“张持”式顺向残膜捡拾机构的设计与试验

针对现有残膜捡拾机构工作过程中土和杂物聚集在机组前进的方向造成的拥堵问题,为减小工作阻力,利用捡拾齿与土壤间阻力和弹簧拉力,设计了“张持”式顺向残膜捡拾机构,其包含摇臂装置和捡拾装置等装置仅在拖拉机拖拽下完成残膜捡拾,适应拖拉机前进速度。对捡拾齿进行受力分析和运动学分析,确定捡拾齿的直径为15 mm、周向排列数量14、轴向间距140 mm;通过分析捡拾齿闭合过程确定了轨道形状。田间试验表明,在机具作业速度5.15 km·h^-1、入土深度8.49 cm、张持距离7.61 cm时拾膜率达86.40%。     

抛膜钉齿式残膜弧形起膜捡拾装置设计与田间模拟试验

现有残膜回收机起膜装置难以彻底刨出土壤耕层内残留的多年废弃地膜,致使地膜继续沉积,严重破坏土壤再生能力。针对现有起膜装置碎片回收率低、漏收率较高的问题,设计了一种弧形起膜捡拾装置配合抛膜弹齿式残膜回收机使用,该装置主要由输膜辊、喂入辊、U形喂入齿、起膜杆齿、弧形钉齿等组成。在阐述整体结构、具体工作原理及主要部件设计特点的基础上,通过理论计算确定主要工作部件的结构参数。对弧形起膜捡拾装置主要部件进行受力分析和运动机理分析,并建立了运动学模型,分析得出弧形钉齿运动轨迹为余摆线,根据总体机构的运动学模型和钉齿尖运动模型的对比计算,得出残膜不漏扎、不漏挑的条件。利用Comsol软件对主要工作部件进行多体动力学和多物理场田间模拟试验,追踪粒子轨迹,以平均颗粒流速、平均横向颗粒速度、质量流率及旋转轴总力矩为试验因变量进行正交仿真试验,试验结果表明最优参数组合为工作速度1.2 m·s~(-1)、入土深度35 mm、挑膜转速55 r·min~(-1)。该工作参数下试验结果分别为平均颗粒流速0.9738 m·s~(-1),平均横向颗粒速度0.0278 m·s~(-1),质量流率0.0091 kg·s~(-1),钉齿总力矩38.9576 N·m。     

秸秆还田残膜回收一体机设计与试验

为提高新疆棉田残膜回收机械化水平,解决机具残膜回收率低、含杂率高等问题,研究设计一种秸秆还田残膜回收一体机。根据新疆棉花的种植模式和田间作业要求对整机的关键零部件进行设计,确定了甩刀型粉碎刀、绞龙转速为1 500 r·min^-1、捡膜滚筒回转半径为245 mm、脱模板回转半径为278.5 mm等零部件参数。选取机具行进速度、捡膜齿入土深度、输出轴转速为影响因素,以残膜回收率、含杂率为试验指标,设计三因素三水平正交试验并进行测试,确定了最优参数组合：机具前进速度7 km·h^-1、捡膜齿入土深度25 mm,输出轴转速760 r·min^-1。根据最优参数进行试验验证,结果表明：在最优参数组合下,残膜回收率的均值为85.03%,含杂率的均值为15.88%,其与理论值对比误差均小于3%,模型可靠。该研究成果可以满足残膜回收机田间作业要求。     

平作区棉秆粉碎与残膜回收联合作业机设计与试验

针对新疆平作区残膜回收作业过程中秸秆粉碎合格率低、残膜回收率低的问题,设计了一种秸秆粉碎与残膜回收联合作业机。对甩刀秸秆粉碎过程进行受力分析,确定了刀轴最佳转速为2 000 r·min-1。对起膜铲起膜机理和残膜捡拾过程进行分析,确定了导曲面参数方程和残膜捡拾装置主要工作参数。以机具作业速度v、起膜铲入土倾角α和残膜输送链转速n为影响因素,以秸秆粉碎合格率Y1和残膜回收率Y2为评价指标进行田间试验。结果表明:当起膜铲入土角为30°,机具前进速度为5.5 km·h-1,残膜输送链转速为120 r·min-1时,秸秆粉碎合格率为91.5%,残膜回收率为85.7%,整机运行状态良好,满足秸秆粉碎还田与残膜回收的技术要求。     

新型残膜捡拾机构的研究与试验

现有残膜捡拾机构只能用于我国北方地区地形平坦、土质疏松、含异物杂质少的表层或浅层的农田残膜回收。针对南方地形、土质和残膜主要集中在0～30 cm耕作层的情况,研发出新型残膜捡拾机构,能同时捡拾地表和地下的各种残膜。通过田间测试表明:该机重约600 kg,整机尺寸约为2.5 m×2.0 m×1.7 m,牵引动力采用36.75k W以上拖拉机,作业幅宽1.1 m,工作深度0～40 cm,碎膜捡拾率≥80%,整膜捡拾率≥90%,作业效率约420 m2·h-1,现已推广使用面积约141 hm2。     

一种新型残膜捡拾机的设计与试验

针对现有偏心伸缩杆式或气吸/气吹式残膜回收机存在的作业效率低、易堵塞、回收率差、适应性差等问题,设计了一种新型残膜捡拾机。该残膜捡拾机主要由起膜栅叉组件、锥形挑卷膜组件、压膜组件、搂耙式搂膜齿、机架以及减速器等部件组成。田间试验结果表明:新残膜捡拾机可一次性完成起膜、挑膜、卷膜、压膜、集膜作业工序;在土壤含水率为17.75%时,残膜捡拾率达到97.32%。     

全膜双垄沟地膜捡拾机的设计

为了解决地膜污染问题,通过对国内外地膜捡拾机的研究和借鉴,研制出全膜双垄沟地膜捡拾机。运用SolidWorks motion功能仿真弹齿M点的运动轨迹和X方向线性速度,得出收膜滚筒的转速为80 r·min~(-1),通过设计计算和考虑其它因素得出入土角为25°;在此基础上增加反向推膜机构,对集膜滚筒机械进行改进优化并做出样机。实验表明,该样机作业生产率为0.4~0.6 hm~2·h~(-1),地膜捡拾率为90%,使用可靠性为98%,工作效率高,制造成本低,适应性强。     

垂直双排链式残膜回收机输膜卸膜装置设计与试验

针对目前残膜回收机具存在的拾净率低和含杂率高等问题,设计了一种垂直双排链式残膜回收机。阐述了整体结构和工作原理,对输送装置的关键结构及参数进行分析,开展了垂直双排链作业过程中输膜和卸膜过程的运动学和动力学研究,通过理论计算确定了主要工作部件的作业参数,获得了影响残膜回收性能的关键因素;以输送链转速、卸膜链转速和输送链转运角为试验因素,以残膜拾净率及含杂率为试验指标进行响应面试验。结果表明：影响残膜回收性能的最佳工作参数为输送链转速86.08 r·min^-1、卸膜链转速128.97 r·min^-1、输送链转运角91.92°,最优参数组合下残膜拾净率为86.3%,含杂率为36.57%。在最优参数组合下进行田间验证试验,得到最优参数组合下的残膜拾净率为86.7%,含杂率为35.9%,满足行业要求。     

单垄双行马铃薯施肥覆膜播种机工作参数优化

为获得单垄双行马铃薯施肥覆膜播种机的最佳工作参数,通过改变单垄双行马铃薯施肥覆膜播种机播种作业性能指标的4个主要参数:机具前进速度、旋耕刀组刀头线速度、搅龙轴转速和覆土圆盘倾角,以播种合格率、膜上覆土厚度为评价指标进行马铃薯播种试验。结合正交试验,应用综合评分法得出了该机具作业时各参数的最优组合:机具前进速度为0.65 m·s~(-1)、旋耕刀组刀头线速度为0.90 m·s~(-1)、搅龙轴转速为950 r·min-1、覆土圆盘倾角为35°。根据该最优组合作业参数进行试验验证,试验结果表明,在此优化试验条件下,作业机播种合格率均值可达92.6%,膜上覆土厚度均值为40.1 mm,符合马铃薯种植机质量评价技术规范要求。     

一种小型马铃薯捡拾机的研制与试验

目前国内应用较为普遍的马铃薯挖掘机将薯块挖掘条铺后需人工捡拾,工作效率低、劳动强度大。针对以上问题,设计了一种与30 k W拖拉机配套的小型马铃薯捡拾机。该机主要由捡拾装置、薯土分离装置、薯块升运装置、薯块收集装置等几部分组成,制作了样机并进行了田间试验。试验表明:该机薯土分离彻底,机组纯工作小时生产率为0.35~0.38 hm~2·h~(-1),平均伤薯率为4.4%,漏薯率为2.1%,含杂率为6.3%。     

Dermestid beetles in ‘evolution Canyon’, lower Nahal Oren, Mt. Carmel, including new records for Israel

Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr _s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr _s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.     

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.     

Diagnostics,genetic diversity and pathogenic variation of ascochyta blight of cool season food and feed legumes

Molecular diagnostic techniques have been developed to differentiate the Ascochyta pathogens that infect cool season food and feed legumes, as well as to improve the sensitivity of detecting latent infection in plant tissues. A seed sampling technique was developed to detect a 1% level of infection by Ascochyta rabiei in commercial chickpea seed. The Ascochyta pathogens were shown to be genetically diverse in countries where the pathogen and host have coexisted for a long time. However, where the pathogen was recently introduced, such as A. rabiei to Australia, the level of diversity remained relatively low, even as the pathogen spread to all chickpea-growing areas. Pathogenic variability of A. rabiei and Ascochyta pinodes pathogens in chickpea and field pea respectively, appears to be quantitative, where measures of disease severity were based on aggressiveness (quantitative level of infection) rather than on true qualitative virulence. In contrast, qualitative differences in pathogenicity in lentil and faba bean genotypes indicated the existence of pathotypes of Ascochyta lentis and Ascochyta fabae. Therefore, reports of pathotype discrimination based on quantitative differences in pathogenicity in a set of specific genotypes is questionable for several of the ascochyta-legume pathosystems such as A. rabiei and A. pinodes. This is not surprising since host resistance to these pathogens has been reported to be mainly quantitative, making it difficult for the pathogen to overcome specific resistance genes and form pathotypes. For robust pathogenicity assessment, there needs to be consistency in selection of differential host genotypes, screening conditions and disease evaluation techniques for each of the Ascochyta sp. in legume-growing countries throughout the world. Nevertheless, knowledge of pathotype diversity and aggressiveness within populations is important in the selection of resistant genotypes.     

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     

Epidemiology of Toxigenic Fungi and their Associated Mycotoxins for Some Mediterranean Crops

Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.     

A survey of the genera of<Emphasis Type="Italic">Microgaster</Emphasis> latreille and<Emphasis Type="Italic">Hygroplitis</Emphasis> thomson (Hymenoptera: Braconidae: Microgastrinae) from China

The genera ofMicrogaster Latreille 1804 andHygroplitis Thomson 1895 from China are presented systematically in this paper. Thirty-two species ofMicrogaster and three species ofHygroplitis are known in China. Diagnosis, character variation, distribution and host of each species among the two genera are presented, including its host and distribution. Keys to the species ofMicrogaster andHygroplitis are given. http://www.phytoparasitica.org posting Dec. 19, 2006.     

Plant Viruses Transmitted by Whiteflies

One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.     

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.     

The use of Solacol® (validamycin) as a growth retardant in the isolation of soil fungi

Solacol^®, a formulation of the antibiotic validamycin, at 0.33% in 2% malt extract agar, reduced the spread of fungi on dilution plates drastically and allowed twice as much incubation time before subculturing; this resulted in an elevated number of species isolated. Using pure cultures of 62 common soil fungi, it was shown that all fast-growing species (exceptPythium ultimum) were efficiently inhibited but not completely suppressed. Inhibition was comparable to that by 0.5% oxgall, though, while this substance completely suppressed several species, Solacol very strongly inhibited onlyGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum andRhizoctonia solani. In a further experiment each separate constituent of Solacol was tested against 22 fungi at equivalent concentrations. Validamycin strongly inhibitedChaetomium globosum and two Basidiomycetes, though hardly more than the non-ionic detergent which mainly inhibited the other fungi. A few species were, however, more inhibited by Solacol than by the detergent alone. Solacol at 0.33% is a suitable aid in dilution plating of soil fungi, by increasing the number of colonies and species observed.Samenvatting Solacol^®, een formulering van het antibioticum validamycine, remde de groei van schimmels in verdunningsplaten met een concentratie van 0.33% in 2% moutagar en maakte het mogelijk de periode tot afenten met een factor 2 te verlengen; daardoor was het aantal geïsoleerde soorten duidelijk toegenomen. Met reincultures van 62 algemene grondschimmelsoorten werd aangetoond, dat alle snelgroeiende soorten (met uitzondering vanPythium ultimum) voldoende geremd, maar niet volkomen onderdrukt werden. Het remmingspercentage was vergelijkbaar met dat van 0.5% ossegal, hoewel dit laatste sommige soorten volkomen onderdrukte; Solacol remde alleenGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum enRhizoctonia solani zeer sterk. In een volgend experiment werden de componenten van Solacol t.o.v. 22 fungi apart getoetst in concentraties equivalent aan 0.33% Solacol. Validamycine remde alleenChaetomium globosum en twee basidiomyceten behoorlijk, maar nauwelijks meer dan de niet-ionische uitvloeier, die in hoofdzaak de overige remeffecten veroorzaakte. Enkele soorten werden echter door het complete Solacol veel sterker geremd dan door de uitvloeier alleen. Solacol in een verdunning van 0,33% wordt aanbevolen bij verdunningsplaten voor het isoleren van grondschimmels ten einde het aantal kolonies en soorten te verhogen.