4种茎叶处理除草剂对半夏田杂草的防除效果

为有效解决半夏田草害问题, 选择4种茎叶除草剂进行半夏田杂草防除田间药效试验。结果表明:10%乙羧氟草醚EC 50~60 mL/667m2 (制剂用量,下同)处理与240 g/L乳氟禾草灵EC 20~30 mL/667m2处理能有效防除半夏田金腰箭、辣子草、土荆芥、金荞麦、紫花香薷、针筒菜、尼泊尔蓼等阔叶杂草, 且对半夏安全, 药后21 d对阔叶杂草株防效、鲜重防效均达90%以上, 与禾本科除草剂8.8%精喹禾灵EC 40 mL/667m2或108 g/L高效氟吡甲禾灵EC 30 mL/667m2搭配使用对半夏田大部分杂草能实现较好防除。但两种阔叶除草剂持效期较短(30 d左右), 生产上可根据施药后期田间杂草发生情况, 采用人工拔除或进行第2次化学防除; 施药应避开中午高温时刻, 以免造成此类阔叶除草剂药害。研究结果可为半夏田除草剂的合理选择和应用提供科学依据。     

野燕枯防除高龄野燕麦田间试验初报

野燕枯防除高龄野燕麦田间试验初报李天银（甘肃省黄花农场农业试验站玉门７３５２１３）野燕枯是一种高效、低毒、选择性除草剂，主要用于麦田防除野燕麦。其作用在于叶面处理后，被心叶和嫩叶吸收，移动到分生组织，作用于生长点，破坏野燕麦的细胞分裂，使顶端和节间分...     

麦田杂草野燕麦的危害及防除

野燕麦（ＡｒｅｎａｆａｔｕａＬ．）别名：燕麦草、铃铛麦。为小麦伴生性杂草,在我省北部嫩江、依安、北安、德都等市县的国营农场以及牡丹江市危害面积较大,成为当地生产的障碍。一、形态特征一年生或越年生草本,株高８０～１２０厘米,茎直立,丛生或单生。叶鞘长于...     

野燕麦种子萌发特性及化学防除药剂筛选

为了明确恶性杂草野燕麦的萌发特性和化学防除技术,采用培养皿与盆栽相结合的方法,研究温度、光照、水势、盐胁迫、pH、土层深度对种子萌发的影响并评价麦田常用除草剂对野燕麦的除草活性。结果表明,野燕麦种子最适发芽温度为15~20℃。对光周期不敏感,全黑、全光照条件下均可正常萌发。当水势为-0.2~0 MPa时,发芽率可达80%左右,当水势降低至-0.8 MPa时,不能萌发。覆盖2~15cm的土层均可萌发,其中2~10cm土层中发芽率最高。适宜pH范围较广,在pH 5~9范围内,发芽率大于70%。耐盐胁迫能力较强,NaCl浓度160mmol/L时,发芽率大于50%。除草活性评价结果表明,炔草酯、唑啉草酯、精噁唑禾草灵、甲基二磺隆、氟唑磺隆、啶磺草胺对4~6叶期野燕麦均有较好防效,供试药剂防效高低排序为:炔草酯、唑啉草酯精噁唑禾草灵甲基二磺隆氟唑磺隆、啶磺草胺异丙隆。     

防除大豆田铁苋菜的茎叶处理除草剂筛选

铁苋菜（Acalypha australis L.）在黑龙江省大豆田的种群数量及其危害日益严重,农民已将其列为难防杂草。采用盆栽试验方法,筛选了防治铁苋菜的茎叶处理除草剂。结果表明,灭草松、噻吩磺隆、异噁草松、咪唑乙烟酸对2～6叶期铁苋菜无防除效果;防除2叶期铁苋菜,可以施用氟磺胺草醚300 g/hm2、乳氟禾草灵90 g/hm2、乙羧氟草醚60 g/hm2;防除4叶期铁苋菜,氟磺胺草醚施药量需高于300 g/hm2,乙羧氟草醚的施药量需高于90 g/hm2;防除6叶期铁苋菜,仅能施用氟磺胺草醚,且施药量需高于300 g/hm2。     

茎叶除草剂对刺萼龙葵的防治效果评价

采用茎叶喷雾法评价了7种防除阔叶杂草的除草剂对野外5～7叶期刺萼龙葵的防除效果。药后30d调查结果表明,7种除草剂对刺萼龙葵的生长均有一定的抑制作用,不同药剂对刺萼龙葵的防效差异显著。防除刺萼龙葵较好的药剂有48%三氯吡氧乙酸乳油、24%氨氯吡啶酸水剂和20%氯氟吡氧乙酸乳油,试验剂量下对刺萼龙葵的鲜重防效均在85%以上,25%氟磺胺草醚水剂对刺萼龙葵的防效较差。三氯吡氧乙酸、氨氯吡啶酸和氯氟吡氧乙酸能够有效防治刺萼龙葵,根据药剂的不同特性,探讨了在不同入侵地的应用可能性。     

14种茎叶处理除草剂防除田菁田龙葵效果及安全性评价

田菁是重要的绿肥植物和盐碱地改良植物,也是盐碱地重要的经济作物,杂草尤其是龙葵是影响其产量的重要因素。采用田间药效试验法,开展14种常用茎叶处理除草剂对田菁的安全性及防除龙葵的效果评价。试验结果表明,唑嘧磺草胺、甲咪唑烟酸对田菁安全性好,田间推荐剂量对龙葵的鲜重防效均在95%以上;丙炔氟草胺药后早期可引起田菁心叶略黄化,嗪草酸甲酯可造成田菁叶片触杀斑,但后期田菁均可恢复生长,安全性也较好,除丙炔氟草胺低剂量处理外,对龙葵的鲜重防效均在90%以上。其他药剂对田菁均有较重触杀性药害或抑制生长,对田菁不安全。另外,灭草松、乙氧氟草醚、三氟羧草醚对龙葵也有较好的防除效果,可登记用于田菁田防除龙葵。     

稻茬麦田野燕麦的发生危害特性与防除技术

稻茬麦田野燕麦的发生危害特性与防除技术张剑玲，张国林，朱凤生，汤志华，施惠芳，仇善明，毛玉群，桂国英（高邮市植保植检站２２５６００）（高邮市界首八桥农技站）近年来，野燕麦（ＡｕｅｎａｆａｔｕａＬ．）在本市不断扩展蔓延，危害水旱两熟制麦田，损失严重。自...     

茎叶处理型除草剂使用中应注意的问题

本文从喷雾器械、药液的理化性能和除草剂的组合使用方面概述了茎叶处理型除草剂使用中应该注意的问题。     

Reduced rates of residual and post-emergence herbicides for weed control in vineyards

In 1997 and 1998, five field studies were conducted at four Portuguese wine‐growing regions in order to evaluate the effectiveness of the chemical control of vineyard weeds under Mediterranean conditions using either reduced doses of residual herbicides or only foliar herbicides. Amitrole (3440 g a.i. ha^?1), amitrole + glyphosate mono‐ammonium salt (1720 + 900 g a.i. ha^?1), amitrole (3400 g a.i. ha^?1), amitrole + diuron (2580 + 1500 g a.i. ha^?1), amitrole + simazine (2580 + 1500 g a.i. ha^?1), amitrole + terbuthylazine (2580 + 1500 g a.i. ha^?1) and amitrole + diuron + simazine (2580 + 1300 + 1400 g a.i. ha^?1) were assayed and compared with the following reference herbicides: glyphosate isopropylamine salt (1800 g a.i. ha^?1), amitrole + diuron (2520 + 1680 g a.i. ha^?1), diuron + glyphosate + terbuthylazine (1275 + 900 + 1425 g a.i. ha^?1), amitrole + simazine (1900 + 3900 g a.i. ha^?1) and glyphosate + simazine (800 + 2200 g a.i. ha^?1). The herbicides were applied during late winter. The results indicated that good control was achieved by the application of foliar herbicides alone or of reduced rates of a mixture of residual herbicides with foliar herbicides for at least 2 months. Three months after application, the efficacy of post‐emergence herbicides and lower rates of residual herbicides decreased significantly in clay soils and under heavy rainfall conditions. Convolvulus arvensis– a weed that is becoming increasingly significant in Portuguese vineyards – was poorly controlled, even when glyphosate was used. Despite this, it can be assumed that in those regions in which the trials were conducted, it is possible to employ weed control strategies that entail the elimination or a reduction in the rate of residual herbicides.     

胡萝卜田苗后杂草化学防除药剂筛选

为探究安全、高效的胡萝卜田苗后杂草化学防除技术,采用盆钵法研究了13种苗后茎叶处理除草剂对胡萝卜的室内安全性,并对筛选得到的苗后除草剂进行了初步的田间药效及安全性试验。结果表明：供试13种除草剂中扑草净对胡萝卜的安全性较好,在225 g（a.i.）/hm²剂量下,胡萝卜苗的鲜重为53.61 g,与对照无显著差异,未出现药害反应;在450、750 g（a.i.）/hm²剂量下分别出现了1级和2级的低级别药害反应;而噁草酮、氰草津、嘧啶肟草醚、双草醚、辛酰溴苯腈、乙氧氟草醚、乙羧氟草醚、咪唑乙烟酸、灭草松、噻吩磺隆、双氟磺草胺和氯吡嘧磺隆在推荐剂量下,对胡萝卜鲜重抑制率为19.30%~100.00%,出现了3~5级的药害反应。扑草净对胡萝卜田杂草有较好的防效,在剂量为450~600 g（a.i.）/hm²时对胡萝卜田杂草总体的株防效和鲜重防效均达到80.56%以上,且对胡萝卜安全,无药害反应。胡萝卜田苗后杂草化学防除建议使用450~600 g（a.i.）/hm²扑草净进行茎叶喷雾处理,可达到对禾本科和阔叶杂草的有效防除,且对胡萝卜安全。     

3种茎叶处理除草剂在胡麻田的最佳施药期研究

为了筛选出对胡麻安全、对杂草防效优良的茎叶除草剂最佳喷施时期,田间测定了400 g/L 2甲·溴苯腈EC 1 500 mL/hm~2、56%2甲4氯钠SP 1 200 g/hm~2和40%2甲·辛酰溴EC 1 275 mL/hm~2在不同时期喷施对胡麻生长发育的影响及对田间杂草的防效。通过对胡麻株高、鲜重、产量及控草效果综合分析看出：400 g/L 2甲·溴苯腈EC在胡麻株高5 cm、56%2甲4氯钠SP在胡麻株高2.5～5 cm、40%2甲·辛酰溴EC在胡麻株高5～10 cm喷施,对胡麻株高的抑制作用均能在成熟期降至微弱或无影响,对胡麻鲜重的抑制作用均能提早减轻至微弱甚至无影响;胡麻生物产量分别较人工除草增加9.66%、-6.25%～-1.77%和7.19%～9.97%,胡麻籽粒产量分别较人工除草增加5.39%、-0.86%～-0.47%和-0.56%～5.45%;对阔叶杂草株防效分别达到81.82%、51.46%～73.88%和51.91%～67.21%,对阔叶杂草鲜重防效分别达到98.99%、88.96%～96.33%和91.26%～94.47%。可见,参试除草剂在上述时期喷施对...     

7种苗后除草剂对菵草的除草活性以及对小麦的安全性评价

为了筛选对菵草高效且对小麦安全的除草剂品种,采用温室盆栽法测定了 7种苗后除草剂对菵草的除草活性以及对小麦的安全性.结果表明,5％唑啉草酯EC和15％炔草酯WP对菵草防效优异,ED90仅为各自田间登记低剂量的1/3和1/2;50％异丙隆WP和7.5％啶磺草胺WG对菵草防效较好,ED90与各自田间登记高剂量相当;69 g...     

Genetic diversity of herbicide-resistant and -susceptible Avena fatua populations in North Dakota and Minnesota

Genetic diversity within and among 20 herbicide-resistant (HR) and 16 herbicide-susceptible (HS) Avena fatua multi-field populations was determined using 82 polymorphic loci resulting from two intersimple sequence repeat (ISSR) primers and one long-primer random amplified polymorphic DNA (LP-RAPD) primer. Collections from the Red River Valley of North Dakota and Minnesota, sampled in 1964 and 2000, represented A. fatua populations before and after intensive exposure to herbicides. A 1995 collection from south-west North Dakota represented A. fatua exposed to low herbicide selection. Despite differences in years of herbicide exposure among collections, both HR and HS populations from every collection maintained nearly similar levels of ISSR and RAPD diversity. Genetic differentiation among populations (G_ST) varied from 11% to 13% among HR populations and from 9% to 16% among HS populations, indicating that 84–91% of total variation remained within HS or within HR populations. Minimal difference in gene diversity between HR and HS is consistent with multiple origins of resistance, where HR A. fatua most likely evolved from diverse founding individuals.     

81.5%乙草胺乳油防除春油菜田野燕麦效果

81.5％乙草胺乳油993.87 g/hm2,在春油菜播种前兑水300 L/hm2进行土壤喷雾处理,对野燕麦防效达73.63％,对作物安全,油菜增产8.06％.     

几种除草剂对胡麻田裸燕麦(莜麦)、皮燕麦的防除效果

本文开展了唑啉草酯等7种除草剂对胡麻田裸燕麦、皮燕麦的防除试验研究,结果表明,在胡麻株高5~7cm,裸燕麦、皮燕麦3~5叶期施药,50g/L唑啉草酯乳油、108g/L高效氟吡甲禾灵乳油、15%精吡氟禾草灵乳油、240g/L烯草酮乳油和10%精喹禾灵乳油有效成分剂量分别为90、145.8、315、432和90g/hm2时,药后45d对裸燕麦的株防效达95.39%以上,鲜重防效达97.21%以上,胡麻增产率在82.79%以上;50g/L唑啉草酯乳油、108g/L高效氟吡甲禾灵乳油、15%精吡氟禾草灵乳油、15%炔草酯可湿性粉剂、10%精喹禾灵乳油和12.5%烯禾啶乳油有效成分剂量分别为90、145.8、270、135、90和412.5g/hm2时,药后45d对皮燕麦的株防效在94.66%以上,鲜重防效达96.13%以上,胡麻增产率在80.25%以上,各药在上述剂量下防治裸燕麦和皮燕麦后均对胡麻表现安全,可大面积示范推广。     

Biochemical mechanisms of cross-resistance to aryloxyphenoxypropionate and cyclohexanedione herbicides in populations of Avena spp.

Aryloxyphenoxypropionate (APP) and cyclohexanedione (CHD) herbicides are used extensively in the UK to control grass weeds, including Avena spp. (wild-oats). Reports of resistance to APP and CHD herbicides are a particular concern for the agricultural community. In this study, the responses of four UK Avena populations were characterized towards the APP herbicides fenoxaprop-P-ethyl and fluazifop-P-butyl, and towards the CHD herbicides cycloxydim and tralkoxydim. An A. sterilis ssp. ludoviciana population (T/41) was found to be highly resistant to fenoxaprop-P-ethyl and fluazifop-P-butyl, but did not show cross-resistance to cycloxydim and tralkoxydim. In contrast, one A. sterilis ssp. ludoviciana (T/11) and one A. fatua population (Dorset) showed partial resistance to both APP herbicides and also showed cross-resistance to the CHD herbicide tralkoxydim, but not to cycloxydim. Before this study, the biochemical mechanisms that confer resistance to the APP and CHD herbicides in UK Avena populations were unknown. Results from the present study show that an enhanced rate of metabolism of fenoxaprop-P-ethyl was found to confer resistance in the two partially resistant Avena populations (T/11 and Dorset), and the presence of an insensitive form of the target enzyme, ACCase, was responsible for target site resistance to fenoxaprop-P-ethyl and fluazifop-P-butyl in the highly resistant population T/41. Cross-resistance to the CHD herbicide tralkoxydim in the T/11 and Dorset populations was not conferred by insensitive ACCase, and was most probably caused by enhanced metabolism. This is the first report that resistance to fenoxaprop-P-ethyl can be conferred by enhanced metabolism in Avena spp.