Monellia costalis (Fitch), a new host forZoophthora radicans (Brefeld) Batko andEntomophthora Planchoniana Cornu (Zygomycetes: Entomophthoraceae) in Israel     

I. Ben-ze’ev  Aviva uziel 《Phytoparasitica》1979,7(3):159-167

Two entomophthoraceous species,Zoophthora radicans andEntomophthora planchoniana, were found on the yellow pecan aphid,Monellia costalis, shortly after it was introduced into Israel. This aphid is a new host forZ. radicans anywhere. The fungus was isolated in pure culture and artificially inoculated on three Dipteran species:Musca domestica, Drosophila melanogaster andCeratitis capitata, as well as on the HemipteranEmpoasca sp. from pecan. The identity ofZ. radicans and some new characters,e.g. the production of two kinds of rhizoids, are discussed. The possibility of usingM. domestica as a vector for artificial spread of the fungus, as a means of biological control of various insect pests, is advocated.  相似文献   

Book reviews     

Joseph Shalhevet  A. Hadas  Marvin E. Jensen  Amir Kassam 《Irrigation Science》1995,16(1):47-51

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Abstracts of papers presented at the second otto warburg symposim on biotechnology: plant - microorganism interaction in the rhizosphere     

A. HüTtermann Marie-Therese Oelbe  E. Fritz  G. Schlechte  A. Bytom  A. D. Jungk  Y. Okon  E. Fallik  Rivka Hadas  S. Sarig  E. Yahalom  Sara Tal  A. Hartmann  B. Kishinevsky  Debora Gurfel  Rina Lobel  Y. Kapulnik  D. A. Phillips  Y. Hadar  Y. Chen  E. Jurkevitch  J. Katan  A. Gamliel  H. Ziegler  I. Chet  A. Ordentlich  Hadar Kless  A. Oppenheim  Avia Zilberstein  D. Holland  J. Berman  A. Zamir  R. Kaufman  N. Bawnik  C. Koncz  J. Schell 《Phytoparasitica》1987,15(2):141-147

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Effect of Azospirillum brasilense inoculation on root morphology and respiration in tomato seedlings     

Rivka Hadas  Yaacov Okon 《Biology and Fertility of Soils》1987,5(3):241-247

Summary The level of Azospirillum brasilense strain Cd colonization in the rhizosphere of some vegetables was 10⁴–10⁵ colony-forming units (CFU) per root of one plant in 2-week-old plants inoculated with 5 × 10⁸ Azospirillum cells. Significant increases in root length (35%) and in top (90%) and root (50%) dry weight and total leaf area (90%) were observed in 18-day-old inoculated tomato plants compared with non-inoculated controls. An inoculum concentration of 1 × 10⁸ to 5 × 10⁸ CFU/ml stimulated the appearance of root hairs. Large numbers of bacteria (1 × 10⁹ CFU/ml) caused asymmetrical growth of the root tip. In a petri dish system, Azospirillum (1 × 10⁸ CFU/ml) increased root dry weight (150%), protein content (20%), respiration rate per root (70%) and the specific activity of malate dehydrogenase (45%–65%) over non-inoculated controls. The specific respiration rate, expressed as micromol of O₂ per minute per milligram of dry weight of roots, was significantly lower in inoculated roots, suggesting that less energy was spent for accumulation of more dry material.  相似文献   

Quantitative analysis of culture using millions of digitized books   总被引：1，自引：0，他引：1  

Michel JB  Shen YK  Aiden AP  Veres A  Gray MK;Google Books Team  Pickett JP  Hoiberg D  Clancy D  Norvig P  Orwant J  Pinker S  Nowak MA  Aiden EL 《Science (New York, N.Y.)》2011,331(6014):176-182

We constructed a corpus of digitized texts containing about 4% of all books ever printed. Analysis of this corpus enables us to investigate cultural trends quantitatively. We survey the vast terrain of 'culturomics,' focusing on linguistic and cultural phenomena that were reflected in the English language between 1800 and 2000. We show how this approach can provide insights about fields as diverse as lexicography, the evolution of grammar, collective memory, the adoption of technology, the pursuit of fame, censorship, and historical epidemiology. Culturomics extends the boundaries of rigorous quantitative inquiry to a wide array of new phenomena spanning the social sciences and the humanities.  相似文献   

The effect of various residue mulch-tillage combinations on soil physical conditions and performance of irrigated cotton     

E. Rawitz  A. Hadas  H. Etkin  M. Margolin 《Soil & Tillage Research》1994,32(4):347-366

Cotton is a major irrigated summer field crop in Israel, and is commonly grown in the same field for 3–5 years in succession. There is only a narrow time window between harvest and early rains for pest control by means of clearing the land surface of residues, and to perform preparatory tillage. The time available may be insufficient to achieve this with the conventional deep plowing tillage system, and some operations may have to be carried out on moist soil between rainfall events. In response to indications of decreasing yield due to compaction, various limited-tillage systems in permanent traffic lanes have been developed, culminating in a machine that performs all residue-disposal and tillage operations in a single pass through the field. A comparison of several limited-traffic and conventional practices was carried out for 2 years on a loessial silt loam (Calcic Haploxeralf). It was found that both soil condition and yield were worst in the two treatments commonly used by farmers: deep plowing and deep incorporation of residues with the combination machine. Tillage effects were dominant, masking any effect of residue amount and disposal method. Large differences were found between the zones of the permanent wheel track treatments, as were cyclic changes in soil condition reflecting the seasonal sequence of tillage operations. Some cumulative compaction occurred, due mainly to a gradual widening of the wheel tracks rather than to repeated passes in the original rut. The findings of this work show that the optimal choice is to replace the previously preferred field practices by shallow slot-mulching with simultaneous subsoiling by the combination machine, which meets the sanitation requirements, maintains satisfactory yields and saves energy and labor.  相似文献   

Rates of decomposition of plant residues and available nitrogen in soil, related to residue composition through simulation of carbon and nitrogen turnover     

Aviva Hadas  Larissa Kautsky  Emine Erman Kara 《Soil biology & biochemistry》2004,36(2):255-266

The dynamics of inorganic N in soil following the application of plant residues depends on their composition. We assumed that all plant materials are composed of similar components, each decomposing at a specific rate, but differ in the proportions of the various components. The NCSOIL model that simulates C and N turnover in soil was used to link the rates of residue decomposition to their composition, defined as soluble, cellulose-like and lignin-like C and N, and thereby integrate short and long-term effects of residues on available N dynamics in soil. Five plant residues in a wide range of C:N ratios were incubated in soil for 24 weeks at 30 °C, during which C and N mineralization were measured. The materials with large C:N ratios (corn, rice hulls and wheat straw) were also incubated with NH₄⁺-N to avoid N deficiency. The residues were analyzed for total and soluble C and N. The partitioning of insoluble C and N between cellulose- and lignin-like pools was optimized by best fit of simulated C and N mineralization to measured results. The decomposition rate constants of the soluble and lignin-like pools were assumed to be 1.0 and 10⁻⁵ d⁻¹, respectively, and that of the cellulose-like pool, obtained by model optimization against mineralization of cellulose with NH₄⁺-N in soil, was 0.051 d⁻¹. The optimized, kinetically defined lignin-like pool of all residues was considerably larger than lignin contents normally found in plant residues by the Van Soest procedure. Gross N mineralization of tobacco and rape residues was similar, but N recovery from tobacco was larger, because a larger fraction of its C was in the lignin-like pool. N in rice hulls, corn and wheat residues was mostly recalcitrant, yet rice hulls did not cause N deficiency, because most of its C was recalcitrant too. The soluble components of the residues had strong short-term effects on available N in soil, but the cellulose-like pool was equally important for short and medium-term effects. Soluble and cellulose-like C were 29 and 42% of total C, respectively, in corn and 7 and 50% in wheat. Maximal net inorganic N losses, measured in both residue treatments after 2 weeks, were 42 mg g⁻¹ C applied as corn and 31 mg g⁻¹ C applied as wheat, or 84 and 110 mg g⁻¹ decomposed C of corn and wheat, respectively. Rice hulls immobilized N slowly, but by the end of 24 weeks all three residues immobilized 26-27 mg N kg⁻¹ C applied. The different dynamics of N immobilization demonstrated the need to determine the decomposability of C and N rather than their total contents in plant residues.  相似文献   

Advances in modeling machine-soil-plant interactions     

A. Hadas  W.E. Larson  R.R. Allmaras 《Soil & Tillage Research》1988,11(3-4)

Modern agriculture involves mechanized operations which affect crop growth and yields through changes in the soil environment. Field research to study the phenomena involved in the soil-machine-crop system is usually site-specific with respect to edaphic, climatic and management factors. Field experiments are often expensive to conduct, and generalization to other sites or practices is usually tenuous at best. Computer-based techniques to simulate machine-soil-plant (or crop) systems can test many combinations of site characteristics and management practices, and screen the most promising combinations. Once these promising combinations are validated, the simulation techniques, together with stochastically-supported data bases can be used to predict tillage management systems suitable for specific sites and crops.Current efforts to model plant response to soil conditions created by tillage and machines have serious shortcomings, because the link between tool action, subsequent soil structure, and the parameters that describe fluxes of water, heat and gas need further development for deterministic modeling. Machine-soil models focus on efficiency of the tillage operation, while soil-plant models focus on soil structure and related parameters influencing plant growth. While current models for simulating the machine-soil-crop system have limitations, an approach to bridge between the two model applications offers great promise and should be a high research priority. When used with improved measurements of tool action and of soil structural properties before and after tillage and traffic, including position or placement of the crop residues, current models can be doubly effective for improving tillage management.  相似文献   

Field studies of the immunisation of lambs with drug-abbreviated infections of Trichostrongylus colubriformis and Ostertagia circumcincta     

M. Stankiewicz  E. Hadas 《New Zealand veterinary journal》2013,61(5):182-184

Fifty, 5–6 month-old lambs were randomly allocated to five equal groups. Three groups of lambs were immunised by three oxfendazole-abbreviated (artificial) infections of Trichostrongylus colubriformis and Ostertagia circutncincta. Group 1 was immunised with a high dose of larvae, Group 2 with a medium dose and Group 3 with a low dose. A fourth group was treated with oxfendazole only and a fifth group was not treated (control). All groups were grazed together on pasture naturally contaminated with nematode larvae. Immunisation significantly reduced the number of eggs per gram of faeces in all three groups, but the lowest faecal egg count was seen in Group 3 (immunised with the lowest number of larvae). Significantly better liveweight gains and wool weight were observed in Group 2 animals than in the control group. Of all anthelmintic-treated animals, only Group 1 lambs did not have a signscantly lower dag weight than controls.  相似文献   

Strategies and priorities in field collections for ex situ conservation: the case of the Israel Plant Gene Bank     

Oz Barazani  Einav Mayzlish-Gati  Dikla Lifshitz  Rivka Hadas  Alexandra Keren-Keiserman  Sivan Golan  Tomer Faraj  Alon Singer  Andrey Beerman  Avi Perevolotsky 《Genetic Resources and Crop Evolution》2017,64(1):1-5

The ex situ collection of the Israel Plant Gene Bank (IGB) aims to encompass the rich local flora and its genetic diversity with an emphasis on crop wild relatives. However, to properly establish a core collection, collection efforts must be prioritized and strategized. We previously classified local plant genetic resources into four priority groups that assisted in strategizing the collection activities. The following years of intensive collection activity yielded over 4200 banked accessions. However, these do not necessarily represent the distribution range of the target species for collection (TSC) and consequently, their genetic diversity. To best cover the latter, the collecting area was divided into botanical districts and the magnitude of the collection was determined according to prioritization group, e.g., a wild relative of an agricultural crop with a vast distribution range should be represented by a larger number of banked accessions than one with a smaller range. Continuous evaluation of specific needs shapes the collection scheme of the IGB to maximize collection efforts, better represent the presumed genetic diversity of TSC, and establish its core collection.  相似文献