几种药剂对水稻纹枯病的防治效果探究

使用250g/L嘧菌酯SC 30g/667m~2、240g/L噻呋酰胺SC 30ml/667m~2、5%己唑醇SC 80ml/667m~2、5%井冈霉素SP 100g/667m~2防治水稻纹枯病,于水稻纹枯病发病初期施第1次药,以后每隔7d施1次,共施3次,3次施药后10d各药剂的防治效果均达67.9%~88.9%。其中,嘧菌酯、噻呋酰胺和己唑醇这3种药剂的防效好且相当,为88.0%~88.9%,井冈霉素处理的防效差显著低于以上3种药剂处理的防效,为67.9%。     

防治水稻纹枯病药剂田间筛选试验

为筛选生产上防治水稻纹枯病的高效、安全药剂,于2014年8月在田间进行了防治纹枯病10种药利筛选试验。结果表明,嘧菌酯类和噻呋酰胺类复配剂防效突出。24%密菌酯·己唑醇悬浮剂20 mL/667m~2、24%噻呋·咪鲜胺悬浮剂30 mL/667m~2处理对水稻纹枯病的株防效超过或接近85%,病指防效均达90%以上,值得进一步示范推广。     

噻呋酰胺24％悬浮剂防治水稻纹枯病试验

试验表明,噻呋酰胺24％悬浮剂对水稻纹枯病有良好防效,且持效期长,可有效控制水稻纹枯病危害,药后15-30d,噻呋酰胺24％悬浮剂20mL／667m^2处理的防效为70．92％-83．96％,优于井冈霉素等药剂。     

三种药剂防治水稻纹枯病试验研究

为筛选防治水稻纹枯病的有效药剂,2012年春季进行了1%申嗪霉素悬浮剂、24%噻呋酰胺悬浮剂和75%苯醚甲环唑.咪鲜胺锰盐可湿性粉剂三种药剂防治水稻纹枯病的田间药效试验。结果表明:1%申嗪霉素悬浮剂、24%噻呋酰胺悬浮剂和75%苯醚甲环唑.咪鲜胺锰盐可湿性粉剂三种药剂防效分别为96.36%、94.72%和91.68%,对照药剂16%井冈霉素可湿性粉剂、30%苯醚甲环唑.丙环唑乳油的防效分别为88.83%和83.96%,试验药剂具有较好的防治效果。     

12种杀菌剂防治水稻纹枯病田间试验研究

本文报道了12种杀菌剂防治水稻纹枯病的田间试验研究。结果表明:噻呋酰胺24%悬浮剂339g/hm2、嘧菌酯25%悬浮剂500g/hm2、丙环唑25%乳油750g/hm2在2次药后15d对水稻纹枯病的防治效果分别为91.5%、88.1%、86.6%,显著高于其他处理;肟菌·戊唑醇75%水分散粒剂防效为77.0%,稍次于丙环唑25%乳油;其他8种杀菌剂的防效在54.1%~68.7%之间,防效不太理想;井冈霉素20%可湿性粉剂的防效仅为56.6%,故笔者认为在水稻纹枯病大发生年份,尽量选用其他高效的杀菌剂进行预防和防治。     

30％苯甲·丙环唑乳油防治水稻纹枯病效果

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试验对比,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20％井冈霉素平均防效79.52％提高4.62个百分点;减量控害区667m产量527.9kg,比常规用药20％井冈霉素对照区增产31.2kg,增幅6.28％.每667m减少施药用工2.5元,667m2增加效益62.9元.建议使用时,每667m2用30％苯甲·丙环唑30ml兑水45 kg于纹枯病发生盛期对水稻叶面均匀喷雾.     

6种农药对水稻纹枯病和稻曲病的防治效果

为评价6种常规农药对水稻纹枯病和稻曲病的防治效果,特开展田间实验,结果表明,在纹枯病重发情况下24%井冈霉素AAS、28%井冈霉素ASP、240 g/L噻呋酰胺SC、10%己唑醇SC和30%苯甲?丙环唑EC对纹枯病均具有很好的防效,41%甲硫?戊唑醇SC的防效略差。在稻曲病中等发生情况下24%井冈霉素AAS、28%井冈霉素ASP对稻曲病防效好,30%苯甲?丙环唑EC、41%甲硫?戊唑醇SC对稻曲病具有较好的兼治作用,而240 g/L噻呋酰胺SC对稻曲病防效差。     

水稻纹枯病防治药剂筛选试验研究

为筛选防治水稻纹枯病的理想长效药剂,本站选择了10种药剂进行了田间药效试验,各期调查,均以每667m2用嘧菌酯·噻呋酰胺20%水分散粒剂70g、嘧菌酯·戊唑醇75%水分散粒剂10g、噻呋酰胺·已唑醇27.8%悬浮剂20m L、噻呋酰胺24%悬浮剂20m L、肟菌·戊唑醇75%水分散粒剂15g、嘧菌脂25%悬浮剂30m L等6种药剂处理对水稻纹枯病具有很好的防控效果,用药1次,可有效控制20d以上,对水稻生长安全,是防治水稻纹枯病的理想长效药剂。     

苯甲·嘧菌酯不同药量对早稻纹枯病控制作用初探

试验结果表明,早稻每667m2用苯甲.嘧菌酯32.5%悬浮剂20、30、40mL施药2次,在第1次施药后11d对病情指数防效分别为55.4%、66.7%、67.4%,略优于噻呋酰胺处理,但差于井冈霉素处理,控病的速效性一般;第2次施药后12d对病情指数防效分别为79.0%、97.2%、97.8%,经最小显著极差法(LSR-SSR)比较,苯甲.嘧菌酯与噻呋酰胺的病情指数防效无显著差异,但与井冈霉素处理区有显著差异;控制纹枯病具有良好的持效性,并对早稻安全,且有促进青杆黄熟的作用。     

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）。     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.     

Brief Guide for Authors

正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad     

The parasitoid complex ofLiriomyza cicerina on chickpea (Cicer arietinum)

Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.     

Plant–herbivore asynchrony necessitates augmentative releases of the exotic beetle,Zygogramma bicolorata,to enhance the biological control of P arthenium hysterophorus

Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F ₃, F ₄ and F ₅, but not in F ₁ and F ₂ that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F ₁ and F ₂ in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.     

Effects of the saprophytic leaf mycoflora on growth and productivity of winter wheat

The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.     

Relationship Between Production of the Phytotoxin Prehelminthosporol and Virulence in Isolates of the Plant Pathogenic Fungus Bipolaris sorokiniana

A gas chromatographic method was developed to quantify the phytotoxin prehelminthosporol, which is a sesquiterpene metabolite of the plant pathogen Bipolaris sorokiniana. The toxin was extracted from mycelium or culture filtrates, pre-cleaned using solid phase extraction, and analyzed by gas chromatography as a trimethylsilyl-derivative. The detection limit of the method was 5ngl^–1 (signal to noise ratio 4:1) which corresponds to ca. 15ng prehelminthosporol per mg dry weight of mycelium or 15ng prehelminthosporol per ml culture filtrate. The total amount of prehelminthosporol (mycelium plus culture filtrate) increased with cultivation time when examined in six isolates of B. sorokiniana after 6, 9, 12 and 15 days of incubation. The screening experiment of 17 isolates for prehelminthosporol production after 8 days of incubation revealed significant differences in the toxin production between the isolates. The isolates with low toxin production had lower virulence towards barley roots compared to those with higher production of the toxin. However, the virulence did not increase with prehelminthosporol level among the high producing isolates. Prehelminthosporol was also analyzed in a number of related Bipolaris and Drechslera species. In addition to B. sorokiniana, three out of six Bipolaris species (B. setariae, B. zeicola, B. victoriae) produced prehelminthosporol, which indicates that ability to produce prehelminthosporol is conserved among closely-related Bipolaris species.     

Effect of botanical insecticides and bacterial toxins on the gut enzyme of the rice leaffolderCnaphalocrocis medinalis

The effect of botanical insecticides and bacterial toxins on gut enzyme activity of larvae of the rice leaffolderCnaphalocrocis medinalis (Guenée) (Insecta: Lepidoptera: Pyralidae) was investigated. Gut enzyme activities were affected by botanical insecticides and bacterial toxin individually and in combination. When fed a diet of rice leaves treated with botanical insecticides and bacterial toxins, in bioassays the activities of gut tissue enzymes — acid phosphatases (ACP), alkaline phosphatases (ALP) and adenosine triphosphatases (ATPase) — of rice leaffolder larvae were affected. When combined, the effect was more severe at a low concentration. Larvae that were chronically exposed to botanical insecticides and bacterial toxins showed a reduction in weight (59–89%) and exhibited a significant reduction in ACP, ALP and ATPase activities. The combination ofBacillus thuringiensis kurstaki and botanical insecticides caused a decrease of twofold in enzyme activity even at reduced concentration. A synergistic effect was found when botanical insecticides and bacterial toxins were combined at low doses. These effects were most pronounced in early instars. Clear dose-response relationships were established with respect to enzyme activity. In conclusion: (i) biopesticides are relatively safe and biodegradable; (ii) a synergistic effect of botanical insecticides and bacterial toxins was found; (iii) less expensive, readily available and naturally occurring biopesticides could be an alternative for organic and inorganic pesticides in controlling RLF. http://www.phytoparasitica.org posting Sept. 28, 2004.