10种麦田除草剂的药效试验

试验表明 :10种麦田除草剂的除草效果排列须序依次为 5 0 %麦草霸 3 0 0 0g/hm2 ,2 5 %异丙隆 3 90 0g/hm2 ,5 0 %麦草霸 22 5 0g/hm2 ,70 %麦草净 10 5 0g/hm2 ,2 5 %高渗异丙隆 1875g/hm2 ,2 0 %超级麦草灵 12 0 0g/hm2 ,70 %高渗麦草净 10 5 0g/hm2 ,5 0 %麦无草 12 0 0g/hm2 ,10 %麦草灵 15 0g/hm2 ,2 5 %敌草强 3 75g/hm2 ,5 0 %麦草霸 15 0 0g/hm2 ,10 %麦霸 15 0g/hm2 。具有推广应用前途的除草剂是不含有甲黄隆、绿黄隆成分的麦草霸、异丙隆、高渗异丙隆和敌草强     

Nitrous oxide emission from herbicide-treated soybean

 The emission of N₂O from soybean plants treated with the herbicides dichlorophenoxyacetic acid (2,4-D) and bromoxynil was studied. The N₂O flux from 2,4-D- and bromoxynil-treated soybean was 14.1 ng N₂O-N g^–1 fresh weight h^–1 and 19.7 ng N₂O-N g^–1 fresh weight h^–1, respectively, i.e. approximately twice that of the controls. The NO₂ ^–-N concentration in 2,4-D- and in bromoxynil-treated soybean was about 8 μg N g^–1 fresh weight, i.e. fivefold the concentration found in control plants. The NO₃ ^– content in herbicide-treated soybean did not differ significantly from that of the control plants. Consequently, the accumulation of NO₂ ^–-N during the assimilation of NO₃ ^–-N was thought to cause the observed N₂O release. Probably, N₂O is a by-product produced during either the reaction of NO₂ ^–-N with plant metabolites or NO₂ ^–-N decomposition. Final conclusions must await further experiments. Received: 5 November 1999     

Effects of a sulfonylurea herbicide on soil microarthropods

 The short-term effects on soil microarthropods of the herbicide triasulfuron, belonging to the chemical class of sulfonylureas, were evaluated in two fields which had never been treated with sulfonylureas, and were cultivated with winter wheat. In particular, the effects of single applications at rates corresponding to two- (rate 2) and sixfold (rate 6) the recommended agricultural rate (7.5 g active ingredient ha^–1) were analysed and compared with controls. The changes in the populations of the main groups of microarthropods were evaluated. Rate 2 had very low effects, whereas rate 6 produced a significant decrease in the number of microarthropods, Acarina and Collembola in the surface soil layer (0–7.5 cm). The Collembola were analysed at the species level. Statistical analysis revealed significant differences only for a few species, and only after treatment with the highest rate of triasulfuron. Finally, the results of the field tests were compared to those of laboratory tests carried out previously, which examined the effects of the same herbicide on a collembolan species. Received: 11 November 1998     

不同除草剂对间作玉米大豆的药害及除草效果

采用盆栽方法模拟玉米大豆间作模式栽培,选用10种土壤处理除草剂和13种茎叶处理除草剂,研究不同除草剂对玉米、大豆生长发育的影响及杂草的防效。结果表明:通过试验筛选出药害轻或药害后能恢复的5种土壤处理剂和5种茎叶处理剂,5种土壤处理剂分别为二甲戊灵、精异丙甲草胺、扑·乙·滴丁酯、乙·嗪·滴丁酯、嗪酮·乙草胺,5种茎叶处理剂分别为灭草松、噻吩磺隆、双氟·唑嘧胺、氟醚·灭草松、咪唑乙烟酸。二甲戊灵和嗪酮·乙草胺的土壤处理中玉米、大豆的株高、茎粗和干物重与清水对照差异不显著,对玉米、大豆安全,株防效分别为60.58%和60.58%,鲜重防效分别为67.12%和55.35%。精异丙甲草胺影响间作玉米的株高和茎粗,但不影响玉米干物质的积累,株防效和鲜重防效分别为71.96%和78.83%,高于其它除草剂。茎叶处理中灭草松安对玉米、大豆的株高、茎粗和干物重与清水对照差异不显著,株防效为52.7%,低于其它除草剂。噻吩磺隆处理后,玉米、大豆的株高受到抑制,茎增粗,但药害能恢复,且除草效果高于其它处理,株防效和鲜重防效分别为73.88%和96.1%。土壤处理剂二甲戊灵和茎叶处理剂灭草松对玉米、大豆更安全,土壤处理剂精异丙甲草胺和茎叶处理剂噻吩磺隆除草效果更好。     

除草剂在杨树、柳树苗圃中的应用试验

试验表明采用使它隆＋高效盖草能除草剂组合，在杨树、柳树当年扦插苗和截干苗圃中低位定向喷施，用药后30d，对双子叶阔叶杂草和单子叶禾本科杂草防除效果为92．49％以上，对苗木生长无影响。较人工除草省时、省工，成本低，见效快。     

康县牡丹园草的种类及其除草剂的选择

牡丹在我国有着很大的药用价值和观赏价值。合理地除去牡丹园的杂草让牡丹幼苗更好地生长是一项重要的工作。对康县牡丹园的杂草种类进行调研和分类,有针对性地选择相关除草剂,具有一定的除草功效。     

Effect of tillage systems and herbicide treatments on weed abundance and diversity in a glyphosate resistant crop rotation

The effect of exclusive application of glyphosate and glyphosate in combination with residual herbicides on weed species density and composition in summer crops was studied over 2 years. Field experiments consisted of three rotations including soybean and maize glyphosate-resistant cultivars in two tillage systems. Regardless of the tillage system, both glyphosate application alone and in combination with residual herbicides had a pronounced impact on the reduction in density and richness of summer herbaceous annual weeds, but the effect was greater with glyphosate in combination with residual herbicides.     

除草剂现锄对国槐生理生化影响的研究

旨在研究现锄农田常用除草剂对国槐苗生长产生抑制或促进作用的生理生化机制,并力求从中得出既能够有效杀死杂草又对国槐苗生长基本无影响的浓度。经过对现锄高、中、低三个浓度处理下国槐苗新梢生长量、叶绿素含量、丙二醛含量及膜相对透性的测定,并进行数据统计,我们总结出现锄对国槐生理生化的影响。试验结果表明:高浓度、中浓度的现锄对国槐生长发育有一定的抑制作用;并指出在国槐苗圃进行化学除草时,现锄这种除草剂使用浓度为0.25 g.kg-1,并且要加强保护措施,以免药液溅到树叶上。     

机械抛秧稻田杂草防治

在机械化抛秧稻田 ,选用稻农乐 (二氯唑啉酸 +苄嘧磺隆 ) 2 5 %悬乳剂 ,或选用丁苄 (丁草胺 +苄嘧磺隆 )现混现用 ,防除杂草效果达到优良水平 ,对水稻安全 ,可以大面积示范推广     

Effects of herbicides on three vesicular-arbuscular fungi associated with winter wheat (Riticum aestivum L.)

Summary We studied the effects of field application rates of four herbicides (Avenge, Ceridor, Dicurane, and Harrier) on spore germination and infection of wheat roots by three species of Glomus grown under conditions of low P availability. Low concentrations of Ceridor (bifenox, mecoprop) and Harrier (mecoprop, ioxynil, clopyralid) inhibited spore germination while higher concentrations were stimulatory. Avenge (difenzoquat methyl sulphate) prevented spore germination completely, while Dicurane (chlortoluron) had no effect. The herbicide applications had no significant effect on the infection rates of any of the three fungi except Harrier on G. geosporum. The herbicide treatments did, however, affect plant growth and ear yields. Ceridor and Harrier increased ear yields, while Dicurane showed marked phytotoxic effects.