二苯醚类除草剂在土壤中的降解动态及作物上的残留

于１９９２～１９９４年对乙氧氟草醚、氟磺胺草醚在土壤中的降解动态及在油料作物上的残留进行了试验研究，明确了这两种农药在土壤中的半衰期及作物上的残留特性，进而为防止除草剂对农业生态环境的污染，提出了合理使用方法     

外界环境条件对鸭跖草出苗的影响

通过提供不同外界环境条件的方法，研究了土壤含水量，播种深度及除草剂虎威对鸭跖草出苗的影响。结果表明：当土壤含水量为40％时，鸭跖草的出苗率最高。随着土壤含水量的增高，鸭跖草的出苗率呈下降趋势。适于鸭跖草种子出苗的土壤含水量小于大田作物生长发育所需的土壤含水量；播种越深，鸭跖草出苗率越低，播种深度与鸭跖草的出苗率（P＜0．05）表现出显著的负相关；除草剂虎威对鸭跖草种子萌发与出苗有一定的负效应，经播后苗前也表处理后，剂量为25.0mg/m^2的处理，萌发抑制率约为对照的50％。当虎威使用量达到200.0mg/m^2时，鸭跖草种子萌发抑制率可达到90％，但此剂量将对作物造成危害。     

菌株Shigella flexneri FB5响应氟磺胺草醚蛋白质组学分析

为明确氟磺胺草醚降解菌的蛋白质组学相关机理,针对实验室前期筛选得到的高效降解菌Shigella flexneri FB5,在明确菌株对氟磺胺草醚高效降解的基础上,研究进行了蛋白提取和双向电泳试验。结果发现氟磺胺草醚诱导下菌株差异蛋白点13个,使用质谱技术对它们进行鉴定。通过生物信息学比对得到其功能,并对目标蛋白的基因进行PCR扩增与测序。结果表明:研究得到氟磺胺草醚诱导下菌株两个相关基因,测序后发现基因F3序列与E.coli结合蛋白dps基因同源性是100%,基因F6序列与沙门氏菌肠溶亚种血清变型索菲亚菌S1635外膜蛋白基因和E.coli SYW004外膜蛋白基因A相似度是87%,同时对这两个基因所在家族功能进行分析,并且推测出基因的理化性质。     

六种有机硅助剂对氟磺胺草醚的增效作用及其增效机理初探

采用温室盆栽法研究了6种不同结构的有机硅助剂对氟磺胺草醚防除阔叶杂草苘麻的增效作用及其增效机制。于苘麻4~5叶期,分别喷施添加有机硅助剂Agrowet 818、Agrowet 820、GY-S903、Sio-683、TD-600和TD-6408的氟磺胺草醚药液,测定药液对苘麻的抑制率及增效比;取苘麻6龄叶片,分别测定添加不同有机硅助剂后氟磺胺草醚药液的表面张力、在叶片上的扩展直径及最大持留量。结果表明:6种有机硅助剂对氟磺胺草醚的增效作用可达15.88%~23.04%;可以显著降低氟磺胺草醚药液的表面张力(由60.7 m N/m降至20~25 m N/m),使药剂在叶片表面的最大持留量增加30%~70%,扩展直径由4.7 mm增至6.5~8.2 mm;其中,Agrowet 820增效作用最明显,可使表面张力降低65%,最大持留量增加69%,扩展直径增加74%,防效提高23.04%。     

Effects of Methylated Soybean Oil Adjuvant on Fomesafen Efficacy to Weeds

Tank-mix adjuvant has the potential to improve the weed control efficacy of post-emergence herbicides. In order to study the synergistic effect of adjuvant, the effects of different rates of fomesafen alone or applied methylated soybean oil adjuvant（MSO） were sprayed on redroot pigweed, abutilon and black nightshade under greenhouse condition. The results showed that fomesafen had different performance on the three weeds, and MSO adjuvant could effectively increase the control. The nightshade control was lower than other two weeds with all the fomesafen doses from 131.25 to 506.25 ga.i. · hm-2 with or without adjuvant. The control of abutilon was between the black nightshade and the redroot pigweed, and had better control at 375 ga.i. · hm-2 with adjuvant or 506.25 ga.i. · hm-2 alone or with adjuvant respectively. The results indicated that mixing adjuvant with fomesafen improved the control on weeds, especially at the low rate. Black nightshade was more difficult to control. The redroot pigweed had the most susceptibility to fomesafen alone or with adjuvant.     

pH对氟磺胺草醚水解的影响

采用试验分析方法研究了氟磺胺草醚在不同pH缓冲溶液中的水解作用.结果表明,随着溶液pH值的增大,氟磺胺草醚的水解反应逐渐减慢,速率常数K减小,半衰期相应地增大.氟磺胺草醚在pH为5.0、6.0、7.0、8.0、9.0的缓冲液中的水解半衰期分别为105.74、157.41、183.26、215.16、247.40 d.     

假苍耳的化学防除

采用混配方法系统研究了假苍耳的化学防除。结果表明,草甘膦对假苍耳有较好的防除作用,加入助剂能够提高草甘膦对假苍耳的防效,生助黑助(NH4)2SO45g(NH4)2SO41g对照,生助增效最大,最大株防效为98.03%～99.28%,最佳防除时期为4～6叶期;氟磺胺草醚对假苍耳有较好的防除作用,加入助剂能够提高氟磺胺草醚对假苍耳的防效,(NH4)2SO45g(NH4)2SO41g生助黑助对照,其中(NH4)2SO45g增效最大,最大株防效为95.15%～97.19%,最佳防除时期为4～6叶期。     

The use of fomesafen for pre-emergence weed control in cotton

The herbicide fomesafen was found to be selective in preplanting and pre-emergence treatments in cotton (Gossypium hirsutum L.). It was effective due to residual soil activity in controlling some of the most troublesome weeds in cotton fields,i.e., pigweed (Amaranthus spp.), black nightshade (Solarium nigrum L.), velvetleaf (Abutilon theophrasti Medik.) and cocklebur (Xanthium spp.). The best soil activity of fomesafen was achieved from pre-emergence or preplanting applications which were activated when the soil was wetted by rain or sprinkler irrigation, but the herbicide caused damage to the crop’s foliage if rain fell just after the cotton emergence. The most effective and safest method for applying fomesafen in cotton fields was preplanting followed by mechanical incorporation to a depth of 10 cm. Combinations of fomesafen with trifluralin were effective and completed the spectrum of controlled weeds in cotton, including annual grasses, common purslane (Portulaca oleracea L.) and field bindweed (Convolvulus arvensis L.).     

Responses of otebo bean (Phaseolus vulgaris L.) to postemergence herbicides

Ontario otebo bean growers have few herbicide options available for weed management. Six field trials were conducted in Ontario, Canada, over a 2 year period (2003 and 2004) to evaluate the tolerance of otebo bean to the postemergence (POST) application of bentazon at 1080 and 2160 g ai ha⁻¹, fomesafen at 240 and 480 g ai ha⁻¹, sethoxydim at 500 and 1000 g ai ha⁻¹, quizalofop-p-ethyl at 72 and 144 g ai ha⁻¹, imazamox plus fomesafen at 25 + 200 and 50 + 400 g ai ha⁻¹, and imazamox plus bentazon at 25 + 600 and 50 + 1200 g ai ha⁻¹. All treatments, including the untreated control, were maintained weed-free during the growing season. The POST application of bentazon, imazamox plus fomesafen, and imazamox plus bentazon caused as much as 9% visual injury and reduced the plant height ≤ 12%, reduced the shoot dry weight ≤ 32%, and delayed maturity but had no adverse effect on the yield of otebo bean. Fomesafen, sethoxydim, and quizalofop-p-ethyl applied POST caused as much as 8% visual injury but this was transient and had no adverse effect on the plant height, shoot dry weight, seed moisture content, and yield of otebo bean, except for quizalofop-p-ethyl, which reduced the shoot dry weight as much as 18%. Based on these results, bentazon, fomesafen, sethoxydim, quizalofop-p-ethyl, imazamox plus fomesafen, and imazamox plus bentazon applied POST have an adequate margin of crop safety for weed management in otebo bean production in Ontario. However, care must be taken to avoid spray overlaps to prevent injury from bentazon, imazamox plus fomesafen, and imazamox plus bentazon.     

除草剂虎威的标记合成

5-( 2-氯-4-三氧甲基 )苯氧基 )- N-(甲基磺酰基 ) - 2-硝基苯甲酰胺 (虎威 )的14 C标记合成经 6步完成。其放化收率为 1 8 1 5 % (以14 C 以苯甲酸计 ) ,放化纯度经薄板检测大于 99%。