西北荒漠绿洲区隔沟交替灌溉对棉花生长及产量与经济效益的影响

2006～2007连续两年在石羊河流域下游民勤县干旱荒漠绿洲区大田试验覆膜条件下隔沟交替灌溉(AFI)和常规沟灌(CFI)对棉花生长、产量及经济效益的影响.结果表明,隔沟交替灌溉方式对棉花株高的生长起到了抑制作用,且结铃率高干常规沟灌处理;在次灌水定额为当地畦灌水平的50%左右时隔沟交替灌溉与常规沟灌处理相比,能够提高棉花的产量和霜前花比例,增加经济效益.在荒漠绿洲区隔沟交替灌溉是一种有效的灌溉方式,可以实现节水优质高效的目标.     

不同灌水量对膜下滴灌冬马铃薯生长及水分利用效率的影响

通过田间试验,设置1350 m3·hm~(-2)、1650 m3·hm~(-2)、1950 m3·hm~(-2)、2250 m3·hm~(-2)4个灌水量和1个常规沟灌为对照,研究膜下滴灌对马铃薯的生长、产量和水分利用效率的影响。结果表明:膜下滴灌马铃薯生长发育快,株高、单株茎叶鲜重、单株结薯数、单株块茎鲜重高于常规沟灌,膜下滴灌较沟灌增产6 416.08 kg·hm~(-2),增产21.29%,水分利用率高79.5 kg·hm~(-2)·mm-1。膜下滴灌下不同灌水量马铃薯水分利用率随灌水量增加呈降低趋势,产量和耗水量随灌水量增加而增加,滴灌1950 m3·hm~(-2)的产量最高,为39 732.0 kg·hm~(-2),当灌水量增加到2250 m3·hm~(-2)时,产量较滴灌1950 m3·hm~(-2)处理的下降6 624.5 kg·hm~(-2),下降16.67%。从产量提高和节水方面考虑,在生育期间有效降雨量在70 mm左右时,灌水量在1650~1950 m3·hm~(-2)较为适宜。     

不同畦灌方式对冬小麦土壤水分和水分利用效率的影响

通过田间畦灌试验，研究了冬小麦主要生育阶段的需水规律，分析了不同畦灌方式对冬小麦土壤水分及水分利用效率的影响，评价不同畦灌处理下的灌水质量及节水效益。结果表明，冬小麦灌浆期对水分需求量最大；与漫灌(CK）处理相比，冬小麦畦灌小区30 m×3 m的灌水均匀度与灌溉效率最高，达到93.33%和84.46%，耗水量减少了5.96%，产量增加了25.30%，水分利用效率提高了33.24%，增收1561.61元·hm^-2。结合当地实际生产情况，推 广适宜的畦灌模式是入畦单宽流量5 L·m^-1·s^-1，畦宽3 m左右，畦长30 m左右为宜。     

宁夏引黄灌区春小麦畦灌试验研究

通过田间畦灌试验,分析春小麦不同生育阶段的需水量及水分盈亏量,评价不同畦灌处理下的灌水质量及节水增收效果。结果表明:畦灌小区50m×2m与漫灌(CK)相比较,水分利用效率提高了26.78%,产量增加了13.08%,具有一定的节水增效作用,结合各地实际生产情况合理推广利用能够取得良好的经济效益。     

不同沟灌模式对甜椒生长和产量的调控效应

试验研究了交替隔沟灌溉(AFI)、常规沟灌(CFI)、固定隔沟灌溉(FFI)3种灌溉模式下甜椒植株形态变化、水分利用效率、产量及其构成因素。结果表明:(1)采收期末CFI、AFI、FFI处理平均株高分别为69.3 cm、63.6 cm和52.2 cm,差异达显著水平(P0.05);前期AFI处理株高增长量小于CFI处理,后期增长量逐渐增加且大于CFI处理。(2)整个生育期AFI处理径粗基本最大,最大值为1.38 cm。(3)采收期AFI与CFI和FFI处理叶面积指数差异极其显著,FFI和CFI处理差异达显著水平。(4)全生育期AFI主根长最长,为6.36 cm,AFI主根粗和根冠比介于CFI和FFI之间。(5)分析产量水平水分利用效率,AFI处理比CFI和FFI高46%和52%,分析群体水平水分利用效率,AFI处理比CFI和FFI高41%和38%。(6)全生育期同一水分梯度下,AFI处理产量最高,为62386.1 kg·hm-2,比CFI和FFI处理产量增加4 447 kg·hm-2和20 973 kg·hm-2,各处理间产量差异达显著水平。     

分区交替灌溉对梨生长结果及水分利用效率的影响

为探讨半干旱地区农业节水的途径,以黄冠梨为试材,研究了分区交替灌溉对梨营养生长、结果和水分利用的影响.结果表明:采用1/2量分区交替灌溉较全量常规灌溉,光合速率稍有降低,但气孔导度和蒸腾速率显著降低,因此水分利用效率显著提高.在盆栽试验中灌水量为1/3量分区交替灌溉光合速率则受到显著影响,1/2量分区交替灌溉处理的枝梢和根系生长量显著大于1/3量分区交替灌溉,秋季复水后,以1/2量和1/3量分区交替灌溉处理新发生的侧根和须根较多.在田间试验不同灌溉处理中,1/2量分区交替灌溉对产量品质无显著影响,灌溉水和降雨总水分利用效率最高,较全量常规灌溉提高了22.9%.     

民勤绿洲膜下滴灌洋葱节水高产灌溉制度

通过TDR土壤水分测定仪结合PC-2S土壤墒情监测系统及作物生理生态指标常规测定方法测定了膜下滴灌洋葱不同灌水处理下土壤水热动态、生长动态、产量效应、水分利用效率、耗水规律及经济效益,并结合TRM-ZS3全自动气象站气象数据比较不同滴灌处理的优越性,分析了不同灌水处理对水热变化、产量、灌溉水利用、耗水特性及效益的影响。研究表明,膜下滴灌土壤水热变化均匀、利用率高,有利于洋葱生长;适宜的滴灌定额条件下(T4)洋葱单株重、横茎及纵茎均较大,产量较对照(CK)增加8.65%,节水21.6%,灌溉定额降低120 mm,生育期耗水降低136.9 mm,水分利用效率提高37.31%,水分生产力达27.0元·m~(-3),净收入增加13.8%。与对照覆膜畦灌相比,滴灌处理生育期耗水强度较对照均降低0.8 mm·d~(-1)以上,能有效降低棵间无效蒸发损失,减少生育期耗水,改善土壤水热状况,提高作物产量、水分利用效率和经济效益,是一种经济可行、易于推广的节水方法。     

底墒对压砂地西瓜生长和产量的影响

通过田间试验研究了底墒差异对西瓜生长和产量以及水分利用效率的影响。结果表明:播前适宜的底墒(0~100 cm土层储水量在223~238 mm)可以促进西瓜主蔓长的生长、叶片的发生以及提高西瓜叶面积;播前底墒较丰时(0~100 cm土层储水量在283 mm),不利于西瓜前期的生长。与播前不灌水相比,播前灌水造墒处理不同程度地提高了地上部生物量和西瓜产量;其中播前灌水量达到70m3/667m2时,西瓜产量和瓜蔓重最大,分别为1 645 kg/667m2和25.4 kg/667m2,相比播前不灌水处理分别提高了30%和49%。西瓜水分利用效率随播前土壤储水量增加而降低。     

不同灌溉方式下制种玉米叶面积指数、干物质累积与产量研究

通过田间试验,研究了畦灌、常规沟灌、隔沟交替灌3种灌溉方式对制种玉米叶面积指数(LAI)、干物质累积及产量的影响。结果表明:不同灌溉方式下制种玉米苗期LAI与产量呈显著正相关关系,抽穗后期LAI与产量呈显著负相关关系,表明在生殖生长后期,应适当采取控水、控肥措施降低植株的生长冗余。隔沟交替灌方式使作物根区土壤保持湿润和干燥区域交替出现,能诱导作物的补偿生长效应。隔沟交替灌(AFI)方式下制种玉米进入干物质快速累积期的时间早于传统沟灌(CFI)与小畦灌(SBI)。制种玉米抽穗期干物质累积量与产量呈显著正相关关系(R~2=0.77)。隔沟交替灌溉方式下,制种玉米全生育期灌水8次,灌溉定额为2 250 m~3·hm~(-2)的灌溉制度能稳定提高经济产量,具有较好的灌水效果,但在抽穗期~灌浆期应考虑适当增加灌水频率或灌水定额。     

不同灌溉模式下氮肥水平对水稻生物学特性及水分利用效率的影响

为了研究不同灌溉模式下氮肥水平对水稻生物学特性及水分利用效率的影响,以两优培九为材料,设计3种不同的灌溉模式（常规灌溉、干湿交替灌溉和厢沟灌溉,分别记作W1,W2,W3）和4种不同氮肥水平（0,90,180,270 kg/hm2,分别记作F0,F1,F2,F3）的大田试验。结果表明：与W1处理相比,W2和W3处理水稻灌...     

Richtlinien der Verbände des ökologischen Landbaus zum Vorratsschutz

Zusammenfassung Verbände des ökologischen Landbaus wie z. B. Bioland, Gäa, Demeter; Naturland, Ernte für das Leben oder Bio Suisse beschränken ihre Mitglieder bei der Wahl von Vorratsschutzmaßnahmen. Vorrang besitzen Maßnahmen zur Vermeidung von Schädlingen gegenüber Bekämpfungsmaßnahmen. Fallen müssen zur Befallsüberwachung eingesetzt werden, um einen Befall durch Vorratsschädlinge frühzeitig zu erkennen. Diese Maßnahmen sollen den weitgehenden Verzicht auf chemisch-synthetische Mittel ermöglichen. In diesem Beitrag werden die Empfehlungen der Verbände mit den derzeit verfügbaren chemischen Mitteln für den Vorratsschutz abgeglichen. Erfahrung in der praktischen Umsetzung von physikalischen und biologischen Verfahren werden diskutiert und Defizite bei der Befallsüberwachung und Bekämpfung beschrieben.     

Development of protocols for detection of Colletotrichum acutatum and monitoring of strawberry anthracnose using real-time PCR

Real-time PCR (TaqMan®) assays were developed for the specific detection and discrimination of Colletotrichum spp., C. acutatum and C. gloeosporioides causing anthracnose in strawberry using the most divergent area of the internal transcribed spacers (ITS1 and ITS2) and 5·8S ribosomal RNA (rRNA) gene region. The specificity of the new assays was tested using DNA from six species of Colletotrichum and nine fungal species commonly found associated with strawberry material, and additionally by comparing the sequences with those from databases using a blast search. The sequences only showed identity with homologous sequences from the desired target organisms. The new assays were 10–100 times more sensitive than conventional PCR methods previously published for the diagnosis of strawberry anthracnose. When real-time PCR was compared with ELISA methods, PCR improved the sensitivity of the identification by obtaining positive results for samples of strawberry plant material that tested negative with ELISA. The development of C. acutatum was monitored using artificially infected strawberry crowns from two strawberry cultivars (Camarosa and Ventana) and a real-time PCR assay specific for this species between January and June 2006. The amount of C. acutatum detected using real-time PCR varied significantly by month ( P  < 0·001), but not by cultivar ( P  = 0·394). The new assays were shown to be useful tools for rapid detection and identification of these pathogens and to allow rapid and accurate assessment of the casual agents of anthracnose in strawberry.     

A systematic review of the literature reveals trends and gaps in integrated pest management studies conducted in the United States

Integrated pest management (IPM) is a broad‐based approach for addressing pests that negatively affect human and environmental health and economic profitability. Weeds, insects and disease‐causing pathogens (diseases) are the pests most often associated with IPM. A systematic review, widely used in other scientific disciplines, was employed to determine the most commonly studied IPM topics and summarize the reasons for these trends and the gaps. In a field synopsis of the literature, 1679 relevant published papers were identified and categorized into one of the following five broad areas: IPM and organic (organic), climate change and pests (climate), rural and urban IPM (rural and urban), next‐generation education (education) and advanced production systems (technology). Papers were examined in greater detail for at least one of the three main pests in a systematic review. A majority (85%) of IPM papers have been in the area of rural and urban IPM, primarily addressing agriculture (78%). Professionals, landowners and the general public were the focus of a majority (95%) of IPM papers on education. Technology is an increasing area of focus in the literature. Over the past 40 years, IPM papers have primarily (75%) addressed insects and been limited mostly to rural and urban settings. Climate change, technology and education specific to pest management studies are increasingly being published and will help broaden the focus that could result in increased adoption and development of IPM. © 2017 Society of Chemical Industry     

Thermal and hormonal regulation of the dormancy–germination transition in Amaranthus tuberculatus seeds

The transition from seed dormancy to germination is a multi‐step process. However, distinguishing between physiological processes involved in seed dormancy alleviation and those involved in germination has been difficult. We studied the seed dormancy alleviation process in Amaranthus tuberculatus, an important weed species in midwestern USA. Using three A. tuberculatus biotypes that differ in dormancy level, it was determined that stratification reduced seed dormancy from a high to a low level. Temperature alternation alleviated low seed dormancy and triggered germination. Exogenously applied abscisic acid (ABA) and gibberellic acid (GA) had no effect on seeds with high dormancy. However, ABA and paclobutrazol (a GA biosynthesis inhibitor) significantly reduced germination of seeds with low dormancy. Hormones could not replace the effects of stratification or temperature alternation on dormancy alleviation. Based on our results, we propose a seed dormancy–germination transition model in which the dormancy of A. tuberculatus seeds is progressively reduced from a high to a low level; but environmental conditions (i.e. stratification) can accelerate the dormancy alleviation process. Under low dormancy levels, the seed is more sensitive to environmental cues that are responsible for removing dormancy and triggering germination (i.e. temperature alternation). Finally, ABA and GA regulation occurs primarily during the final transition from low dormancy to germination rather than the alleviation of high dormancy.     

Description ofPauesia (Pauesia)anatolica (Hymenoptera: Braconidae, Aphidiinae) sp. nov., a parasitoid of the cedar aphidCinara cedri

The first parasitoid species reared from a population of the cedar aphid,Cinara cedri Mimeur, 1935 (Hemiptera: Aphididae), from the peninsula of Anatolia in Turkey is described.Pauesia anatolica (Hymenoptera: Braconidae, Aphidiinae) is closely related to some species of thelaricis group ofPauesia from which it differs in the number of antenomers, the propodeum and features of the female genitalia. Its potential use as a natural enemy in areas where the aphid has been introduced is discussed. http://www.phytoparasitica.org posting Aug. 28, 2005.     

Current statistical issues in Weed Research

The correct design of experimental studies, the selection of the appropriate statistical analysis of data and the efficient presentation of results are key to the good conduct and communication of science. The last Guidance for the use and presentation of statistics in Weed Research was published in 1988. Since then, there have been developments in both the scope of research covered by the journal and in the statistical techniques available. This paper addresses the changes in statistics and provides a reference work that will aid researchers in the design and analysis of their work. It will also provide guidance for editors and reviewers. The paper is organised into sections, which will aid the selection of relevant paragraphs, as we recognise that particular approaches require particular statistical analysis. It also uses examples, questions and checklists, so that non-specialists can work towards the correct approach. Statistics can be complex, so knowing when to seek specialist advice is important. The structure and layout of this contribution should help weed scientists, but it cannot provide a comprehensive guide to every technique. Therefore, we provide references to further reading. We would like to reinforce the idea that statistical methods are not a set of recipes whose mindless application is required by convention; each experiment or study may involve subtleties that these guidelines cannot cover. Nevertheless, we anticipate that this paper will help weed scientists in their initial designs for research, in the analysis of data and in the presentation of results for publication.     

Electrophoretic and serological comparisons of pathogenesis-related (b) proteins from different plant species

Preparations of pathogenesis-related (b) proteins (PRs) from differentNicotiana species, tomato,Gynura aurantiaca, bean, and cowpea were compared to each other and to bean chitinase and a constitutive apple agglutinin by electrophoresis in polyacrylamide gels both in the absence and in the presence of SDS, and by serological double diffusion analysis using antisera against tobacco PRs and bean chitinase. PRs from different plant genera displayed a similar but not identical range of relative mobilities in both native and SDS gels, whereas bean chitinase and apple agglutinin were clearly different. None of the antisera reacted with any of the PR preparations from plant genera other than the one from which the antigen(s) had been derived. Whilst PRs within the genusNicotiana are serologically related and can be identical, PRs from different plant genera seem to be sufficiently different to be considered as genus-specific.     

Contribution of Biological Control to Integrated Pest Management of Tephritid Fruit Flies in the Tropics and Subtropics

The biological control of pest tephritid flies using parasitoids has been successful in relatively few subtropical and tropical regions. The best documented successes were in Hawaii and Florida, USA, Fiji and southern Europe. There were relatively limited successes in Australia, Costa Rica and Mexico. With the accidental establishment of new pest tephritids, such as Bactrocera latifrons (Hendel) in Hawaii or Bactrocera papayae Drew and Hancock in Australia, foreign exploration for new parasitoids is essential. A renewal of interest in classical biological control has recently occurred, although not at the same level as in the 1940s and 1950s. New parasitoid species are currently being obtained for several tephritids, such as Ceratitis capitata (Weidemann), B. latifrons and Anastrepha suspensa (Loew). The advances in mass rearing and quality control technology for parasitoids has enabled researchers to perform large-scale field testing of these parasitoids to determine the potential of augmentative releases. Numerous studies on the augmentative release of parasitoids have been done. Historically, the larval—pupal parasitoid Diachasmimorpha longicaudata (Ashmead) has been the most frequently studied parasitoid, due to the ease of rearing this species. However, recent successes in rearing other species with different biologies, e.g. the egg—pupal parasitoid Biosteres arisanus (Sonan), the gregarious eulophid, Tetrastichus giffardianus (Silvestri) and the pupal parasitoid, Coptera sp., will enable researchers to broaden the repertoire of parasitoid species for the future. Both successes and failures in augmentative releases have occurred. Without knowledge of the behavioural ecology of parasitoids, the reasons for success or failure can only be surmised. Recent research on the dispersal and host habitat finding of tephritid parasitoids will provide insights into improving augmentation and conservation strategies. The integrated pest management (IPM) of tephritid flies in the tropics has been less well-developed than research and programmes for tephritids in temperate zones. Significant emphasis is now being placed on the development of quarantine treatment methods that are environmentally sound; thus IPM will take a larger role. Several existing pest management strategies are reviewed which show the potential for compatibility with the activities of tephritid parasitoids. These include trap cropping, insecticides with selective toxicity to the target pests, mass trapping with parapheromones, the sterile insect technique and field sanitation.     

Rapid Identification of Clavibacter michiganensis Subspecies sepedonicus Using Two Primers Random Amplified Polymorphic DNA (TP-RAPD) Fingerprints

Twenty strains of Clavibacter michiganensis subsp. sepedonicus from different geographic origins and other reference strains of the same and different species, including other potato pathogens, were analysed with a new procedure named TP-RAPD that originates fingerprints of bacterial species. This procedure uses two primers to amplify the 16S rDNA gene. At 45 °C of annealing, the PCR product electrophoresed in agarose gels produced a band pattern that was different in all bacterial species studied as well as in the subspecies of C. michiganensis. All strains of C. michiganensis subsp. sepedonicus displayed the same TP-RAPD number of pattern. Unlike Gram negative bacteria, Gram positives of high G + C content, such as Clavibacter, produced low bands in TP-RAPD. By using a different set of two primers also based in the 16S rDNA sequence from Escherichia coli a more adequate amplification of Gram positives of high G + C including a greater number of bands was obtained. TP-RAPD patterns using the new set of primers described in this work is a reliable and fast method to identify C. michiganensis subsp. sepedonicus.