Effects of salinity and desalination on seed germination of six annual weed species

The effects of various salinities and desalination on seed germination of six annual glycophytes （Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum） were studied in Horqin Sandy Land, Inner Mongolia, China. NaCl solutions of five concentrations （0 mM, as the control, and 50, 100, 200 and 300 mM） were used for saline stress and desalination treatments. Increasing salinity significantly reduced germination percentages of A. sieversiana, A. scoparia, Ch.virgata and Ch. acuminatum, but had no effect on the germination percentages of E. pilosa. Lower salinity levels （50 mM） significantly increased germination percentage of Ch. glaucum. High salinity might be a precondition for germi- nation after desalination for five of the six species, excepting E. pilosa at NaCl concentration of 300 mM in comparison with non-primed seeds. Higher salinity （200 mM） led to some specific ion toxicity and reduced seed viability of A. sieversiana. No specific ion toxicity but an osmotic effect limited the germination of other five species was observed The final germination percentages （salinity stress and desalination） of the six species showed three variations in comparison with the controls, namely, indiscrimination, stimulation, and reduction. Germination responses to salinity and desalination suggested that the six species were separated into three categories. Three species （A. sieversiana, Ch. virgata and Ch. acuminatum） showed similar germination responses to salinity with those of halophyte, but also showed a lower tolerance limit than most halophytes, although this was not always the case. A. scoparia and Ch. glaucum exhibited some ‘salt stimulation’ in seed germination percentages after desalination, whereas E. pilosa did not show any obvious responseto salinity. Therefore, salinity usually induces dormancy of seeds with strong germination capacity in fresh water, but has few, or even positive, effects on seeds with strong innate dormancy.

黄芩田茎叶处理除草剂筛选试验

为了筛选出适用于黄芩田防除一年生杂草的除草剂种类或组合,通过调查黄芩田杂草种类、数量,并针对主要杂草,从13种有代表性的茎叶处理除草剂中筛选出对黄芩安全性好的种类进行防效试验,确定除草效果及用量。结果表明,60 g/L烟嘧磺隆可分散油悬浮剂750.0 mL/hm^(2),12%砜嘧磺隆可分散油悬浮剂120.0、187.5 mL/hm^(2)以及10.8%精喹禾灵水乳剂450.0、675.0、1350.0 mL/hm^(2),108 g/L高效氟吡甲禾灵乳油375.00、450.0、900.0 mL/hm^(2)等处理对黄芩安全,鲜重减退率为-17.96%~-1.35%;480 g/L灭草松水剂等其他药剂处理黄芩植株全部或多数枯死、植株弱小发黄,对黄芩不安全。药后30 d,12%砜嘧磺隆可分散油悬浮剂120.00、187.50、240.00、375.00 mL/hm^(2)处理对黄芩田一年生阔叶杂草的总体株防效为84.08%~90.55%,鲜重防效为89.30%~95.38%;对一年生禾本科杂草的总体株防效为54.90%~73.20%,鲜重防效为60.16%~78.52%。10.8%精喹禾灵水乳剂450.00、675.00 mL/hm^(2)处理对黄芩田一年生禾本科杂草的株防效为90.20%~95.42%,鲜重防效为93.19%~97.00%。108g/L高效氟吡甲禾灵乳油375.00、450.00 mL/hm^(2)处理对黄芩田一年生禾本科杂草的株防效为95.42%~99.35%,鲜重防效为97.23%~99.54%。可以使用12%砜嘧磺隆可分散油悬浮剂120.0~187.5 mL/hm^(2)防除黄芩田以反枝苋、马齿苋、牛筋草等为主的一年生杂草,且对黄芩安全。当禾本科杂草群体较大时,可加入10.8%精喹禾灵水乳剂450.00~675.00 mL/hm^(2)或108 g/L高效氟吡甲禾灵乳油375.00~450.00 mL/hm^(2),以提高对禾本科杂草的防效。

Weed Management in Azuki Bean with Postemergence Herbicides

A limited number of postemergence (POST) herbicides are available for weed management in azuki bean production in Ontario. A total of three field trials were conducted during 2017 to 2019 at the Huron Research Station, University of Guelph, Exeter, Ontario, Canada to evaluate the efficacy of various postemergence (POST) herbicides for weed control in azuki bean. Fomesafen, acifluorfen and acifluorfen + Assist® caused up to 6% crop injury and weed interference reduced azuki bean yield up to 42%. Bentazon, bentazon Forte, bentazon/acifluorfen, bentazon + fomesafen + Assist®, bentazon + fomesafen + Turbocharge® and bentazon Forte + fomesafen caused up to 16% injury and weed interference reduced azuki bean yield up to 53%. Fomesafen, acifluorfen, acifluorfen + Assist®, bentazon, bentazon Forte, bentazon/acifluorfen, bentazon + fomesafen + Assist®, bentazon + fomesafen + Turbocharge® and bentazon Forte + fomesafen provided 36% to 88% control of redroot pigweed (Amaranthus retroflexus L.), common ragweed (Ambrosia artemesiifolia L.), and common lambsquarters (Chenopodium album L.). Fomesafen, acifluorfen + Assist® and acifluorfen provided 59% to 83% control of flower-of-an-hour (Hibiscus trionum L.), but bentazon, bentazon Forte, bentazon/acifluorfen, bentazon + fomesafen + Assist®, bentazon + fomesafen + Turbocharge® and bentazon Forte + fomesafen provided 78% to 99% control of H. trionum. All POST herbicides evaluated provide 99% to 100% control of wild mustard (Sinapis arvensis L.) in azuki bean. Based on these results, none of the POST herbicide evaluated that included bentazon can be used safely for the control of annual broadleaved weeds in azuki bean under Ontario environmental conditions.

Comparative Efficacy of Common Broad Leaf Herbicides against an Invasive Weed: <i>Parthenium</i><i>hysterophorus</i>L.

Parthenium hysterophorus L. (parthenium weed) is an annual weed that grows rapidly in disturbed land. It is considered as one of the most hazardous weeds in Pakistan as it poses serious health problems to livestock as well as severe allergenic reactions in humans. It has invaded the Punjab and Khyber Pakhtunkhwa provinces and also been spreading in other parts of the country where it poses a risk for the grazing lands, roadsides, forests, wet lands, waste lands and of all types of cropped and non-cropped areas in Pakistan. The present studies were carried out to determine the impact of four locally available broad leaf herbicides viz;Stomp 455 CS (pendimethalin), Buctril Super 60 EC (bromoxynil + MCPA), Vantage 48 SL (glyphosate) and Logran Extra 750 WG (triasulfuron + terbutryn) (@ recommended and ½ of recommended dose) against P. hysterophorus grown in pots at research field of CABI CWA, Rawalpindi. All herbicides were applied at three growth stages (rosette, bolted and flowering). The observations for the mortality of P. hysterophorus were made 2 and 4 weeks after spray. The glyphosate was the most effective and reported 100% mortality of P. hysterophorus plants at flowering stage followed by bromoxynil + MCPA (89%), pendimethalin (80%) and triasulfuron + terbutryn (61%) at recommended dose after 4 weeks of spray. All tested herbicides achieved a mortality between 38% - 86% at rosette while 54% - 96% mortality at bolted stage after 4 weeks. Initially, 2 weeks after spray at flowering stage glyphosate caused 53% wilting followed by 49% (bromoxynil + MCPA), 33% (pendimethalin) and 9% (triasulfuron + terbutryn) at their recommended doses. The results indicated that P. hysterophorus is the most susceptible to glyphosate and bromoxynil + MCPA, both these herbicides are very promising for the wilting and management of parthenium weed.

二甲戊灵和丙炔氟草胺对棉田一年生杂草的防治效果

【目的】分析评价二甲戊灵乳油(EC)与丙炔氟草胺可湿性粉剂(WP)单剂及其混配后对棉田一年生杂草的安全性和防治效果,为棉田杂草的化学防治提供科学依据。【方法】研究不同处理对棉田一年生杂草药后30 d株防效,45 d的株防效和鲜重防效,分析各处理药剂对棉花出苗的安全性。【结果】供试药剂对棉花出苗无影响,各处理出苗率与空白对照相比无显著性差异。330 g/L二甲戊灵EC(742.5 g/hm^(2))+50%丙炔氟草胺WP(45 g/hm^(2))和330 g/L二甲戊灵EC(866.25 g/hm^(2))+50%丙炔氟草胺WP(60 g/hm^(2))对棉田一年生杂草30 d株防效分别为96.52%和97.91%,45 d株防效分别为95.86%和96.48%,45 d鲜重防效分别为92.89%和94.44%,2种药剂混配后对棉田一年生禾本科、阔叶杂草均有较好的防治效果。330 g/L二甲戊灵EC 866.25~990 g/hm^(2)对棉田一年生禾本科杂草株防效和鲜重防效在83.58%~90.23%,50%丙炔氟草胺WP 60~75 g/hm^(2)的处理为84.58%~90.98%,二者差异不显著,该剂量下二甲戊灵对棉田一年生阔叶杂草株防效和鲜重防效在82.62%~88.90%,丙炔氟草胺的处理防效为85.06%~92.21%。【结论】丙炔氟草胺对棉田一年生阔叶杂草的株防效和鲜重防效优于二甲戊灵,可根据棉田优势杂草群落结构的差异选择不同的药剂施用,合理防治棉田杂草。

45%二甲戊灵·丙炔氟草胺微囊悬浮-悬浮剂对大蒜田一年生杂草的防效

为了明确45%二甲戊灵·丙炔氟草胺微囊悬浮-悬浮剂防除大蒜田一年生杂草的应用效果,2018年和2019年连续2年采用田间小区试验的方法开展了田间药效试验,研究了该药剂对大蒜田主要一年生杂草的防除效果以及对大蒜的安全性。结果表明,45%二甲戊灵·丙炔氟草胺微囊悬浮-悬浮剂防除大蒜田一年生杂草的田间推荐用量为789.75~1046.25 g/hm^(2)(有效成分用量),药后180 d对总草的株防效、鲜重防效可分别达到83.00%、86.42%以上。45%二甲戊灵·丙炔氟草胺微囊悬浮-悬浮剂对大蒜田一年生杂草播娘蒿、荠菜、繁缕、看麦娘均有较好的防除效果,且对大蒜安全,具有很好的省工效益。

40%砜吡草唑悬浮剂防除小麦田一年生杂草效果

为明确40%砜吡草唑悬浮剂(SC)对小麦田一年生杂草的防除效果与安全性,在小麦播后苗前选用40%砜吡草唑SC 375、450、750 mL/hm^(2)进行土壤封闭处理防除麦田杂草效果试验。结果表明,40%砜吡草唑SC 375、450、750 mL/hm^(2)封闭处理60 d后对阔叶杂草的株防效为100%,90 d后对阔叶杂草的株防效在97.39%及以上,130 d后对阔叶杂草播娘蒿、拉拉藤、小藜、葎草的株防效、鲜重防效分别在93.18%、96.73%及以上;对泽漆的株防效在81.00%~95.29%之间,鲜重防效达98.78%及以上。而该药剂对节节麦防效较差,药后130 d株防效、鲜重防效在53.81%~86.07%之间。不同的砜吡草唑处理对小麦产生了不同程度的药害,药后60 d小麦出苗率在77.65%~84.94%之间,药后90 d株高抑制率为2.96%~7.39%,分蘖抑制率为4.6%~24.0%,并且随着剂量的增加,药害呈加重趋势。农业生产中建议在防除旱茬麦田杂草时用40%砜吡草唑SC 375 mL/hm^(2)进行封闭处理,并避开低温多雨水的条件使用。

甲酰氨基嘧磺隆·甲基碘磺隆对夏玉米田杂草防除效果及其对产量的影响

设32%甲酰氨基嘧磺隆·甲基碘磺隆钠盐水分散粒剂14.4、22.8、31.2、45.6 g(a.i)/hm^(2)4个剂量,以30%甲酰氨基嘧磺隆水分散粒剂30 g(a.i)/hm^(2)为对照药剂,并设人工除草及空白对照,研究32%甲酰氨基嘧磺隆·甲基碘磺隆钠盐水分散粒剂对夏玉米田杂草防除效果及其对夏玉米产量的影响。在夏玉米播种后22 d、杂草2~6叶期进行茎叶喷药处理。于药后20、40、60 d分别监测杂草种群数量,同时取样分析杂草对养分的累积情况,并于夏玉米收获后进行测产。结果表明,施用32%甲酰氨基嘧磺隆·甲基碘磺隆钠盐水分散粒剂14.4~45.6 g(a.i)/hm^(2)对试验夏玉米田一年生杂草稗草[Echinochloa crusgalli(L.)Beauv]、马唐[Digitaria sanguinalis(L.)Scop]、旱莲草(Eclipta prostrata L.)、马齿苋(Portulaca oleracea L.)表现出较好的防除效果,药后60 d对稗草、马唐、旱莲草、马齿苋的株防效为79.82%~95.35%,对稗草、马唐、旱莲草、马齿苋的鲜重防效为81.75%~96.76%,与对照药剂30%甲酰氨基嘧磺隆水分散粒剂30 g(a.i)/hm^(2)对以上杂草的防效相当,供试药剂各处理对夏玉米的增产效果达20.70%~25.10%,显著优于空白对照和人工处理。32%甲酰氨基嘧磺隆·甲基碘磺隆钠盐水分散粒剂在使用过程中未发现药害,也未发现人畜中毒,对环境友好。

扑草净防除马铃薯田杂草药效试验

试验结果表明 ,5 0 %扑草净防除马铃薯田杂草 ,在用药量 0 .5～ 1.0kg/hm2 范围内 ,对马铃薯的生长发育影响较小 ,可有效地防除马唐、狗尾草、稗草、反枝苋、藜等一年生杂草。施药后 15d ,株防效为 97.7%～ 98.6 % ;施药后 4 5d ,株防效 88.8%～ 97.0 % ,鲜重防效 80 .6 %～ 92 .0 %。增产效果为 10 .3%～ 15 .2 %。最佳用药量以 0 .7kg/hm2 为宜 ,施药适期以杂草 2～

19%烟嘧磺隆·辛酰溴苯腈悬浮剂防除玉米田杂草效果及安全性研究

[目的]明确19%烟嘧磺隆·辛酰溴苯腈悬浮剂对玉米田一年生单、双子叶杂草的防除效果以及对玉米的安全性,并确定其最佳使用剂量。[方法]试验采用随机区组排列,设4次重复,对施药区进行安全性调查和防效调查,并采用DPS软件对防效调查结果进行Duncan氏新复极差法统计检验。[结果]19%烟嘧磺隆·辛酰溴苯腈悬浮剂4种剂量(228～570g/hm2)及25%辛酰溴苯腈乳油450g/hm2处理对玉米生长及抽穗无不良影响。施用19%烟嘧磺隆·辛酰溴苯腈悬浮剂228～285g/hm2能有效地防除玉米田一年生单、双子叶杂草。药后10d,对稗草、马唐、铁苋菜、苘麻、异型莎草等杂草的株防效为74.6%～87.6%,药后30d,株防效为91.2%～97.4%,鲜重防效91.3%～98.8%。[结论]19%烟嘧磺隆·辛酰溴苯腈悬浮剂防除玉米田杂草安全有效,最佳施药时间为3￣5叶期。

黄淮海地区夏玉米田一年生杂草的生态经济防治阈期研究

本文通过北京和唐山多年多点田间试验，研究了黄淮海地区夏玉米田苗后放任和免除自生一年生杂草生长的相对时间与夏玉米相对产量的函数关系，并据此导出了该区夏玉米田一年生杂草的生态经济防治阈期计算模型。结果发现，该区夏玉米田一年生杂草的生态经济防治阈期约处在夏玉米苗后总生育期的（天）第１１．２－５０．９％之间．核区夏玉米生长季节中只要此期田间保持无草，便可望以最小的代价和费用，最大限度地使杂草弃害扬利，从而获得较高的生态经济除草效益。

麦田越年生杂草及其化学防除技术的研究

河北省麦田有越年生杂草 2 0种 ,其中荠菜和播娘蒿为优势种。麦田越年生杂草绝大部分在秋季出苗 ,秋季出苗杂草是防除的重点。在以越年生杂草为主的麦田 ,改春施 2 ,4—滴丁酯为秋施 ,可省药 3/ 4左右 ,并可显著提高除草效果。对绿黄隆、甲黄隆和苯黄隆等进行了研究 ,明确了各自的杀草谱、杀草活性、对小麦和后茬作物的安全性以及施药适期、最佳用药量等应用技术 。

42%噁草酮·乙草胺EC对花生田一年生杂草的防除效果

为明确42％噁草酮·乙草胺EC对花生田一年生杂草的防除效果、最佳田间使用剂量及施药技术。田间药效试验结果表明：42％噁草酮·乙草胺EC对花生田一年生杂草有很好的防治效果，且在试验剂量下对花生安全，适宜的施用剂量为810-1080ga．i．／hm^2，兑水600L／hm^2。施药适期为花生播后苗前，施药方法为土壤喷雾处理，药后20天的株防效为91．7％～93．2％，药后40天的株防效为85．7％～87．7％，鲜重防效为82．1％～84．4％。

城乡梯度上一年生杂草叶片氮磷含量的变化及其与土壤氮磷的关系

在上海城乡梯度上,选取隶属于禾本科和菊科的3种广布型一年生杂草:狗尾草(Setaria viridis)、稗(Echinochloa crusgalli)和醴肠(Eclipta prostrata),通过测定3种杂草单位质量叶片氮含量、单位质量叶片磷含量及其生境中土壤总氮、总磷的含量,分析城乡梯度上植物叶片氮磷含量的变化及其与土壤氮磷之间的关系.结果表明:1总体上,从中心城区至远郊区,3种一年生杂草的叶片氮含量显著上升,而叶片磷含量无显著变化;2其中,狗尾草与醴肠的叶片氮含量呈显著上升趋势,狗尾草叶片磷含量呈显著上升趋势;3土壤总氮、总磷与植物单位质量叶片氮、叶片磷总量呈显著性负相关(p<0.05).综上可知,杂草的叶片氮磷含量对城市化有显著响应,物种间存在差异;土壤氮磷含量的变化是其成因之一.

12%烟嘧·氯氟吡油悬浮剂防除玉米田一年生杂草田间药效及安全性试验

验证了12%烟嘧·氯氟吡氧乙酸油悬浮剂的田间使用效果,在夏玉米苗后3～5叶期茎叶处理,施药后3d,玉米叶片上出现点状或块状黄斑,药后7d左右开始恢复,对玉米生长及结实无不良影响,对玉米安全。药后10d,12%烟嘧?氯氟吡氧乙酸油悬浮剂180、216、270、432ga.i./hm2对狗尾草、马唐、铁苋菜、苘麻、异型莎草等杂草总的株防效分别为74.3%、79.1%、81.2%、87.4%;药后30d,株防效分别为91.2%、92.8%、94.1%、97.4%,鲜重防效分别为91.3%、92.1%、96.3%、98.8%,对一年生杂草防效显著。

76%扑草净·乙草胺·噻吩磺隆乳油防除马铃薯田一年生杂草的效果及安全性

为明确76%扑草净·乙草胺·噻吩磺隆乳油对马铃薯田一年生杂草的防效及对马铃薯的安全性,采用随机区组试验设计方法进行了田间药效试验。在低剂量1 140 g a.i.·hm^-2下,药后20 d76%扑草净·乙草胺·噻吩磺隆乳油对一年生杂草的株总防效为89.16%;药后40 d对一年生杂草的株总防效为84.59%;药后55 d对一年生杂草鲜质量总防效为86.96%,较空白对照增产为19.51%。结果表明,76%扑草净·乙草胺·噻吩磺隆乳油对马铃薯田一年生杂草有较好的防治效果,对马铃薯安全,无药害发生,并具有一定的增产作用,是马铃薯田的一种较好的复配除草剂。

50%乙草胺乳油防除夏大豆田杂草药效试验

试验结果表明,50%乙草胺乳油防除夏大豆田杂草,在用药量1800～4200ml/hm2范围内,对大豆的生长发育影响较小,可有效地防除马唐、藜、反枝苋、马齿苋等一年生杂草。施药后30d,株防效达87.9%～98.8%;施药后45d,株防效达94.9%～98.6%,鲜重防效达67.0%～98.2%。增产效果为10%～14%。最佳用药量以2400ml/hm2为宜,施药适期以夏大豆播后1～2d为好。

200g/L氯氟吡氧乙酸乳油对玉米田一年生阔叶杂草药效及安全性试验

对200g/L氯氟吡氧乙酸乳油防除玉米田一年生阔叶杂草药效及安全试验进行了研究。结果表明,200g/L氯氟吡氧乙酸乳油750～1050ml/hm2能有效地防除玉米田一年生阔叶杂草。药后10d,750、900、1050ml/hm2氯氟吡氧乙酸乳油对反枝苋、马齿苋、鸭跖草等阔叶杂草的株防效分别为87.9%、90.9%、93.7%,药后30d,750、900、1050ml/hm2氯氟吡氧乙酸乳油株防效分别为94.7%、96.3%、98.1%,鲜重防效分别为95.7%、97.5%、99.1%,且对玉米安全性好。

吡嘧·丙草胺WP防除水稻田一年生杂草的效果及安全性

为明确55%吡嘧·丙草胺可湿性粉剂(WP)对水稻田中稗草、水苋菜、异型莎草、鳢肠、千金子的防效以及对水稻的安全性,进行防除水稻抛秧田一年生杂草的药效试验。结果表明:水稻抛秧后7~10 d用55%吡嘧·丙草胺WP 1 050 g/hm^2拌细潮土225 kg/hm^2人工撒施作土壤封闭处理,可以有效防除稗草、水苋菜、异型莎草、鳢肠、千金子,药后45 d株防效达88.33%,鲜质量防效达93.29%,对总杂草的防效均极显著高于对照药剂375 m L/hm^210%吡嘧磺隆WP、1 200 g/hm^230%丙草胺乳油单剂,对抛秧水稻安全。