丙环唑对水稻纹枯病菌的抑制作用及对纹枯病的防治效果

为明确丙环唑对水稻纹枯病的防治作用,通过离体抑菌试验,温室盆钵试验和田间试验研究了丙环唑对水稻纹枯病菌的抑制作用和对纹枯病的防治效果.离体抑菌试验表明,丙环唑能够强烈抑制水稻纹枯病菌(Rhizoctonia solani)的菌丝生长,EC50为0.045 μg/mL,并能够强烈抑制菌核产生,但不能抑制菌核萌发.温室试验表明,纹枯病菌经丙环唑处理后,致病力随药剂浓度提高而显著减弱;丙环唑可以很好地被水稻叶片和根系吸收,并输送到水稻的茎部和叶鞘;丙环唑对水稻纹枯病具有保护和治疗作用,400 μg/mL丙环唑处理水稻,抑制病斑长度分别达到82.16％和76.61％,并随药剂处理浓度的降低而降低;丙环唑对立枯丝核菌有较长的持效期,800 μg/mL处理水稻11 d后再接种的防效为40.10％.田间药效试验表明,25％的丙环唑乳油在有效剂量150 g/hm2下3次喷药后14 d的防效达到89.15％,丙环唑在本试验剂量范围内对水稻安全.表明丙环唑对水稻纹枯病有很好的防治作用,可为生产上防治水稻纹枯病和科学用药提供依据.     

3%苯醚甲环唑悬浮种衣剂防治小麦全蚀病试验

田间药效试验表明,3%苯醚甲环唑悬浮种衣剂以400～600 mL/100 kg种子包衣可以提高小麦出苗率,减少种子用量。苯醚甲环唑5006、00 mL/100 kg种子和(苯醚甲环唑500 mL+咯菌腈200 mL)/100 kg种子包衣小麦种子对小麦全蚀病的防效、产量指标和持效期均优于三唑酮。     

药剂拌种结合土壤处理对小麦全蚀病的防效

选用5种种衣剂分别拌种,结合播前以20%三唑酮乳油处理土壤,在河南博爱开展小麦全蚀病防治试验,调查各药剂处理的安全性、防治全蚀病的效果以及对产量的影响。结果表明,使用3%苯醚甲环唑悬浮种衣剂处理麦种防治小麦全蚀病的效果最优:处理后的小麦出苗整齐、生长健壮、未见药害;拔节期病株防效为98.62%,乳熟期白穗防效为92.04%;处理区小麦产量较清水对照区增加54.37%,均为各处理中最高。     

小麦全生育期土传病害科学防控实践

为有效防治小麦全生育期土传病害,分别在小麦播种期、返青期采用不同的用药方案开展了田间防治示范。结果表明,播种期用27%苯醚甲环唑·咯菌腈·噻虫嗪悬浮种衣剂、31.9%戊唑醇·吡虫啉悬浮种衣剂、11%吡唑醚菌酯·灭菌唑悬浮种衣剂、23%苯醚甲环唑·咯菌腈·吡虫啉悬浮种衣剂拌种,结合返青期喷施430 g/L戊唑醇悬浮剂、30%苯甲·丙环唑乳油、125 g/L氟环唑悬浮剂,收到了较好的应用效果,不仅可有效控制小麦茎基腐病、纹枯病,降低白穗率,还可以有效提高小麦产量,增产率达14.61%～21.43%。     

小麦根病化学防治技术研究

经１９９１－１９９５年室内、田间试验、筛选出丙环唑、三唑酮等三唑类杀菌剂为防治小麦根病的有效药剂。这类内吸性的杀菌剂不仅对小麦根的致病一蚀病菌和麦根腐离蠕孢菌毒力强,且对小麦生长有良好的调节作用。可降低小麦育苗株高,促进根系发育,提高纪苗根比、增强根系活力,增加单位重叶片叶绿素含量。在各试验处理中,以２５％丙环唑ＥＣ拌种加苗期喷洒白穗防效高达９８．４％。改变药剂剂型和处理方法,延长药效,且提高防效     

用硫磺熏杀双钩异翅长蠹

现将试用粉锈宁拌种防治小麦白粉病的情况报道如下 按播种量的0.015％、0.02％、0.03％粉锈宁(有效成分25％下同)拌种;按播种量的0.02％粉锈宁拌种,小麦灌浆期用25克/亩喷雾防治1次;小麦挑旗、灌浆期各用25克/亩喷雾防治1次以及清水对照6个处理。小区面积20米~2、3次重复。冬前、返青,乳     

苯醚甲环唑·丙环唑300g/L乳油防治小麦白粉病试验效果

田间试验表明,药后14d,苯醚甲环唑·丙环唑300g／L乳油对小麦白粉病防效达75．49％,增产效果达36．47％,优于常规药剂三唑酮处理;丙环唑250g/L乳油对小麦白粉病防效达64．53％,增产效果达27．30％,低于常规药剂三唑酮处理。     

立克秀拌种防治小麦纹枯病和全蚀病试验研究

１９９６～１９９７年分别在自然病地和土壤混合接菌条件下,应用立克秀６％悬浮种衣剂和２％湿拌剂拌种进行防治小麦纹枯病和小麦全蚀病试验,结果表明：立克秀悬浮种衣剂以１００ｋｇ麦种拌５０ｍＬ、６７ｍＬ,湿拌剂按种子重量０．２％拌种和对照药剂１０％三唑醇可湿性粉剂按种子重量０．４％拌种４个处理防效显著;尤以立克秀悬浮种衣剂６７ｍＬ／１００ｋｇ种子拌种防效最高,对纹枯病平均防效５０．７６％～６４．０３％,对全蚀病平均防效４５．２０％,增产幅度为１６．１３％～２２．１３％。而立克秀悬浮种衣剂较湿拌剂防病保产效果更为突出。立克秀拌种比三唑醇拌种安全性高,对小麦生长和发育无不良影响。     

不同杀菌剂拌种防治小麦全蚀病研究

为筛选防治小麦全蚀病的高效安全药剂,对多种杀菌剂在不同浓度下的防效以及对小麦的安全性进行了盆栽试验.结果表明,硅噻菌胺和苯醚甲环唑在推荐浓度下对小麦全蚀病有很好的防治效果,并且对小麦出苗、苗高没有显著影响;咯菌腈的防效与苯醚甲环唑相似,但对小麦出苗有轻微的抑制作用;其他几种杀菌剂对小麦全蚀病也能起到很好的防治效果,但是对小麦的生长有一定的抑制作用.从防治效果、对小麦安全性以及抗药性治理方面综合考虑,将硅噻菌胺、苯醚甲环唑和咯菌腈等交替或混合使用是防治小麦全蚀病比较好的策略.     

几种杀菌剂对草莓白粉病的防效研究

在温室大棚用苯醚甲环唑、苯醚甲环唑+丙环唑、氟硅唑、腈菌唑和三唑酮等杀菌剂防治草莓白粉病Sphaerotheca aphanis。结果表明,适宜浓度的 10%苯醚甲环唑WG、30%苯醚甲环唑+丙环唑EC、40%氟硅唑EC、20%三唑酮EC、12.5%腈菌唑EC的田间防治效果均可达到80%以上;苯醚甲环唑、苯醚甲环唑+丙环唑、氟硅唑和三唑酮的持效期约为18 d,而腈菌唑的持效期较短,约为7 d。10%苯醚甲环唑WG在360~900 g/hm2用量时不影响草莓长势,而氟硅唑225 mL/hm2和三唑酮300~450 mL/hm2用量时则在不同程度上抑制草莓的生长。     

水稻窄条斑病及其种子传病与药剂防治

水稻窄条斑病是浙江杭州地区的新病害,本研究从症状识别、种子传病及防治药剂测试三方面入手对该病害进行研究。结果表明,通过对光观察病斑透明度,观察有无菌脓及喷菌现象可有效地将水稻窄条斑病与水稻细菌性条斑病区分开;水稻窄条斑病种子可带菌传病,传病率因品种和种子来源不同而异;25%丙环唑EC和50%多菌灵WP对水稻窄条斑病均有较好防效,其中以25%丙环唑EC有效成分用量150g/hm2为最佳,防效达68.73%。     

300 g/L苯甲·丙环唑乳油对花生网斑病的田间防效

为明确300g/L苯甲·丙环唑乳油对花生网斑病的田间防治效果以及对植株主要农艺性状和产量的影响,本文进行了300g/L苯甲·丙环唑乳油不同施药次数、不同施药浓度以及与生长调节剂混用配施对花生网斑病的田间防效试验。结果表明,300g/L苯甲·丙环唑乳油3 000倍施药3~5次田间防效无显著差异,均可达到67%以上;采用稀释浓度1 500倍和3 000倍从发病初期开始连续施用3次防治效果较好,防效分别为71.19%和67.90%;300g/L苯甲·丙环唑乳油与植物生长调节剂混配试验结果表明,3 000倍液于花生网斑病发生初期配施0.136%赤·吲乙·芸苔8 000倍液1次,随后每隔10d喷施300g/L苯甲·丙环唑EC 1次,连续施药2次,其防治效果高于其他处理,为78.28%;同时具有显著增产作用,较对照增产47.45%。     

Sensitivity of fungi from cereal roots to fluquinconazole and their suppressiveness towards take-all on plants with or without fluquinconazole seed treatment in a controlled environment

The take-all fungus, Gaeumannomyces graminis var. tritici , was highly sensitive to fluquinconazole ( in-vitro EC₅₀ 0·016–0·018 mg L⁻¹), a fungicide developed for use as a seed treatment to control take-all, and to prochloraz (EC₅₀ 0·006 mg L⁻¹). Fungi of other genera that were commonly isolated from cereal roots were sensitive in varying degrees to prochloraz but were relatively insensitive (e.g. Fusarium culmorum , EC₅₀ > 20 mg L⁻¹) or slightly sensitive (e.g. Epicoccum purpurascens , EC₅₀ 0·514 mg L⁻¹) to fluquinconazole. Gaeumannomyces graminis var. graminis and G. cylindrosporus , weak parasites that can protect roots against take-all, and an unnamed Phialophora sp., all closely related to the take-all fungus, were highly or moderately sensitive to fluquinconazole. Alternaria infectoria and E. purpurascens were most consistently effective in suppressing development of take-all on pot-grown wheat plants dual-inoculated with G. graminis var. tritici and the nonpathogen. Take-all was decreased more on dual-inoculated wheat plants grown from seed treated with fluquinconazole or fluquinconazole plus prochloraz than when only an antagonistic fungus ( A. infectoria , E. purpurascens , Fusarium culmorum or Idriella bolleyi ) or a seed treatment was applied. These fungi were less effective in combination with seed treatments on barley. Gaeumannomyces graminis var. graminis and G. cylindrosporus , tested on wheat, suppressed take-all only in the absence of fungicides. It is suggested that the performance of seed treatment containing fluquinconazole against take-all may in some circumstances be enhanced by its partial specificity for the take-all fungus.     

Application of Pseudomonas fluorescens isolates to wheat as potential biological control agents against take-all

Two isolates of Pseudomonas fluorescens (2–79 and 13–79) from the USA were evaluated in the UK as biological control agents against Gaeumannomyces graminis var. tritici , the cause of take-all in wheat. Biological control agents were applied as seed coatings in carboxymethyl cellulose (CMC) to seven wheat trials sown in 1987 and 1988 on fen peat and clay soils, and as peat-based and microgranule formulations in one of these trials. In a trial of spring wheat on fen peat, all treatments with biological control agents reduced the percentage take-all infection of crown roots and seminal roots, but the effects of only one isolate were statistically significant ( P <0·05). Effects of biological control agents on infection rates in five other trials were not significant. In the trial in which application methods were compared, peat-based inoculum initially appeared most effective but none of the treatments reduced take-all significantly throughout the season. Application of biological control agents was associated with yield increases in several trials; these were not consistently associated with effects on take-all. These results suggest that the isolates of P. fluorescens have potential to reduce take-all and increase yields of wheat in the UK, but the beneficial effects are inconsistent. There is a need to develop isolates which reliably control severe take-all in a variety of soil types.     

Variation in the effects of take-all disease on grain yield and quality of winter cereals in field experiments

Relationships between take-all intensity and grain yield and quality were determined in field experiments on cereal crops using regression analyses, usually based on single-point disease assessments made during anthesis or grain-filling. Different amounts of take-all were achieved by different methods of applying inoculum artificially (to wheat only) or by using different cropping sequences (in wheat, triticale or barley) or sowing dates (wheat only) in crops with natural inoculum. Regressions of yield or thousand-grain weight on take-all intensity during grain filling were similar to those on accumulated disease (area under the disease progress curve) when these were compared in one of the wheat experiments. Regressions of yield on take-all intensity were more often significant in wheat than in the less susceptible crops, triticale and barley, even when a wide range of disease intensities was present in the latter crops. The regressions usually had most significance when there were plots in the severe disease category. Thousand-grain weight and hectolitre weight usually responded similarly to total grain yield. Decreased yield was often accompanied by a significant increase in the percentage of small grains. When severe take-all was present in wheat, regressions showed that nitrogen uptake was usually impaired. This was sometimes accompanied, however, by increased percentage nitrogen in the grain as a consequence of smaller grain size with decreased endosperm. Significant effects of take-all, both positive and negative, on Hagberg falling number in wheat sometimes occurred. Significant regressions of yield on take-all assessed earlier than usual, ie during booting rather than grain-filling in wheat and triticale and during anthesis/grain-filling rather than ripening in barley, had steeper slopes. This is consistent with observations that severe disease that develops early can be particularly damaging, whilst the crops, especially barley, can later express tolerance by producing additional, healthy roots. The regression parameters, including maximum potential yield (y-axis intercept) and the extrapolated maximum yield loss, also varied according to the different growing conditions, including experimental treatments and other husbandry operations. These differences must be considered when assessing the economic potential of a control measure such as fungicidal seed treatment.     

30%苯甲·丙环唑乳油防治水稻纹枯病田间药效

选用减量控害30%苯甲·丙环唑乳油与常规对照20%井冈霉素SP防治纹枯病进行药效对比试验,评价试验药剂30%苯甲·丙环唑对纹枯病的防治效果。试验结果表明,30%苯甲.丙环唑乳油药剂对纹枯病有较好的防效,平均防效达84.14%,比对照20%井冈霉素平均防效79.52%提高4.62%;减量控害区产量比常规用药增产31.2 kg/u,增产6.28%。减少施药用工2.5元/u,增加效益62.9元/u。建议使用时,用30%苯醚甲环唑.丙环唑30 mL/u对水45 kg/u于纹枯病发生盛期对水稻叶面均匀喷雾（全文设u=667 m2,单位面积）。     

Yield Trends during Take-all Decline in Spring Barley and Wheat Grown Continuously1

The effects of take-all, nitrogen and cropping sequence on grain yield were compared for spring barley and spring wheat grown in extended monoculture. Initial crops showed least take-all and maximum yields. Yields fell to a minimum more rapidly in wheat than in barley while the take-all intensity increased to a maximum; take-all decline occurred and yields improved from the 4th and 5th years respectively. Without nitrogen, yields were at their lowest level; application of nitrogen increased yields considerably with responses in proportion to the rate applied. At optimum rates, yield losses were 33% for wheat and 11% for barley with maximum disease intensity but only 9% and 3% respectively with take-all decline. Potential maximum yields in the absence of take-all were calculated to be greater with barley than with wheat.     

枯草芽胞杆菌YB-05对小麦全蚀病菌胞内酶活的影响

小麦全蚀病菌是影响小麦产量和质量的主要致病菌之一,前期研究表明枯草芽胞杆菌YB-05对小麦全蚀病菌的生长具有抑制作用。本试验拟通过研究该菌对小麦全蚀病菌相关酶系的诱导变化情况,解析其对小麦全蚀病菌的抑制作用机理。本试验以小麦全蚀病菌Gaeumannomyces gramini（Sacc.）Arx et Oliver var. tritici（Sacc.）Walker为靶标菌,加入终浓度为MIC₅₀枯草芽胞杆菌YB-05发酵液,通过显微镜观察菌株YB-05发酵液对小麦全蚀病菌菌丝结构和形态的影响,通过酶活力测定检测菌株YB-05发酵液对小麦全蚀病菌胞内苯丙氨酸解氨酶（PAL）、过氧化物酶（POD）、过氧化氢酶（CAT）、多酚氧化酶（PPO）和超氧化物歧化酶（SOD）防御酶活的影响,同时检测菌株YB-05发酵液在离体/活体条件下对小麦全蚀病菌线粒体复合酶Ⅱ/Ⅲ活力的影响。小麦全蚀病菌经菌株YB-05发酵液处理后,显微镜观察到其菌丝变粗、断裂,顶端膨大,分枝增多;处理8 d后,胞内的PAL、POD、CAT、PPO和SOD活性比对照依次高24.52%、72.67%、81.81%、80.36%和112.48%;离体条件处理,线粒体复合酶Ⅱ和Ⅲ的活性与对照组相比差异不显著,而活体条件处理下差异显著,线粒体复合酶Ⅱ和Ⅲ分别比对照组分别降低43.95%和55.87%。菌株YB-05发酵液通过结合小麦全蚀病菌线粒体复合酶Ⅱ和Ⅲ的相关基因,从而影响该基因的表达,抑制小麦全蚀病菌线粒体复合酶Ⅱ和Ⅲ的活力,影响小麦全蚀病菌的呼吸,进而导致抑制小麦全蚀病菌菌丝畸变,从而影响小麦全蚀病菌的正常生长。     

Tank-mix adjuvants and pesticide residues: some regulatory and quantitative aspects

Although it is well known that judicious use of adjuvants can increase the performance of foliage-applied sprays of many agrochemicals, little information is available in the public domain about their ultimate effects on pesticide residues in treated crops. In the present work, the influence of Agral (polyoxyethylene nonylphenols), Toil (methyl esters of rapeseed fatty acids) and Bond (styrene-butadiene copolymers) on surface and crop residues of diclofop-methyl/diclofop and propiconazole in wheat and field beans was investigated using a model system simulating field practice. Pesticides were applied as commercial formulations, diclofop-methyl 378 g litre(-1) EC (Hoegrass) and propiconazole 250 g litre(-1) EC (Tilt), at their maximum approved rates, 1135 g AI ha(-1) and 125 g AI ha(-1), respectively, both in the presence or absence of the maximum rate recommended for each candidate adjuvant. No detectable residues of diclofop-methyl or propiconazole were found in wheat 35 days after any of the four applications. However, residues of diclofop were present in this crop, and those from applications containing Agral (0.07 mg kg(-1) fresh weight (FW)) or Bond (0.08 mg kg(-1) FW) were significantly lower than those with no adjuvant (0.14 mg kg(-1) FW) or Toil (0.16 mg kg(-1) FW). Unlike wheat, residues of both diclofop and propiconazole were detected in field beans after harvest. Significantly higher residues of the former were recorded from the applications with Agral or Bond (ca 0.32 mg kg(-1) FW) than with those with no adjuvant or Toil (ca 0.15mg kg(-1) FW). All the propiconazole applications containing adjuvants showed a similar significant increase in residues (0.10-0.16 mg AI kg(-1) FW) over the no-adjuvant treatment (0.05 mg kg(-1) FW) in this crop. There appeared to be little agreement between the apparent amounts of uptake, as indicated by the rates of decline of surface residues up to 5 days after application, and final residues in either target species. On wheat, surface residues of diclofop-methyl decreased from initially ca 20 to as little as 0.02 mg kg(-1) FW using adjuvants; the corresponding values for propiconazole were ca 2 to ca 0.03 mg kg(-1) FW. Recoveries of diclofop-methyl from the surfaces of field beans were much higher than those from wheat, declining from ca 30 to only ca 6 mg kg(-1) FW during the course of 5 days; the corresponding residues for propiconazole were ca 2 mg to 0.15 mg kg(-1) FW. These findings are discussed in relation to uptake results obtained with radiolabelled pesticides and adjuvants in the laboratory, and to the mandatory requirements for pesticide residue data for the authorised use of adjuvants in the UK.     

吡虫啉拌种控制全生育期小麦蚜虫有效剂量评价

本文对吡虫啉拌种控制全生育期小麦蚜虫有效剂量进行了研究。结果表明,仅用吡虫啉拌种就可在小麦整个生育期将小麦蚜虫控制在防治指标之下,表现出超高效、持效的控制效果。1 kg种子用1.0~4.8 g吡虫啉（有效成分）拌种,从播种至灌浆末期,防治效果在95%以上,至乳熟期（收获期）防治效果仍高达74.49%~96.61%;千粒重比未拌种区增加了26.51%~36.55%。综合以上试验结果,吡虫啉拌种控制全生育期小麦蚜虫的经济、有效剂量为有效成分1.0~2.0 g/kg种子,最佳剂量为1.5 g/kg种子。