240克/升烯草酮乳油防除夏大豆田杂草田间药效试验

田间试验结果表明,夏大豆田播后苗期使用240克/升烯草酮乳油30～40克/667m2,对禾本科杂草有较好的防除效果,并且有较长的持效期,对大豆生长安全。     

烯草酮防除油菜田禾本科杂草效果

烯草酮为油菜田禾本科杂草除草剂,对禾本科杂草株防效可达90%以上,对油菜安全,增产效果显著。对阔叶杂草无效。     

二氯吡啶酸防除春油菜田刺儿菜和苣荬菜的效果

30%二氯吡啶酸(毕克草)600 ml/hm2,对春油菜田刺儿菜的防效为84.59%,对苣荬菜的防效为80.99%以上,油菜平均增产13.02%.     

20%烯草酮·草除灵悬浮剂防除免耕移栽油菜田间药效试验

20%烯草酮·草除灵悬浮剂是丰乐农化公司新开发的油菜田除草剂,主要用于免耕移栽油菜田茎叶处理。为探讨该药剂在低温条件下,对移栽油菜田杂草的防除效果及对油菜的安全     

16%草除灵·二氯吡啶酸·烯草酮SC防除移栽油菜田杂草的效果

16%草除灵·二氯吡啶酸.烯草酮SC对移栽油菜田一年生禾本科杂草及阔叶杂草的防效良好。在试验剂量180～480 g a.i./hm2下对移栽田油菜安全,不影响油菜的生长和发育。其适宜的施用剂量为240～480g a.i./hm2,施药适期为油菜3～5叶期、杂草3～4叶期,使用方法为叶面均匀喷雾。     

24%烯草酮乳油防除冬油菜禾本科杂草试验

油菜是夹江县的主要油料作物,常年种植面积0.8万hm~2。油菜田的禾本科杂草看麦娘、早熟禾是农民防除的主要对象。24％烯草酮乳油系防除禾本科杂草的内吸型茎叶除草剂。我站于2002年进行了24％烯草酮乳油防除冬油菜禾本科杂草试验,现将结果总结于后:     

二氯吡啶酸防除春油菜田刺儿菜和苣荚菜的效果

30％二氯吡啶酸（毕克草）600ml／hm^2,对春油菜田刺儿菜的防效为84．59％,对苣荬菜的防效为80．99％以上,油菜平均增产13．02％。     

120g/L烯草酮乳油防治春大豆田杂草田间药效试验

120g/L烯草酮乳油是丰乐农化公司新开发的油菜田除草剂,该药剂为内吸传导型高选择性苗后除草剂,可迅速被植物叶片吸收,并传导到根部和生长点,抑制植物支链脂肪酸的生物合成,被处理的植物体生长缓慢并丧失竞争力,幼苗组织早期黄化,随后其余叶片萎蔫.导致杂草死亡.     

油草克防除移栽油菜田杂草的效果

油草克防除移栽油菜田杂草的效果张青，李沛元，杨荣明（江苏太湖地区农科所苏州２１５１５５）油菜是苏南地区重要的经济作物，仅苏州市常年种植面积就达１００万亩以上。杂草是影响油菜产量的重要因子，特别是近年来该地区广泛推广免耕移栽技术，造成油菜与杂草共生期拉...     

丙炔噁草酮防除马铃薯田杂草效果初报

选用80％丙块噁草酮WP进行了苗前1次性防除马铃薯田杂草试验,调查了丙炔噁草酮的药效.结果表明,在马铃薯出苗后30 d丙炔噁草酮对杂草的株防效为62.0％～98.6％,对杂草鲜重的抑制率为68.8％～98.5％,马铃薯增产6％以上.试验剂量内各处理均对马铃薯安全,无药害.     

高效氟吡甲禾灵防除春油菜田野燕麦的效果

10.8%高效氟吡甲禾灵EC300 ml/hm2,于油菜2~5叶期,野燕麦2~5叶期喷雾,防除野燕麦效果达90%以上,对油菜安全,增产达35%以上。     

First report of target-site resistance to ACCase-inhibiting herbicides in Bromus tectorum L.

Background

The prevalent and repeated use of acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicides for Bromus tectorum L. control in fine fescue (Festuca L. spp) grown for seed has selected ACCase-resistant B. tectorum populations. The objectives of this study were to (1) evaluate the response of nine B. tectorum populations to the ACCase inhibitors clethodim, sethoxydim, fluazifop-P-butyl, and quizalofop-P-ethyl and the acetolactate synthase (ALS) inhibitor sulfosulfuron and (2) characterize the resistance mechanisms.

Results

Bromus tectorum populations were confirmed to be resistant to the ACCase-inhibiting herbicides tested. The levels of resistance varied among the populations for clethodim (resistance ratio, RR = 5.1–14.5), sethoxydim (RR = 18.7–44.7), fluazifop-P-butyl (RR = 3.1–40.3), and quizalofop-P-ethyl (RR = 14.5–36). Molecular investigations revealed that the mutations Ile2041Thr and Gly2096Ala were the molecular basis of resistance to the ACCase-inhibiting herbicides. The Gly2096Ala mutation resulted in cross-resistance to the aryloxyphenoxypropionate (APP) herbicides fluazifop-P-butyl and quizalofop-P-ethyl, and the cyclohexanedione (CHD) herbicides clethodim, and sethoxydim, whereas Ile2041Thr mutation resulted in resistance only to the two APP herbicides. All B. tectorum populations were susceptible to sulfosulfuron (RR = 0.3–1.7).

Conclusions

This is the first report of target-site mutations conferring resistance to ACCase-inhibiting herbicides in B. tectorum. The results of this study suggest multiple evolutionary origins of resistance and contribute to understanding the patterns of cross-resistance to ACCase inhibitors associated with different mutations in B. tectorum. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Diaspore characteristics and ecological adaptation of Bromus tectorum L. from different distribution regions

The invasion of nonnative plants is considered one of the main threats to the structure and function of North American ecosystems.Moreover,they can alter ecosystem processes and reduce biodiversity.In arid and semi-arid region of North America,the species of European annual grass Bromus tectorum L.is an outstanding example of these problems,which not only increase the fire density and change the fire regime,but replace native communities.Therefore,there are amount of researches on B.tectorum,including resource acquisition,water use efficiency and growth.Whereas the relevant research on the morphology of diaspore is scare.Diaspores have a fundamental role in seed germination and seedling establishment.Besides,as an important link between different generations,diaspores have a vital significance on individual reproduction and population extension.Hence,diaspores under selection for studying have an important implication.This study compares differences in seed morphology for Bromus tectorum collected from the United States,Kazakhstan,and Xinjiang of China.The following indices of B.tectorum diaspores were analyzed:size,thickness of covering layers,and micromorphological characteristics of the base,middle and transition area of diaspores as well as of the awn.Micromorphology of the lemma and the cross-section of the diaspore were observed by scanning electron microscopy.Results showed that thickness of the lemma and the palea of diaspores from B.tectorum-infested grasslands in the United States were reduced(P<0.05),likely because of environmental influences.This reduction facilitated the germination of diaspores and lowered the resistance of B.tectorum to adverse environmental conditions.The length of the awn also increased significantly(P<0.05),which helped in dispersal and anchoring of diaspores.Therefore,B.tectorum adapted ecologically to its new environment in the United States by strengthening its establishment ability.However,the defense capability of B.tectorum decreased.These results fit the evolution of increased competitive ability hypothesis(EICA)of invasive species.Analysis of various cells on the lemma revealed that prickle densities and collapsed,long epidermal cells were easily influenced by environmental factors such as temperature and moisture because of the physiologic function of these structures on silicon accumulation.However,the form and the position of silica cells,which were not greatly influenced by environmental factors,might be genetically controlled.Studying these structures at the microscopic level helps define the relationship between the diaspore and its environment.This study has a reference value for future studies on B.tectorum.     

Effect of nitrogen and phosphorus on growth and interference between Bromus tectorum and Taeniatherum asperum

The effects of nitrogen and phosphorus supply on growth and interference between Bromus tectorum and Taeniatherum asperum were studied in greenhouse sand culture, using a modified replacement series experiment. Three levels of N and P were applied in all possible combinations. Height, number of leaves and biomass production were reduced in both species in response to nutrient reduction. B. tectorum had higher dry matter production than T. asperum at high nitrogen or phosphorus concentrations' or when both nutrients were present. When either nutrient was lacking, yield of both species was similarly reduced. Nitrogen deficiency was more influential on yield reduction than phosphorus in both species. In mixtures, B. tectorum was highly competitive at high concentrations of N and P. At lower levels of N and P supply, the species performed equally. Early patterns of resource allocation and high growth rates in B. tectorum enable that species to outperform T. asperum at high nutrient concentration. These advantages were reduced by nutrient deficiency, which led to competitive equality between the species. Effet de l'azote et du phosphore sur la croissance et l'interaction entre Bromus tectorum et Taeniatherum asperum Les effets de la fourniture en azote et en phosphore sur la croissance et l'interaction entre Bromus tectorum et Taeniatherum asperum ont étéétudiés en cultures de serre sur sable, à l'aide d'un dispositif en séries de remplacement modifié. Trois niveaux de N et P étaient appliqués dans toutes les combinaisons possibles. Chez les deux espèces, la hauteur, le nombres de feuilles et la production de biomasse étaient réduits en réponse à une diminution des nutriments. A haute concentration d'azote ou de phosphore, ou quand les deux nutriments étaient présents, B. tectorum produisait davantage de matière sèche que T. asperum. Quand l'un des nutriments était absent, le rendement des deux espèces était réduit de manière similaire, l'effet d'une déficience en azote étant le plus marqué. En cultures mélangées, B. tectorumétait hautement compétitif a fortes concentrations de N et P. A plus basses concentrations, les deux espèces présentaient les mêmes performances. L'allocation de ressources aux stades précoces et la vitesse de croissance élevée de B. tectorum lui permettaient de supplanter T. asperum lorsque la fourniture en nutriments était importante. Cet advantage était réduit lorsque la fourniture en nutriments était plus faible, ce qui conduisait à une égalité des pouvoirs compétitifs. Die Wirkung von Stickstoff und Phosphor auf das Wachstum und die Konkurenz zwischen Bromus tectorum und Taeniatherum asperum In einem substitutiven Versuchsansatz auf Sandboden im Gewächshaus wurde die Wirkung der Stickstoff- und Phosphorversorgung (in 3 Düngungsstufen) auf Wachstum und Konkurrenz von Bromus tectorum und Taeniatherum asperum untersucht. Pflanzenhöhe, Blattzahl und Biomasseproduktion waren bei beiden Arten entsprechend der abnehmenden Düngung reduziert. Bei hohem Stickstoff- oder Phosphorniveau oder bei Gegenwart beider Nährstoffe hatte B. tectorum eine stärkere Trockenmassebildung als T. asperum. Fehlten beide Nährstoffe, so war bei beiden Arten das Wachstum ähnlich herabgesetzt. Stickstoffmangel wirkte sich bei beiden Arten stärker aus als Phosphormangel. In Mischbeständen war B. tectorum bei hohen N- und P-Konzentrationen sehr konkurrenzkräftig. Bei niedriger Nährstoffversorgung verhielten sich die Arten gleich. Aufgrund frühzeitiger Nährstoffaneignung und hoher Wachstumsraten übertrifft B. tectorum bei hoher Nährstoffversorgung die anderere Art. Bei Nährstoffmangel gibt es diesen Vorteil nicht, so daß beide Arten gleich konkurrenzstark sind.     

Characterisation of a triazine-resistant biotype of Bromus tectorum found in Spain

A population of Bromus tectorum infesting an olive grove at Córdoba (Spain) survived simazine use rates of 3.0 kg a.i. ha⁻¹ over two consecutive years. Non‐tillage olive monoculture and two annual simazine applications had been carried out for 10 years. The resistant biotype showed a higher ED₅₀ value (7.3 kg a.i. ha⁻¹) than that of the susceptible control (0.1 kg a.i. ha⁻¹), a 73‐fold increase in herbicide tolerance. The use of fluorescence, Hill reaction, absorption, translocation and metabolism assays showed that simazine resistance in this biotype was caused by a modification of the herbicide target site, since chloroplasts from the resistant biotype of B. tectorum were more than 300 times less sensitive to simazine than those from the susceptible biotype. In addition, non‐treated resistant plants of B. tectorum displayed a significant reduction in the Q_A to Q_B electron transfer rate when compared with the susceptible biotype, a characteristic that has been linked to several mutations in the protein D1 conferring resistance to PS II inhibiting herbicides. Resistant plants showed cross‐resistance to other groups of triazine herbicides with the hierarchy of resistance level being methoxy‐s‐triazines ≥chloro‐s‐triazines > methylthio‐s‐triazines > cis‐triazines. The results indicate a naturally occurring target‐site point mutation is responsible for conferring resistance to triazine herbicides. This represents the first documented report of target site triazine resistance in this downy brome biotype.     

除草剂老铁防除油菜田杂草的效果

40%老铁WP为乙草胺与扑草净的复配制剂,登记主要用于春大豆、春小麦、玉米、棉花等旱作物地防除杂草.为明确老铁在油菜田的除草效果、杀草谱、使用剂量及对油菜的安全性,我们进行了小区试验.     

不同药剂控制油菜田杂草效果

油菜是吴江市主要经济作物,常年种植面积均在13000hm2以上。自20世纪90年代以来,由于长期单一使用精禾草克防治看麦娘,导致油菜田杂草草相发生了明显变化,以繁缕为主的双子叶杂草上升为主要优势种,给油菜生产带来了威胁。为了寻找适合于吴江市目前油菜田杂草草相的安全、高效新     

10%百除EC防除水稻田双穗雀稗试验报告

双穗雀稗 (ＰａｓｐａｌｕｍｄｉｓｔｉｃｈｕｍＬ .)是一种重要的湿生性杂草 ,近年在苏北沿海农场稻田的发生面积迅速扩大 ,给水稻生产构成严重威胁。由于 2 0世纪90年代中期以来我场逐步推广机插秧、抛秧等水稻轻型栽培技术 ,水浆管理方法发生改变 ,同时疏忽了对农渠边埂杂草的防除 ,使得双穗雀稗在我场迅速蔓延 ,危害日益严重。为有效地控制该杂草 ,我们引进了江苏省农业科学院苏科实验农药厂研制的10 %百除ＥＣ(有效成分为氰氟草酯和精恶唑禾草灵 ) ,在农场五大队一中队Ｎ13 条田进行该药剂防除双穗雀稗的效果和对水稻的安全性试验 ,现…     

Joint effects of biotic and abiotic stressors on winter wheat suppression of Bromus tectorum

In winter wheat systems in the Northern Great Plains of the United States, Bromus tectorum and wheat streak mosaic virus (WSMV) commonly co‐occur. While independent effects of these pests on wheat yields have been well documented, to our knowledge, no study has investigated whether WSMV modifies interactions between wheat and B. tectorum. Furthermore, the impact that environmental stressors such as nutrient availability have on these interactions has not been addressed. We conducted a randomised split‐plot field study over 2 years to investigate the effects of WSMV and nitrate (N) availability on winter wheat suppression of Bromus tectorum. The study included four N treatments (10–19, 20–31, 31–84, and 85–207 kg ha^?1) and two WSMV treatments (mechanically inoculated or control). Increasing soil N increased the susceptibility of wheat to WSMV infection. In 2009, wheat in the lowest and highest N levels had 24% and 65% of plants infected respectively. However, regression analysis indicated that interactive effects of wheat competition, N and WSMV did not play a consistent role in B. tectorum growth. Specifically, the effect of both wheat density and distance from row on B. tectorum biomass remained constant across inoculation treatments, suggesting that wheat inoculated with WSMV suppressed B. tectorum as effectively as healthy wheat. Furthermore, wheat had a greater impact on B. tectorum growth in higher N environments, even though incidence of WSMV infection in wheat was highest. Overall, our results suggest that WSMV infection may not change the ability of wheat to suppress B. tectorum.     

青海省旱雀麦生物学特性及其发生危害与防除

旱雀麦(Bromus tectorum L.)为禾本科1年生杂草.其适应性强,繁殖系数高,传播途径广,蔓延速度快.青海省生产上应用野麦畏、高效氟吡甲禾灵有效控制了野燕麦危害后,放松了对农田禾本科杂草的管理.