垄畦覆膜种行覆土党参种苗移栽机的设计与试验

针对党参覆膜移栽无机可用的问题,结合西北黄土高原旱区党参垄畦覆膜、种行覆土抗逆栽培模式,设计了一种具有开沟、播苗、起垄、整形、覆膜、种行覆土功能的党参种苗移栽机。对样机关键部件进行了分析与设计,确定了尖角长翼型开沟器、整形镇压、膜上覆土等装置的结构及工作参数,解析了核心部件作业机理。田间试验表明,设计的垄畦覆膜、种行覆土党参种苗移栽机埋苗率为4.1%,露苗率为2.6%,栽植合格率为92.0%,栽植深度合格率为87.5%,膜边覆土厚度合格率为95.9%,膜边覆土宽度合格率为96.3%,生产率约为0.14 hm~2·h~(-1)。田间性能试验指标均达到国家和行业标准要求,试验结果满足设计要求。     

蔬菜钵苗大垄双行膜上种植复式移栽机设计与试验

针对平原大垄双行覆膜种植模式，研制了一种适合蔬菜钵苗大垄双行栽植的复式联合作业移栽机，对移栽机栽植机构的栽植轨迹和投苗机构的开闭控制参数进行了设计和优化，同时针对传统农机装备地轮深度调控装置难以满足大垄双行膜上栽深精确控制的难题，设计了一种基于可编程控制器的液压栽深仿形装置并整合到移栽机，使得整机可一次性完成旋耕起垄、垄上覆膜、双行独立仿形、膜上Z字形移栽等多道作业工序。分别在45、60株·min^-1的栽植频率条件下进行移栽试验，田间试验结果表明：株距合格率、移栽合格率的平均值分别为94.08%、90.45%和91.90%、88.33%,平均栽深合格率为94.15%,较好地满足了蔬菜钵苗大垄双行种植要求。     

吊杯式栽植器运动轨迹优化与试验

针对吊杯式移栽机膜上成穴移栽时膜面穴口大的问题,建立栽植机构的运动模型,通过分析栽植器的运动轨迹特性得出,当栽植器的运动轨迹为余摆线,且余摆线环扣最大横弦的距离等于轨迹线与地膜交点间的距离,栽植器在上拔阶段水平方向零速度点两侧打开,有利于减小膜面穴口尺寸。通过仿真分析和膜上移栽番茄盘苗试验得出,运动轨迹特征系数λ对膜面穴口的纵向尺寸影响显著,对横向尺寸和倾斜率影响不明显。随着λ值的增大,穴口纵向尺寸先减小然后增大,在移栽频率为50和55株·min^-1时,λ为1.093的穴口纵向尺寸分别为10.12 cm和9.49 cm,是最小值; 两种移栽频率条件下,随着λ值的增大,移栽株距分别从39.8 cm减小到33.5 cm和从39.1 cm减小到33.1 cm。该结论可用于指导吊杯式移栽机结构和工作参数的优选。     

基于五连杆移栽机构的自定深仿形装置设计与试验

针对现有钵苗移栽机在起伏垄面作业时栽深控制稳定性低的问题,采用栽植器仿形方法,以可编程机床控制器(program machine control)为核心,设计了自动精准定深仿形装置以实现对每行栽植器独立主动仿形。通过理论分析确定自定深仿形装置关键结构与扭矩、升降速度等参数,并设计了自定深移栽试验台。运用正交试验优化方法,研究该仿形机构作业速度、升降速度和移栽株距参数变化与栽深合格率关系。通过Box-Benhnken组合试验,得到影响栽植深度合格率的各因素由大到小为移栽株距、升降速度、作业速度。通过软件寻优得到栽深合格率最高条件下的最佳参数组合为作业转速180 mm·s~(-1)、升降速度142 mm·s~(-1)、移栽株距195 mm。台架试验表明,采用自定深仿形装置后的平均栽深合格率为91.9%,具有田间实际应用价值。     

张掖市番茄茎基腐病田间发病规律及防治方法研究

田间调查表明,番茄茎基腐病在张掖市发病初期为5月中、下旬,发病高峰期在6月中、下旬;移栽发病重,直播发病轻;碱潮地发病重,其次为灌漠地,沙壤地发病率最轻;平作发病重,垄作发病轻;膜面覆土发病轻,膜面不覆土发病重;中间破膜发病轻,中间不破膜发病重。根据种子、苗床处理、定植穴以及发病初期药剂灌根试验结果表明:供试的10种药剂中,以3%口恶霉.甲霜水剂400倍液移栽前灌根、45%敌磺.琥铜可湿性粉剂750倍液发病初期灌根,防效分别为65.5%、59.5%。     

跨越式膜上覆土装置的参数仿真设计与试验

针对全膜种植模式中覆土装置覆土质量差引起的易受风力破坏、烧苗、出苗受阻等问题,设计了一种适用于全膜覆土机具的跨越式刮板升运链膜上覆土装置。为提高覆土机构的工作性能,构建了覆土装置的实体模型,运用离散单元法模拟仿真试验,结合Box-Behnken试验设计原理,采用三因素三水平响应曲面法,借助DesignExpert软件处理试验结果,建立了覆土宽度和覆土厚度合格率的二次回归模型,分析各因素交互作用对试验指标的影响,优化得到最佳参数组合,即链速与机组前进速度比为1.38、排土口高度为200 mm、排土口宽度为120 mm,并依此进行田间验证试验。试验结果表明,用离散单元法模拟出的覆土宽度值和覆土厚度合格率接近田间重复试验均值,且满足农艺要求。     

旱地小麦全膜覆土播种一体机的研制

旱地小麦全膜覆土播种一体机是针对全膜覆土穴播技术而研制的,该机可一次性完成旋耕、镇压、铺膜、覆土、播种等工序。该机采取旋耕抛土与铲土板相配合的取土方式,保证了充足的土壤来源,设计了输送带链传动的输土装置、外槽轮式覆土装置,实现了膜上均匀覆土和覆土厚度的控制。设计了仿形机构,实现了穴播装置的地面仿形,并对仿形机构进行动力学仿真,分析了仿形机构的仿形效果。通过样机田间试验测定,覆土厚度的平均值为1.074 cm,覆土宽度的平均值为121.283 cm符合农艺要求,覆土的厚度、宽度的变异系数分别为23.37%和0.96%,符合设计要求。通过实验测定,旋耕镇压后的土壤容重和土壤孔隙度符合农艺要求。     

防护条件下梭梭幼苗生长及养分吸收特性

以新疆古尔班通古特沙漠南缘管件防护与传统移栽2种方式移栽的梭梭幼苗为实验材料,通过野外监测与室内分析,探讨了管件防护条件下梭梭幼苗的生长及养分吸收特性。结果表明:整个生育期内,管件防护梭梭幼苗的各生长指标与传统移栽苗相比,增幅最大的为茎粗,其次为株高。年周期内管件防护梭梭幼苗的生物量呈递增趋势,单株生物量累积可达45.25 g·株~(-1);净增加27.10 g·株~(-1),是传统移栽苗的1.38倍(P0.05)。管件防护梭梭幼苗体内的氮素、磷素、钾素含量呈先升高后降低趋势,在同化枝生长期达到峰值,分别为11.376 g·kg~(-1)、1.066 g·kg~(-1)和23.340 g·kg~(-1),较传统移栽苗高24%、15%和8%,差异显著;而其梭梭幼苗氮素、磷素、钾素的总积累量却呈递增趋势,年净增积累量分别为0.297 g·株~(-1)、0.027 g·株~(-1)和0.560 g·株~(-1),是传统移栽苗的2.23倍、1.72倍和1.65倍;各时期梭梭幼苗体内的氮素、磷素、钾素含量及总积累量均高于传统移栽苗。     

全膜双垄沟播起垄施肥铺膜机的研制

针对全膜双垄沟播种植的农艺要求,研制了一种起垄施肥铺膜机,可完成起垄、施肥、喷药、铺膜和覆土压膜联合作业。用旋耕方式整地起垄,覆土装置实现地膜纵向两边均匀覆土和地膜横向间隔覆土。采用旋耕前喷药和铺膜前施肥的作业方式,保证药效和肥效最大限度地发挥作用。试验表明,垄面光滑,无明显缺陷且覆土后的地膜无机械破膜现象。膜横向覆土距离的平均值为102 cm,纵向覆土厚度和宽度的平均值为5.1 cm和11.4 cm,大垄的垄宽和垄高的平均值分别为69.3 cm和14.9 cm,小垄的垄宽和垄高的平均值为40.5 cm和15.2 cm,满足全膜双垄沟播种植农艺要求。覆土的厚度、宽度的变异系数分别为4.83%和7.52%,大垄宽度、高度的变异系数为1.22%和2.14%,小垄宽度、高度的变异系数为2.26%和1.58%,符合设计要求。     

机械插秧大田管理

机械插秧是小苗带土移栽,插秧深度浅而一致,株行距规格标准统一,能使基本苗数得到保障,宽行、密株,有利于通风透光及发挥边际效应,有利于田间管理。机械插秧的插后管理上相对手工插秧而言,要注意6个环节：（1）湿润立苗：由于移栽时秧苗较小,移栽后一周内抗逆性比手插大苗要差,要精细管理,不能干旱,也不能淹水过深。（2）及时除草：由于秧苗小,     

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.     

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.     

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.     

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.     

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 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.     

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     

Broad bean mottle virus in Morocco; curculionid vectors,and natural occurrence in food legumes other than faba bean (Vicia faba)

Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.     

Characterization of potato potyvirus Y (PVY) isolates from seed potato batches. Situation of the NTN, Wilga and Z isolates

A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVY^N strain and six to the PVY^O strain. No PVY^C was found. Two other isolates reacted serologically like PVY^O, but were unable to elicit a hypersensitive response from the Ny_tbr gene and probably represent the PVY^Z group. At the molecular level, these two isolates showed a combination of both PVY^O and PVY^N and could be recombinants of these strains. Another isolate reacted serologically like PVY^O, but induced vein necrosis in tobacco, like PVY^N-Wilga. Some PVY^N isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVY^NTN group. The PVY^NTN, PVY^N-Wilga and PVY^Z groups probably represent pathotypes within strains PVY^N and PVY^O, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.