高效安全的封闭除草剂,采用大田试验,比较了不同时期应用含有乙氧磺隆成分的除草剂对阔叶草和莎草科杂草的防除效果。结果发现,播种时同步喷施五氟·乙氧或混配乙氧磺隆与其他除草剂能够有效抑制机直播稻田阔叶草和莎草科杂草的萌发和生长,且对水稻出苗安全。机直播后10 d或15 d施用对阔叶草防效下降,但播种15 d后撒施0.65%五氟·乙氧控释颗粒剂97.5 g/hm²对杂草防效较好,密度防效达到90%以上。表明采用五氟·乙氧或混配乙氧磺隆与其他除草剂防除机直播稻田阔叶草,越早施药效果越好。但如果因气候条件或其他因素影响错过施药窗口期时,撒施0.65%五氟·乙氧控释颗粒剂97.5 g/hm²或喷施30%氰氟草酯112.5 g/hm²+30%五氟·乙氧90 g/hm²也可以防控绝大部分直播田杂草。     

240克/升乙氧氟草醚乳油防除水稻田杂草药效试验

对山东产240克/升乙氧氟草醚乳油防除水稻移栽田杂草效果进行试验研究,结果表明:该药剂为水稻田广谱高效除草剂,能有效防莎草科杂草及阔叶杂草,且对水稻安全,推荐量15 ml/667 m~2。     

三种花生田土壤处理除草剂优化配施技术研究

采用二次饱和D-最优设计,研究三种土壤处理除草剂配施剂量对花生田杂草干重和荚果产量的影响。结果表明:三种除草剂单施时显著影响杂草干重和荚果产量,影响作用大小依次为235g·L~(-1)乙氧氟草醚EC330g·L~(-1)二甲戊灵EC960g·L~(-1)精异丙甲草胺EC;在低浓度水平时,随除草剂施用剂量增加,杂草干重逐渐降低,而荚果产量逐渐提高。三种除草剂配施时,杂草干重最低值319.00kg·hm~(-2),最优配施组合为960g·L~(-1)精异丙甲草胺EC 865.92g·hm~(-2)+330g·L~(-1)二甲戊灵EC 693.31g·hm~(-2)+235g·L~(-1)乙氧氟草醚EC 120.35g·hm~(-2);花生荚果产量最高为4338.88kg·hm~(-2),最优配施组合为960g·L~(-1)精异丙甲草胺EC 852.44g·hm~(-2)+330g·L~(-1)二甲戊灵EC 725.66g·hm~(-2)+235g·L~(-1)乙氧氟草醚EC 137.98g·hm~(-2)。本试验条件下,三种除草剂配施杂草干重≤600kg·hm~(-2)、荚果产量≥4000kg·hm~(-2)的最优配施剂量组合为:960g·L~(-1)精异丙甲草胺EC 644.06~808.74g·hm~(-2)、330g·L~(-1)二甲戊灵EC 701.66~866.41g·hm~(-2)、235g·L~(-1)乙氧氟草醚EC 111.04~137.11g·hm~(-2)。     

氯氟草醚乙酯防除大豆杂草

为了探讨氯氟草醚乙酯在大豆田的应用技术,在温室盆栽条件下研究了氯氟草醚乙酯的除草效果、对大豆的安全性、对后茬作物的影响及甲酯化植物油对其活性的影响.结果表明30%氯氟草醚乙酯水剂茎叶处理对阔叶杂草有较高的活性,药效反应迅速,20 mL a.i.·hm-2的防效高于25%氟磺胺草醚水剂300 mL a.i.·hm-2,20～30mL a.i.·hm-2处理4 d对阔叶杂草的目测防效达到78%～82.5%.处理7 d对阔叶杂草的目测防效达到88%～91%,其对禾本科杂草也有一定的防效.氯氟草醚乙酯茎叶处理对大豆有一定程度的药害,随着用量的加大药害增大,但随着大豆生长,逐渐恢复正常,高浓度(100、120 mL a.i.·hm-2)有死苗现象,其药害与三氟羧草醚近似.氯氟草醚乙酯无土壤残留,喷药一个月后种植玉米、小麦均正常出苗、生长发育正常.甲酯化植物油能明显提高氯氟草醚乙酯的活性.综合药效与药害考虑,30%氯氟草醚乙酯水剂在大豆田茎叶处理用量以20～30 mL a.i.·hm-2为宜,在使用中应加入喷液量0.5%的甲酯化植物油.     

呋虫胺在水稻生态系统中的残留消解及膳食风险评估

为评价呋虫胺在水稻生态系统中的残留消解行为和产生的膳食摄入风险,于2014年在海南、湖南和黑龙江进行了规范残留试验,建立了高效液相色谱法（HPLC）的分析方法检测呋虫胺在水稻糙米、稻壳、稻株、土壤、田水中的残留,并对我国不同人群的膳食暴露风险进行了评估。样品经乙腈提取,NH₂柱层析净化,高效液相色谱-紫外检测器（HPLC-UV）检测,外标法定量。结果表明,在0.02~0.5 mg/kg添加水平下,呋虫胺的平均回收率在75%~114%之间,相对标准偏差（RSD）在0.5%~19.0%之间;呋虫胺的最低检测浓度（LOQ）,稻株与稻壳中为0.1 mg/kg,糙米中为0.05 mg/kg,土壤与田水中为0.02 mg/kg;呋虫胺最小检出量（LOD）为0.08 ng。呋虫胺的消解基本符合一级动力学方程,半衰期在稻株中约0.5 d,田水中约1 d,土壤中约5 d。距末次施药后14 d糙米中呋虫胺的残留中值为0.058 mg/kg,最大残留值为0.13 mg/kg,低于我国规定的最大残留限量1 mg/kg。风险评估表明中国人群对稻米中呋虫胺长期膳食摄入的慢性风险较低。     

转Bt基因水稻Cry1Ab杀虫蛋白在水稻土中的降解

室内研究了转 Bt基因水稻克螟稻 2号和华池B6 叶片中的Cry1Ab杀虫蛋白在稻田水稻土中的降解动态。分别将克螟稻 2号的粉碎叶片和华池B6 的整张叶片埋入 3种土壤 (即老黄筋泥田、青紫泥田和黄松田 )中 ,此后每隔 6～ 10d测定土壤或叶片中的Cry1Ab含量。克螟稻 2号粉碎叶片中的Cry1Ab均以处理后的前 36d,尤其是前 6d的降解较快 ,其中在青紫泥田中最快 ,黄松田中最慢。在处理后 6～ 36d内 ,不同土壤中的Cry1Ab残留量有显著差异 ,黄松田中的明显最高 ,老黄筋泥田中的次之 ,青紫泥田中的为最低 ;此后土壤间的残留量差异逐渐缩小 ,至处理后 78d差异已不明显。土壤淹水可显著加快华池B6 叶片中Cry1Ab的降解 ,且淹水后其降解动态在不同土壤之间十分相似 ;淹水对Cry1Ab降解的促进作用仅发生在前 12d之内 ,此后多数时间内残留量在淹水与非淹水处理间无显著差异。建立了各处理中Cry1Ab降解的动力学指数方程 ,相应地得出了其降解的半衰期。还讨论了土壤有机质和微生物等因子对土壤中Cry1Ab降解的影响。     

排草丹除草剂在水稻上残留动态研究

 报道了48％排草丹水剂在水稻上的残留分析方法及稻田生态环境中残留消解动态试验研究，计算出排草丹在稻株、土壤和水中降解半衰期。每亩施用3.0 m1，兑水50 kg,在杂草2～3叶期喷施一次，距收期60天,稻谷中排草丹及其代谢产物的最终残留量低于最低检出浓度0．02 mg／kg。     

苯醚甲环唑在水稻和稻田中的残留

  为明确苯醚甲环唑在稻田系统的使用安全性,调查了我国3个不同水稻种植区域(湖南长沙、吉林长春和浙江杭州)苯醚甲环唑在稻田系统中的残留消解动态以及在糙米、稻壳、水稻茎秆和土壤中的最终残留量。按高剂量(112.5 g/hm2)施药1次后,苯醚甲环唑在不同种植区域水稻植株、稻田水和土壤中的半衰期分别为6.1~8.9 d,5.3~6.2 d和3.8~4.1 d。各试验点最终残留结果表明,施药后28 d采样时糙米中苯醚甲环唑的最终残留量均<0.01 mg/kg,水稻茎秆中含量最高,土壤中均未检出苯醚甲环唑(<0.01 mg/kg)。结合生产实际,按该试验设计的施药剂量、施药次数和采收间隔期,糙米、水稻茎秆和稻壳中苯醚甲环唑的残留量是安全的,但若是稻渔共作种植方式,则应尽量避免该农药的使用,以免对鱼类造成不利影响。     

Rice husk biochar application to paddy soil and its effects on soil physical properties,plant growth,and methane emission

The objective of this study was to investigate the effects of the application of rice husk biochar on selected soil physical properties, rice growth, including root extension, and methane (CH₄) emissions from paddy field soil. Three replication experiments were conducted using outdoor pot experiments utilizing commercial rice husk biochar mixed with paddy soil at a rate of 0 (control), 2, and 4 % (weight biochar/weight soil) in which the rice was cultivated for 100 days under a continuously flooded condition. The physical properties of soils were analyzed before and after the growing periods. Some parameters of rice growth and CH₄ emissions of paddy soils were monitored weekly during the experiment. Root extension was also analyzed after harvesting. The experiments showed that the application of rice husk biochar improved the physical properties of paddy soils. It led to a decrease in bulk density and an increase in saturated hydraulic conductivity, including the total pore volume as well as the available soil water content. The shoot height of rice plants was significantly higher in soil amended with 4 % biochar than that in the control soil. However, other plant growth parameters and root extension were only slightly affected by the application. It was also found that amending soil with biochar led to a reduction of the total CH₄ emissions by 45.2 and 54.9 % for an application rate of 2 and 4 %, respectively, compared with the control. Our results showed that the higher the application rate, the stronger the effect of biochar was observed. More research is still necessary for a better understanding of the underlying mechanisms.     

苯醚甲环唑和嘧菌酯在水稻中的残留消解动态及残留分析

本文建立了气质联用仪测定稻田环境中苯醚甲环唑和嘧菌酯的残留分析方法,对苯醚甲环唑和嘧菌酯在水稻、土壤和田水中的消解动态和残留规律进行了研究。苯醚甲环唑和嘧菌酯在糙米、稻壳、植株、土壤和田水中的最低检测浓度均为0.20 mg/kg,最小检出量为0.2 ng,在不同样品中的平均加标回收率为80.8%~109.5%,相对标准偏差在1.7%~19.7%之间。田间试验结果表明,苯醚甲环唑和嘧菌酯在水稻植株和田水中的残留消解动态规律均符合一级动力学反应模型,苯醚甲环唑在水稻植株和田水中的残留消解半衰期分别为6.3~11.6 d和1.4~11.6 d;嘧菌酯在水稻植株和田水中的残留消解半衰期分别为3.6~8.7 d和2.9~23.1 d。以推荐剂量600 g/hm2和1.5倍推荐剂量900 g/hm2,最多施药3次,距最后一次施药15 d时,苯醚甲环唑和嘧菌酯在糙米中的最高残留量分别为0.461 mg/kg和0.634 mg/kg,低于我国国家标准《食品中农药最大残留限量》(GB2763-2014)中规定的糙米中苯醚甲环唑最大残留限量0.5 mg/kg和欧盟、美国规定的糙米中嘧菌酯最大残留限量5.0 mg/kg。     

Effect of water management on greenhouse gas emissions and microbial properties of paddy soils in Japan and Indonesia

This research aims at elucidating the greenhouse gas emissions and its related soil microbial properties in continuously flooded or intermittently drained paddy soils in Japan and Indonesia. The study in Japan comprises alluvial soil and peat, cultivated to rice variety Nipponbare, while in Indonesia comprised alluvial soil cultivated to rice variety Siam Pandak. Intermittent drainage was performed to half number of the plot in 6 days interval, starting at tillering or heading stage of rice, while the other half number of plot was kept flooded as control. The experiments were carried out to follow the randomized block design with three replications. Gas samples were taken in weekly basis, except during the treatments (i.e., every 2 days interval) and analyzed for methane (CH₄) and nitrous oxide (N₂O) concentrations. Soil samples were and analyzed for the population of methanogenic bacteria, denitrifiers, methane production and consumption potentials, and methanogenic substrate. Plant growth parameters were also observed. The results showed that intermittent drainage significantly reduced greenhouse gas emission from paddy soil of Indonesia and Japan without significant changes in soil microbial population. The reductions of greenhouse emission from Japanese peaty and alluvial paddy soil due to intermittent drained were about 32 and 37%, respectively. Meanwhile, the reductions in greenhouse gas emission from alluvial soil of Indonesia due to intermittent drainage were very similar to that of in Japan, i.e., average about 37%. This suggests that intermittent drainage can be an appropriate technology option to reduce the greenhouse gas emission from paddy soil in Japan and Indonesia.     

花后水分亏缺对水稻产量和品质的影响

2000~2001年设置盆栽试验,在人为控制水分的条件下,造成水稻齐穗后遭受干旱的条件,研究了花后水分亏缺对稻谷产量和稻米品质的影响。结果表明,水稻齐穗后25 d内,是水稻产量形成的关键时期,这一阶段干旱缺水,将对稻谷产量产生重大影响;齐穗25 d以后断水,由于土壤田间持水量尚能供应10 d左右的生理需水,影响大幅减弱。稻米品质与谷粒的充实程度显著相关,在进行优质稻的栽培中应尽量保持后期的田间水分,排水时间不能早于齐穗后25 d。     

运用气相色谱同时测定稻田稻瘟酰胺和醚菌酯残留量

为了全面准确地了解稻瘟酰胺和醚菌酯在稻田中使用后的生态环境安全性,借助气相色谱分析技术,通过添加回收试验研究并建立了同时测定稻田样品稻瘟酰胺和醚菌酯残留量的方法。结果表明：稻田水样品用二氯甲烷直接萃取;稻田土壤和水稻植株样品用丙酮-水（体积比9∶1）混合液提取,经二氯甲烷萃取后,过弗罗里硅土层析柱净化,再用GC-ECD检测。当稻瘟酰胺和醚菌酯在稻田水、土壤和水稻植株中的添加质量浓度分别为0.05、0.50和1.00 mg/L时,平均回收率为91.0%～106.7%,相对标准偏差为2.3%～12.3%。     

Resistance levels and fitness of protoporphyrinogen oxidase (PROTOX) inhibitor-resistant transgenic rice in paddy fields

We previously confirmed that the transgenic rice line, M4, was about 200-fold more resistant to oxyfluorfen than the wild-type (WT) rice in whole-plant bioassays in pots. The transgenic rice line was also cross-resistant to other protoporphyrinogen oxidase (PROTOX)-inhibiting herbicides, acifluorfen, carfentrazone, and oxadiazon. The objectives of this research were to (a) verify the resistance of transgenic rice plants to commercial doses of PROTOX-inhibiting herbicides under paddy field conditions, (b) compare the growth, yield, and grain quality of transgenic and WT rice under weed-free conditions in a paddy field, and (c) determine the responses of transgenic and WT rice plants to chilling and drought stress. In the field, M4 was resistant to PROTOX inhibitors oxyfluorfen, acifluorfen, carfentrazone, pyraflufen, and oxadiazon in transplanted and direct-seeded rice culture. The transgenic and WT plants had similar plant heights and number of tillers. However, the yield of M4 at T₄ and T₅ generations was 7–8% less than that of WT plants. This was due to reduced number of spikelets per panicle and reduced grain weight. Head rice yield, immature kernels, damaged kernels, palatability, and protein and amylose contents were similar between M4 and WT rice. There was no difference in chilling injury between WT and M4, but M4 was more tolerant to drought stress than WT plants. PROTOX inhibitor-resistant rice is agronomically viable. It will expand the herbicide options in rice production. Follow-up research is required to elucidate the mechanisms underlying the slight yield difference and differential drought response between WT and transgenic rice.