应用敌百虫防治荔枝蝽象的大田试验

荔枝蝽象是华南地区的重要害虫之一。作者根据此虫自然抗药性季节变化的規律,結合荔枝的开花結果时期,采用有机磷杀虫剂敌百虫0.067％水溶液噴雾于3月中及5月初各噴药一次,防治效果达95％以上。基本可以消灭荔枝蝽象成虫及若虫的为害,达到保花保果的要求。根据試驗結果,掌握上述两个时期大面积噴敌百虫,对荔枝开花、結果以及品质,均无不良影响。噴药时最好暫时关閉蜂箱,噴药后再放蜂。大面积使用敌百虫防治荔枝蝽象,成本低廉,每株药剂及人工費用为0.177元,每亩15株計算,每亩費用为2.65元。防治时期,最好选择能在3—4天內天晴、气温较高、风力0—1級为宜,噴雾要求均匀周到。     

小麦条锈病药剂防治试验

1962年和1963年,分别在信阳和郑州进行三次田间药剂防治小麦条銹病試驗結果表明:在叶面防治效果方面,超过0.5％对氨基苯磺酸10％以上的有0.5％与0.3％“閩农五号”、氟化鈉600倍、1000倍、氟矽酸鈉600倍、1％氨基苯磺酸鈉、1％氨基苯磺酸鋅、1％氨基苯磺酸鎳、0.1％与0.2％氮化鎳、0.2％氟化鎳及0.2％醋酸鎳等12种;超过1—10％或基本上相等的有1％常州氟鋇、1％氨基苯磺酸铁、0.1％与0.2％硫酸鎳四种;其中药效較好而又无药害、比对照增产10—35％的有1％氨基苯磺酸鈉、0.5—1％常州氟鋇、0.3—0.5％“閩农五号”、0.5％氨基苯磺酸铁及0.5％对氨基苯磺酸等;药效尚好而药害輕微、比对照增产10—20％的有1％氨基苯磺酸铁盐、0.5％鋅盐、0.5％鎳盐、0.1％醋酸鎳及氟矽酸鈉600倍等。田間药剂防治的适当时期和次数,根据病情动态和噴药效果分析,在河南省中南部地区建議以小麦的孕穗初、孕穗末或抽穗初、揚花期三次噴药为最好,灌浆以后噴药一般不起作用,如早春气温较高,病情上升迅速,則可在拔节期加噴一次。     

油茶炭疽病的综合防治

1962—1963年在四川省泸县地区进行油茶炭疽病的防治試驗。結果表明:采用营林措施(修除树上病部)和化学保护(噴射1∶1∶150波尔多液)的综合防治方法,病株防治效果可达89.77％,防止果病率达70.02％。严重病区,可在冬(12月)、春(2月)修除病部各一次(或可集中在2月进行),发病期間(4—8月)噴射波尔多液8—10次(条件不許可山区,也至少5次)。噴药宜連續性。上述措施,应进行2—3年。     

“苏化911”防治稻纹枯病的研究

根据紋枯病的特点,确定防治以化学保护为主,寻找有效药剂并探討其施用方法。室內試驗,在测定的81种药剂中,阿莫尼亚、多硫化鋇、西力生、磺原酸鋅、硝酸銀及多种有机錫等都有很好的杀菌作用,但在大田应用时,由于药力不能持久,都无实际效果。五氯硝基苯效果不稳定,在适于发病的环境下卽无效。土习脫有高效,但其成分复杂,且药害严重,难于广泛应用。只有“苏化911”有很好的防病效果,而无显著的药害。經过連續三年间在南京等地示范試驗結果,用100—200 p.p.m.在水稻孕穗前噴布一次卽可将稻株的发病率从82.6—100％压低到6.2—0％,产量視病情的輕重增加6.3—49.2％。“苏化911”也有一定药害,但如使用方法适当,也可以減免。“苏化911”的合理用法:1.剂型:“苏化911”不溶于水,必須制成乳剂或悬浮液作噴布用或用填充物稀释作撒布用。在喷布时必須使用适当的噴雾器,使药液均匀分佈稻株表面。在撒布时,虽徒手操作,也可得到如期效果。撒布药土的效果較之噴粉、噴雾毫无逊色。使用毒土浓度虽高达1000 p.p.m.,仍无明显药害。2.浓度:初步看出用30％可湿性“苏化911”粉剂1份加滑石粉100份或者加风干細土300份已有满意的效果。在嘖雾时乳剂或可湿剂浓度均以100—200p.p.m.为宜。3.用量:100p.p.m.的乳剂或悬浮液,每公頃施用1500公升,可奏全效,而无药害,如用量增加,最好減低浓度,否則有严重药害。4.使用时期:以水稻生育前期(分蘖末到孕穗初)为宜,过迟,特别抽穗以后效果小,且对产量不利。5.用药次数:“苏化911”的残效可以持續数十天,噴布一次就能收到完全或近完全的效果。     

春玉米田除草防治小地老虎的研究

两年来試驗研究和大面积防治調查資料表明:在小地老虎一龄盛期时(4月25日左右),田間杂草(小薊)密度大、栖食的幼虫数量多,当幼虫尚未向玉米上迁移之前,充分发揮除草的作用,可以減少田间虫群密度,減輕玉米受害。小地老虎一龄盛期是除草防治的最适时期。适期除草防治的效果与撒6％六六六毒土和噴5％二二三粉剂的防治效果不相上下,4月下旬除草減少死苗(断茎),效果达到45.83—58.5％,除草結合噴药有增效作用,減少死苗效果达到73.9％。除草防治具有农业防治的优点,經济有效、簡单易行。     

铜氨合剂对柑桔溃疡病的防治效果

从1986～1988年我们连续3年用铜氨合剂(自配),农用链霉素(750ppm),新植霉素(750ppm),1％石灰倍量式波尔多液4种药剂在柑桔苗木(椪柑苗2720株和锦橙苗1240株),成龄柑桔树(1987年,8年生雪柑成龄树36棵,1988年,4年生锦橙成龄树32棵)上进行药剂试验,试验时均设对照和重复。喷药时间和次数为:柑桔苗木在夏秋2次梢抽出时各喷3次药,每隔7～10天喷一次药;成龄树1987年于6月30日80％夏梢抽出时喷第一次药,8月11日80％秋梢抽出时喷第2次药,共喷2次;1988年于5月28日,6     

石硫合剂防治大青枣白粉病试验初报

为探索大青枣白粉病节本增效绿色防治技术,以0．7°Be、05Be、0．3Be 3种不同波美度石硫合剂及常用杀菌剂15％三唑酮WP1000倍液、70％甲基托布津WP1000倍液进行了田间防治试验。结果表明,0．7°Be石硫合剂平均防效达93．53％,防效最高,除与0．5。雎石硫合剂处理差异不显著外,与其它处理防效有着显著...     

福州柑桔溃疡病的发生规律

1.柑桔潰瘍病在福州自4月上旬至11月上旬均可发生,而以5、6、7月为发病高峯。 2.旬平均温度16.6—30.6℃,相对湿度68—91.4％都适于发病,而以旬平均温度22.2—30.6℃,相对湿度70.9—91.4％发病較高。 3.雪柑和晚生橙新梢在接近成长时开始发病,刚停止伸长、叶尚浅綠或开始革质化时发病率最高,至老熟时则抗病。果实横径1—1.5厘米(落花后約20天)开始发病,横径2.4—3.4厘米时(落花后60—80天)发病率最高,停止长大、果色转黄后抗病。 4.噴药保护新梢,应掌握新梢在成长达2/3至刚达成长的期間:春梢約在萌芽后40—50天;夏梢約在萌芽后20—40天;秋梢約在萌芽后30—60天。噴药保护果实,可在全部落花后10天开始,在幼果形成后50—70天更应注意保护。     

苹果内吸磷残留量的动态酶化学研究

用Hestrin胆硷酯酶活性测定法,系統研究以不同方式施用内吸磷(E-1059)后,苹果内吸磷残留量的动态变化情况。施药方式有三种:(1) 浸果—仅对树上的苹果进行药浸,树叶和树枝不接触药液。(2) 噴叶—苹果以塑料膜包好后向树上嘖药,只树叶和枝上着药,而苹果不着药。(3) 浸枝——将带有果和叶的一段树枝剪下,断端浸入药液中迫使吸收药液24小时。检测結果:浸果施药后第一天内,苹果可检测出很高的内吸磷残留量(可达2 ppm左右),1天后残留量降到0.75 ppm以下,两周后残留量可降低到接近零;噴叶施药后12天内,經数次检测,均未发现有内吸磷残留;用药液浸枝,虽然第一天树枝吸收了不少的药液,但苹果中几乎检測不出内吸磷的残留,第二天换以水浸枝,却反而检测出内吸磷残留量(将及0.5 ppm),大約10天左右残留量降到接近零。試驗結果说明:一般噴雾时内吸磷的残留主要是由于药液直接接触苹果果皮所致,通过叶和枝内吸輸导至苹果上的药液是微乎其微的;浸果施药后第一天内残留量最高,以后逐漸降低,約两周后降到接近于零;浸枝时迫使吸入药液,但輸导至苹果上的药物甚少,并且内吸輸导需要一定时間,所以第二天残留量最高。关于苹果施用内吸磷的期限,似乎可职适当后延至收获前3或4周。     

乐果防治柑桔瘤壁虱效果好

防治柑桔瘤壁虱,过去普遍用石灰硫磺合剂,但不能杀死瘿内的成虫和若虫,用E-1059喷雾或刮皮涂干又不够安全。1964年3月我们在四川金堂赵镇进行了乐果防治试验。     

Efficacy of aerial application ofBacillus thuringiensis to controlSpodoptera littoralis (Lepidoptera, Noctuidae) infesting soybean cultivations in Egypt

The calculated percentage of droplets deposition ofBacillus thuringiensis var.kurstaki HD-1 Dipel 2X on the foliage of soybean plants in relation to the sensitive “Ciba Geigy” papers showed to be the highest (92.4%) after ground spray application, compared to an average of 67.4, 85.8 and 89.3% following aerial application of the same preparation in spray volumes of 10, 20 and 30 l/F, respectively. Aerial application ofB. t. showed to be more effective during the first 3 days after spraying soybean cultivations and the mortality ofSpodoptera littoralis larvae varied between 36.9–67.2% in correlation to the spray volume. The volume achieving the highest and significant suppression of infestation was 20 l/F. On the other hand, the yield of soybeans obtained from plots receiving a spray volume of 30 l/F was higher compared to plots sprayed with a volume of 20 or 10 l/F, but with no significant difference when compared to those plots receiving ground spray application.     

Relationship between the Spray Droplet Density of Two Protectant Fungicides and the Germination of Mycosphaerella fijiensis Ascospores on Banana Leaf Surfaces

The effect of fungicide spray droplet density (droplet cm^-2), droplet size, and proximity of the spray droplet deposit to fungal spores was investigated with Mycosphaerella fijiensis ascospores on the banana (Musa AAA) leaf surface for two contact fungicides: chlorothalonil and mancozeb. When droplet size was maintained at a volume median diameter (VMD) of 250 μm while total spray volume per hectare changed, M. fijiensis ascospore germination on the leaf surface fell below 1% for both fungicides at a droplet deposit density of 30 droplet cm^-2. At a droplet deposit density of 50 droplet cm^-2, no ascospores germinated in either fungicide treatment. When both droplet size and droplet cm^-2 varied while spray volume was fixed at 20 litre ha^-1, ascospore germination reached 0% at 10 droplet cm^-2 (VMD=602 μm) for both fungicides. At lower droplet densities (2–5 droplet cm^-2 VMD=989 μm and 804 μm respectively), ascospore germination on the mancozeb-treated leaves was significantly lower than on the chlorothalonil-treated leaves. The zone of inhibition surrounding a fungicide droplet deposit (VMD=250 μm) on the leaf surface was estimated to extend 1·02 mm beyond the visible edge of the spray droplet deposit for chlorothalonil and 1·29 mm for mancozeb. The efficacy of fungicide spray droplet deposit densities which are lower than currently recommended for low-volume, aerial applications of protectant fungicides was confirmed in an analysis of leaf samples recovered after commercial applications in a banana plantation. Calibrating agricultural spray aircraft to deliver fungicide spray droplets with a mean droplet deposit density of 30 droplet cm^-2 and a VMD between 300 and 400 μm will probably reduce spray drift, increase deposition efficiency on crop foliage, and enhance disease control compared to aircraft calibrated to spray finer droplets. © 1997 SCI.     

Maturation of pseudothecia and discharge of ascospores of <Emphasis Type="Italic">Leptosphaeria maculans</Emphasis> on oilseed rape stubble

The effects of temperature, wetness and darkness on formation of pseudothecia and the effect of temperature on the release of ascospores of L. maculans on oilseed rape stubble were studied in a controlled environment in South Australia. Pseudothecia of L. maculans developed at 5–20°C and the time taken to reach maturity and discharge ascospores decreased from 58 days at 5°C to 22.2 days at 15°C. The optimum temperature of those tested for pseudothecium maturation was between 15°C and 20°C but fewer pseudothecia were observed at 20°C than at 15°C. Exposure to a 12 h photoperiod enhanced pseudothecium formation on the stubble compared with continuous darkness. No pseudothecia formed on stubble moistened once a day at 15°C, whereas three sprays of water per day decreased maturation time in comparison with two sprays per day. More ascospores were released for a longer duration at 20°C than at 5–15°C, although peak sporulation occurred earlier at 5–10°C than at 20°C. These findings highlight the importance of moisture, temperature and light for production and release of inoculum from stubble. This information, combined with field data, may help to predict the onset of inoculum release.     

河北省和山东省黄瓜霜霉病菌对氟吡菌胺的抗性及常规药剂对黄瓜霜霉病的田间防效

为明确黄瓜霜霉病菌Pseudoperonospora cubensis对氟吡菌胺的抗性时空动态,2011—2016年从河北省和山东省黄瓜主产区采集1 821株霜霉病菌,采用叶盘漂浮法检测供试菌株对氟吡菌胺的敏感性,并以茎叶喷雾法评估5种常规药剂对黄瓜霜霉病的田间防效。结果表明,河北省和山东省黄瓜主产区的黄瓜霜霉病菌对氟吡菌胺已普遍产生了低度抗性,平均抗性倍数为5.86;所有供试菌株的抗性频率为51.89%,其中低抗菌株及中抗菌株分别占36.18%和15.71%;平均抗性指数为0.34,每年检测的抗性频率、抗性倍数及抗性指数呈增长趋势,且随着监测区域的变化而变化。在河北省定兴县和山东省寿光市进行的田间防效试验结果显示,按推荐剂量喷施,687.5 g/L氟吡菌胺·霜霉威盐酸盐SC对黄瓜霜霉病防效显著高于常规对照药剂68%精甲霜灵·代森锰锌WG、58%甲霜灵·代森锰锌WP、80%代森锰锌WP及250 g/L嘧菌酯SC的防效,但防效明显下降,由2011年的92.58%～93.31%降至2016年的80.07%～80.82%。表明需要制定和实施抗药性治理对策,如限制山东和河北2省黄瓜的每个生长季节中687.5 g/L氟菌·霜霉威SC的使用不超过2次,而且要与不同作用机理的卵菌杀菌剂交替使用防治黄瓜霜霉病。     

多菌灵等5种杀菌剂对烟草立枯病菌的生物活性

采用生物测定方法分析了烟草立枯病菌Rhizoctonia solani在菌丝生长、菌核形成与萌发阶段对5种杀菌剂(多菌灵、代森锰锌、菌核净、异菌脲及苯醚甲环唑)的敏感性,同时通过离体叶片法考察了5种杀菌剂对烟草立枯病的保护和治疗作用。结果表明:供试5种药剂对立枯病菌菌丝生长、菌核形成与萌发均表现出了不同程度的抑制活性,同时对烟草立枯病具有一定的保护和治疗作用。其中,对菌丝生长以及菌核形成与萌发抑制活性最强的均是多菌灵,其抑制菌丝生长的EC50平均值为(0.06 ±0.01) mg/L,0.25和20 mg/L下对菌核形成和萌发的抑制率均为100%;其次为异菌脲[EC50值为(0.35 ±0.15) mg/L,2和100 mg/L下对菌核形成和萌发的抑制率分别为(54.79 ±12.58)%和100%]、苯醚甲环唑[EC50值为(0.55 ±0.53) mg/L,5和200 mg/L下对菌核形成和萌发的抑制率分别为(97.97 ±2.64)%和100%]及菌核净[EC50值为(1.31 ±0.14) mg/L,10和100 mg/L下对菌核形成和萌发的抑制率均为100%];最弱的均是代森锰锌,其抑制菌丝生长的EC50平均值为(6 ±0.20) mg/L,10和200 mg/L下对菌核形成和萌发的抑制率分别为(43.58 ±31.87)%和0。离体试验表明:对烟草立枯病保护作用最强的是多菌灵、异菌脲和菌核净,50 mg/L时防效均 > 99%,其次为代森锰锌(50 mg/L防效为75.83%),最弱的是苯醚甲环唑(50 mg/L防效为39.29%);治疗作用最强的也是多菌灵,50 mg/L防效为93.46%,其次为菌核净、异菌脲和苯醚甲环唑(200 mg/L时防效均 > 84%),最弱的为代森锰锌(800 mg/L时防效为76.40%)。研究结果可为烟草立枯病化学防治药剂筛选提供参考和依据。     

Fitness Cost Associated with Loss of the AvrLm4 Avirulence Function in Leptosphaeria maculans (Phoma Stem Canker of Oilseed Rape)

Near-isogenic isolates of Leptosphaeria maculans differing at the AvrLm4 avirulence locus (AvrLm4 or avrLm4) were produced in vitro. Methods for inoculation of leaves of oilseed rape with ascospores or conidia were compared. The ‘ascospore shower’ inoculation was the most efficient method for use when inoculum is limited (e.g. ascospores produced in vitro). It was used in controlled environments to compare fitness of AvrLm4 and avrLm4 isolates at 5, 10, 15, 20 or 25 °C on leaves of oilseed rape cultivars Eurol and Darmor lacking the resistance gene Rlm4, which corresponds to AvrLm4. At all temperatures tested, AvrLm4 ascospores produced more lesions than avrLm4 ascospores. The diameters of lesions produced by AvrLm4 ascospores were greater than those of lesions produced by avrLm4 ascospores. At 15–20 °C, more lesions initiated by AvrLm4 ascospores produced pycnidia than did lesions initiated by avrLm4 ascospores. However, there were no differences between AvrLm4 and avrLm4 isolates in incubation period (from inoculation to appearance of lesions) or rate of mycelial growth in leaves from lesions towards the stems. In field experiments with winter oilseed rape cultivars lacking Rlm4, the frequency of AvrLm4 isolates increased from 5.7% at the phoma leaf lesion stage (autumn) to 20.5% at the stem canker stage (summer) during 2002/2003 and from 7.9 to 11.5% during 2003/2004 growing seasons. Results of controlled environment and field experiments indicate that avrLm4 isolates have a fitness cost compared to AvrLm4 isolates.     

六种喷雾助剂提高硝磺草酮防除稗草及反枝苋效果的作用机理初探

以各助剂临界胶束浓度(CMC)为参考,在室内条件下研究了添加不同浓度6种喷雾助剂对硝磺草酮防除禾本科杂草稗草及阔叶杂草反枝苋效果的影响,并探讨了各助剂的CMC值与硝磺草酮药效之间的关系。从助剂改变药液在植物叶片上的接触角与最大稳定持流量两个方面,分析了6种助剂对提高硝磺草酮除草效果的原因。结果表明:6种供试助剂添加浓度在不小于其CM C值时即可明显提高硝磺草酮在杂草上的有效沉积量,且均可不同程度地提高硝磺草酮对稗草及反枝苋的除草活性,对稗草的鲜重抑制活性比对反枝苋的高;其中GY-Tmax和S903效果较好,其次是GY-T12和QS-304,OP-10与S625效果略差。6种助剂通过降低药液在两种杂草叶片上的接触角、增大药液对靶标植物的最大稳定持流量,可提高硝磺草酮的除草效果。     

Ascospores of the Japanese pear scab fungus (<Emphasis Type="Italic">Venturia nashicola</Emphasis> Tanaka &; Yamamoto) are discharged during the day

We investigated the diurnal pattern of ascospore discharge of the Japanese pear scab fungus (Venturia nashicola Tanaka & Yamamoto) in an orchard. Ascospores of V. nashicola were mainly discharged during the day. Most ascospores were discharged from 7:00 to 19:00: 99.6% in 2001, 99.3% in 2002, and 93.8% in 2005. Because the ascospores were discharged only when the fallen diseased leaves were wet from precipitation, the wetness of these leaves is probably imperative for spore discharge. Ascospore discharge began immediately after precipitation in the daytime. When it rained at night, however, ascospore discharge did not begin until the following morning and never began immediately after precipitation. We also investigated other meteorological factors. When fallen diseased leaves were wet, the percentage of ascospore discharge was positively correlated with the amount of solar radiation and atmospheric temperature and negatively correlated with relative humidity. Ascospore discharge was interrupted by a decrease in solar radiation and atmospheric temperature and by increased relative humidity at night. This report is the first that V. nashicola discharges ascospores primarily during the day.     

Effect of six sanitation treatments on leaf litter density, ascospore production of Venturia inaequalis and scab incidence in integrated and organic apple orchards

A two-year study was conducted to determine the effect of six sanitation treatments on leaf litter density (LLD), relative ascospore production of Venturia inaequalis and scab incidence on spur-leaf clusters, leaves and harvested fruits, on two cultivars with low and high scab susceptibilities, in Hungarian integrated and organic apple orchards. The following sanitation treatments were used: sprays of lime sulphur in autumn, collecting fallen leaves in autumn, straw mulch cover in late winter, sprays of lime sulphur followed by mulch cover, collecting fallen leaves followed by mulch cover, collecting fallen leaves followed by covering the orchard floor with plastic foil, and non-sanitized control. LLD decreased continuously in all treatment plots by 0–23% by mid-May in both orchards and years; however, LLD reduction was 1.4–4.2 times higher in the organic orchard compared to the integrated one. All treatments, except for the lime sulphur treatment, resulted in significant (P < 0.05) reduction of LLD and ascospore production in both the integrated and organic apple orchards compared to non-sanitized plots. The most efficient treatment was leaf collection combined with plastic foil cover, followed by leaf collection combined with mulch cover, leaf collection alone, mulch cover alone, and lime sulphur spray combined with mulch cover, with a reduction in the ascospore production of >95, 72–92, 56–79, 24–38, and 27–46%, respectively, in the mean of both orchards and years. However, only treatments of leaf collection applied alone, or in combination with mulch or with plastic foil cover reduced significantly (P < 0.05) leaf and/or fruit scab incidence by 18–57% compared to non-sanitized plots. These three leaf collection treatments are recommended in both integrated and organic orchards and the possibilities of successfully incorporating these methods into orchard management practices are interpreted.     

柑桔脂点黄斑病病原菌的研究

 根据对采自江、浙、黔、川、滇等省部分产桔区的病叶进行分离培养和接种的研究,证明上述各地都有柑桔脂点黄斑病发生。本病症状初呈黄斑,后转为脂斑,有时可进而转变成褐色小园星。病原菌为柑桔球腔菌(My-cosphaerella citri Whiteside),无性阶段为柑桔灰色疣丝孢(Stenella citri-grisea (Fisher) Sivanesan),其主要形态特征与J.O.Whiteside报道的美国佛罗里达州柑桔脂斑病病原菌基本相同,但接种后表现的病状有所差异。病菌的假囊壳产生在落地将朽的病叶上,子囊孢子起着初侵染作用;发生在落叶上的分生孢子数量很少,看来再侵染作用不大,但在培养基上可产生较多的无性孢子.接种表明,病菌从寄主的气孔侵入,潜育期1~2个月以上,其长短与柑桔品种有关,在江苏太湖桔区,此菌主要以菌丝体在病叶中越冬,翌年4-9月间落叶上产生子囊孢子传播侵染,春、夏、秋、梢的新叶均可受害,以春梢叶片被害最重.