外来入侵杂草意大利苍耳

意大利苍耳(Xanthium italicum Moretti.)为菊科苍耳属一年生草本植物,原产美洲。本文对意大利苍耳的形态特征、生物学特性、分布及危害进行了叙述。     

外来入侵恶性杂草牛筋草的化学防除药剂评价筛选

牛筋草是全球危害最严重的5种杂草之一,为了筛选防除牛筋草的高效除草剂品种,采用温室盆栽法和田间小区试验测定了10种苗后除草剂对牛筋草的除草活性及防除效果。盆栽试验结果表明,30%苯唑草酮SC和40 g/L烟嘧磺隆OD对牛筋草防效优异,ED₉₀分别为8.7 g/hm~2和19.4 g/hm~2(有效成分,下同),约为各自登记低剂量的1/3和1/2。100 g/L氰氟草酯EC、10%噁唑酰草胺EC、69 g/L精噁唑禾草灵EW、120 g/L烯草酮EC和10%精喹禾灵EC对牛筋草具有较好的防效,ED₉₀分别为68.9、80.5、50.0、54.2 g/hm~2和48.6 g/hm~2,与各自的登记低剂量相当或略低。25%啶嘧磺隆WG和11%三氟啶磺隆OD对牛筋草的防效较差,ED₉₀分别为115.0 g/hm~2和112.4 g/hm~2,约为各自登记高剂量的1.5倍和2.3倍。75%硝磺草酮WG对牛筋草的防效很差,ED₉₀为742.6 g/hm~2,是其登记高剂量的3.3倍。田间试验结果表明,40 g/...     

2种苍耳属入侵植物在宁夏的分布

苍耳属(Xanthium L.)植物具有较强的入侵性,对农林业生产有较大的影响.为有效防治和控制刺苍耳(X.spinosum)和意大利苍耳(X.italicum)在宁夏的入侵态势,对这2种植物在宁夏的入侵情况、分布状况、生长情况进行了调查研究.结果表明,刺苍耳在宁夏地区以同心县为中心,形成了严重的入侵危害,并开始向周边...     

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。     

油菜田杂草药剂防除技术

油菜田杂草是影响油菜产量和品质的重要因素之一。选择合适的除草剂品种,采用安全高效的使用技术,科学合理地施用到杂草的有效部位,达到除草、保苗、增产、增收的目的。     

中山局截获检疫性杂草——意大利苍耳

2007年8月31日,中山口岸从日本的旧履带式挖掘机上截获1粒杂草种子,经中山出入境检验检疫技术中心植检实验室鉴定,并经广东检验检疫技术中心植检室复核,确认为我国进境植物检疫有害生物——意大利苍耳(Xanthinm italicum Moretti)。     

加拿大一枝黄花药剂防除对比试验

用10％甲磺隆可湿性粉剂、10％草甘膦水剂、20％使它隆乳油（氟草定）等3种药剂对加拿大一枝黄花进行防除试验。确定3种药剂在生产中防除拿大一枝黄花的适宜剂量和使用方法。     

不同药剂防除加拿大一枝黄花试验总结

加拿大一枝黄花为入侵性恶性杂草。用41%农达200倍液＋20%使它隆500倍液、48%可灵达200倍液、41%农达200倍液防除,均具有持效期长、防效好的特点。     

蔗田杂草发生危害及药剂防除

通过对广西东南部红黄壤区20个乡镇蔗田杂草调查明确,广西贵港蔗田杂草种类有152种,分属32科,其中菊科27种,占总数17.76％,其次是禾本科22种,占总数14.47％,其他依次为莎草科、苋科、大戟科、锦葵科等。蔗田杂草发生危害的特点是种类多、密度大、生长量大、前期生态控制作用小。药剂芽前土壤处理试验结果表明,F6285有效量30 g／667 m²、啶嘧磺隆3.3 g／667 m²、禾耐斯90 g／667 m²,药后40 d杂草株防效和鲜重防效均在86.5％以上,显著高于都尔、莠去津。药剂茎叶处理试验结果表明,阿·敌有效量140 g／667 m²、阿灭净有效量130 g／667 m²、啶嘧磺隆有效量3.3 g／667 m²+展着剂885.22.5 g／667 m²,药后30 d株防效和鲜重防效均可达到78.5％以上。     

油菜田杂草的发生特点及防除药剂筛选

2000～2001年我们进行了油菜田杂草的田间消长规律观察及不同药剂防除油菜田杂草的田间试验，现将调查及试验结果报告如下。     

Chemical composition and phytotoxic activity of the volatile oil of invasive Xanthium italicum Moretti from Xinjiang, China

Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish,implying that this invasive plant could release biologically active volatile organic compounds(VOCs)into the environment to affect other plants' growth.This phenomenon was further studied by evaluating the phytotoxic effects of X.italicum essential oil against two dicot plants,amaranth(Amaranthus mangostanus L.)and lettuce(Lectuca sativa L.),and two monocot plants,wheat(Triticum aestivum Linn)and ryegrass(Lolium multiforum),and analyzing the chemical composition of the oil.Among the 4 test species,amaranth was the most sensitive plant,0.5μl/mL essential oil application resulted in a 50% reduction on root elongation,and 2.5 μl/mL essential oil almost completely inhibited its seedling growth.Wheat was the least sensitive species,whose root growth was reduced to 36% of control by 5 μl/mL essential oil.The essential oil exerted moderate inhibitory effect on both lettuce and ryegrass.Compared to a commercial herbicide-Harness,X.italicum oil exhibited stronger phytotoxicity on amaranth,lettuce and wheat,but weaker activity on ryegrass.The chemical composition of the essential oil isolated by hydrodistillation from the aerial parts of X.italicum Moretti was analyzed by GC/MS.Thirty two compounds were identified,representing 94.89% of total oil,which was found to be rich in monoterpene hydrocarbons(60.71%).The main constituents of the oil were limonene(51.61%),germacrene B(6.98%),δ-cadinol(5.94%),β-pinene(5.23%),α-caryophyllene(5.1%)and bornyl acetate(3.15%).Bioassay revealed the dominant constituent-limonene,was unlikely the responsible phytotoxic compound due to its low biological activity;rather,there might be other oil constituent(s)that either act alone,or work together,and possibly assisted by synergistic effect,to display the phytotoxic activity.Our results suggested that X.italicum might produce allelopathic VOCs to facilitate its invasion success.This is the first report on the phytotoxic activity and the chemical composition of the essential oil of X.italicum Moretti from China.     

The present status of biological control of Xanthium (Compositae)

Abstract

The economic threshold level of the mustard aphid, Lipaphis erysimi (Kaltenbach) was determined on the radish seed crop, var Punjab Sufed. Spraying oxydemeton methyl at 300 g a.i./ ha, was monitored at arbitrary set aphid levels from 25 to 150 aphids/plant. The maximum cost benefit ratio (1: 13.1) was achieved at an aphid level of 50 per plant, requiring three sprays. Spraying in the middle of February was the most crucial, as delay of 7 days from this stage resulted in significant decreases in yield in the fixed spray schedule and at the 75‐aphid level.     

Toxicity of fenpropimorph to fenarimol-resistant isolates of Penicillium italicum

Fenarimol-resistant isolates ofPenicillium italicum with cross-resistance to imidazole and triazole fungicides which inhibit ergosterol biosynthesis were tested for their sensitivity to fenpropimorph. Radial growth tests on PDA showed that the isolates (n=6) lacked cross-resistance to fenpropimorph or displayed enhanced sensitivity to the fungicide (negatively correlated cross-resistance). Control of blue mold decay of oranges incited by the wild-type isolate could be achieved by dipping fruits in suspensions of fenpropimorph at a concentration of 100 mg ml^–1. Decay of oranges incited by the fenarimol-resistant isolates was controlled at the same or at a lower concentration (30 mg ml^–1), thus showing that the normal or increased sensitivity to fenpropimorph is also expressed under in vivo conditions.Samenvatting Fenarimol-resistente isolaten vanPenicillium italicum met kruisresistentie tegen imidazool-en triazoolfungiciden die de ergosterolbiosynthese remmen, werden getoetst op hun gevoeligheid voor fenpropimorf. Radiale groeiproeven op PDA toonden aan dat de isolaten (n=6) geen kruisresistentie bezaten met fenpropimorf of een verhoogde gevoeligheid voor het middel vertoonden (negatief gecorreleerde kruisresistentie). Op sinaasappels konPenicillium-rot, veroorzaakt door het wild-type bestreden worden door middel van een dompelbehandeling met fenpropimorf bij een dosering van 100 g ml^–1). Bestrijding van rot veroorzaakt door fenarimil-resistente isolaten werd verkregen bij dezelfde of een lagere dosering (30 g ml^–1); aldus werd aangetoond dat de normale of verhoogde gevoeligheid voor fenpropimorf ook in vivo tot uiting komt.     

苍耳属植物生物活性研究进展

在医学方面,苍耳(Xanthum sibiricum Patrin.)成熟带总苞的果实(俗称苍耳子),具有抗炎、抗过敏、抗氧化、抗组胺、抗乙酰胆碱及抗血小板活化因子等药理作用,临床上常用于治疗风寒头疼、鼻渊流涕、风疹瘙痒等.在植物保护方面,苍耳属植物具有杀虫、抑菌、杀线虫和抑制杂草生长作用.     

苍耳杀线虫活性的初步研究

通过温室盆栽试验研究了苍耳叶5种溶剂提取物对番茄根结线虫(Meloidogyneincognita)的活性。结果表明,苍耳叶5种溶剂提取物均有一定的杀线虫活性,其中丙酮与甲醇提取物120mg干粉/mL的防治效果最佳,分别为75.54%和73.83%。不同溶剂对苍耳叶的提取率间存在明显差异,且这种差异与不同溶剂提取物杀线虫活性间的差异之间存在一定相关性。同时苍耳叶提取物对番茄生长具有一定的抑制作用。     

Stepwise development of laboratory resistance to DMI-fungicides in Penicillium italicum

Isolates ofPenicillium italicum with differential levels of resistance to imazalil were obtained via step-wise mass selection of conidia of the fenarimol-resistant isolate E300-3 on imazalilamended PDA. Three out of five selection steps were successful. The resistance level to imazalil of isolates acquired after the two last selection steps was on average 122 and 197. The differential level of resistance was also apparent in decay control on oranges by imazalil inoculated with the various isolates. The isolates showed a similar cross-resistance pattern to other fungicides which inhibit C-14 demethylation of sterols (DMIs), although the level of resistance to these fungicides was significantly higher. All isolates displayed negatively-correlated cross-resistance to tridemorph and dodine. Most isolates had a normal virulence on oranges. In competition experiments with mixed-inocula of the wild-type and a resistant isolate, the proportion of the wild-type increased in successive generations on untreated oranges and the proportion of the resistant isolate increased on imazalil-treated oranges. The lower competitive ability of the resistant isolate on untreated oranges may be due to a decrease in spore production as compared with the wild-type.Since isolate E300-3 was obtained in two selection steps on fenarimol-amended PDA, the isolates obtained in the last selection steps on imazalil-amended PDA may have at least five different genes for resistance to DMIs. This is consistent with resistance to DMIs being under polygenic control, with the genes involved having an additive interaction, although this is not the only possible explanation of the results.     

Metabolism of imazalil by wild-type and DMI-resistant isolates of Penicillium italicum

Metabolism of imazalil (1-[2-(2,4-dichlorophenyl)-2-(2-propenyloxy)ethyl]-1H-imidazole) inPenicillium italicum isolates with a wild-type sensitivity and with various degrees of resistance to sterol demethylation inhibitors was studied in liquid cultures. The metabolite 1-[2(2,4-dichlorophenyl)-2-(2,3-dihydroxypropyloxy)ethyl]-1H-imidazole (R42243) was detected in the culture filtrate after prolonged incubation. The metabolism occurred in the propenyl side chain of imazalil probably through epoxidation and hydratation. This is the first report of such a conversion of imazalil in fungi. R42243 was much less toxic toP. italicum than imazalil. Therefore, the metabolism can be regarded as a detoxification step. Both wild-type and resistant isolates metabolized imazalil, but metabolism by resistant isolates was faster than by the wild-type isolate. This is probably caused by a relatively strong inhibition of growth of the wild-type isolate by the fungicide. Results indicate that the detoxification of imazalil does not operate as a mechanism of resistance. This conclusion was confirmed by the fact that resistant isolates showed cross-resistance to miconazole and R42243, which had a similar structure as imazalil except for the propenyl side chain.     

Evaluation of food additives and low-toxicity compounds as alternative chemicals for the control of Penicillium digitatum and Penicillium italicum on citrus fruit

The effectiveness of low-toxicity chemicals as possible alternatives to synthetic fungicides for the control of post-harvest green and blue moulds of citrus was evaluated. A preliminary selection of chemicals, mostly common food additives, was made through in vivo primary screenings with oranges artificially inoculated with Penicillium digitatum or P italicum. Selected compounds and mixtures were tested as heated solutions in small-scale trials. Immersion of artificially inoculated oranges or lemons for 120 s in solutions at 40.6 degrees C and natural pH of potassium sorbate (0.2 M), sodium benzoate (0.2 M) or mixtures (0.1 + 0.1 M) of potassium sorbate with sodium benzoate, sodium propionate or sodium acetate were the most effective organic acid salts tested and reduced green mould by 70-80% after 7 days of storage at 20 degrees C. The mixtures did not significantly enhance the effectiveness of potassium sorbate or sodium benzoate alone. These solutions were as effective as sodium carbonate or calcium polysulphide treatments and, in general, they were more effective on lemons than on oranges. Satisfactory control of green and blue moulds was obtained by dipping oranges for 150 s in solutions of sodium molybdate (24.2 mM) or ammonium molybdate (1.0 mM) at 48 or 53 degrees C, but not at 20 degrees C. At 53 degrees C, however, the effectiveness of hot water was not enhanced by either molybdate. Molybdenum salts at higher concentrations were phytotoxic and stained the fruit. At non-phytotoxic concentrations, the effectiveness of these solutions was more influenced by temperature than by concentration. In general, the inhibitory effects of all compounds tested were not fungicidal but fungistatic and not very persistent. In conclusion, potassium sorbate, sodium benzoate and ammonium molybdate, among the wide range of chemicals tested, were superior for the control of post-harvest Penicillium decay of citrus fruit.     

Effect of nicosulfuron on plant traits of Xanthium strumarium

Journal of Plant Diseases and Protection - Field experiments were conducted in 2008 and 2009 at the Experimental Field Institute Padinska Skela PKB Agroe-konomik, near Belgrade, to quantify effects...