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Letnik 85

Ljubljana, 2005

Številka 1


Scientific and technical information on organic farming: assessment of selected bibliographic indicators in database CAB Abstracts

 Tomaž BARTOL, Špela DRNOVŠEK, Majda ČERNIČ-ISTENIČ

 ABSTRACT

 We scientometrically examined selected publishing patterns in organic farming as indexed by database CAB Abstracts (CABA) in the period 1973-2003. Some characteristics of CABA were also established. 4,170 records of all types (2,740 journal articles, 1,165 conference papers etc.) were harvested with the employment of descriptors derived from the CAB Thesaurus. The journal articles were further analyzed for yearly growth, languages, authorship, and geographic location. Growth has accelerated during the last ten years. English prevails among the 31 retrieved languages, with some 50 % citations, followed by German, Italian, French, and Japanese. A few highly productive authors (among the 4,304 different authors), with some publishing as many as 18 articles, accounted for the core of documents, whereas as many as 3,438 authors contributed only one article in the entire period. Germany was most frequently indexed as a geographic-location-descriptor, followed by Italy, U.K., Denmark, and Switzerland. This descriptor field, however, is not employed consistently so the geographic data must be interpreted with caution. This analysis is based mostly on descriptor Organic farming so some other terms could possibly also be employed to retrieve more documents related to this field of research.

 znanstvene in strokovne informacije o ekološkem kmetijstvu: ocena izbranih bibliografskih indikatorjev v zbirki cab abstracts

izvleček 

Scientometrično smo ovrednotili značilnosti objav za ekološko kmetijstvo po podatkih iz zbirke CAB Abstracts (CABA) v obdobju 1973-2003. Pri tem smo ocenili smo tudi nekatere značilnosti same zbirke. Zbrali smo 4.170 zapisov vseh tipov (2.740 člankov iz revij, 1.165 prispevkov s posvetovanj ipd.) s pomočo deskriptorjev iz tezavra CAB. Članke smo nadalje analizirali glede na letno rast, jezik, avtorstvo in geografsko lokacijo. Rast se pospešuje zadnjih deset let. Med 31 različnimi jeziki prevladuje angleščina (50 % dokumentov); sledijo nemščina, italijanščina, francoščina in japonščina. Nekaj posameznih visoko produktivnih avtorjev (med 4.304 različnimi avtorji), od katerih je en napisal kar 18 člankov, je prispevalo pomemben delež vseh dokumentov, kar 3.438 pa je bilo takih, ki so prispevali le po en članek. Najpogosteje rabljeni deskriptor pri geografski lokaciji je bila Nemčija, sledila je Italija, Združeno kraljestvo, Danska in Švica, vendar pa se to deskriptorsko polje v zbirko ne vnaša konsistentno, zato je treba geografske podatke interpretirati s pazljivostjo. Analiza temelji pretežno na deskriptorju Organic farming, zato je potrebno upoštevati, da je v zbirki verjetno najti še precej drugih dokumentov, ki bi vsebinsko tudi ustrezali temu pojmu, a z njim niso bili indeksirani.

 

Impact of enrichment medium on PCR-based detection of Listeria monocytogenes in food

 Barbara Jeršek, Tamara Majstorović, Nataša Klun, Sonja Smole Možina

 ABSTRACT

 The detection of Listeria monocytogenes in food samples using enrichment and PCR is described. The objectives were to determine whether the type of enrichment medium has the influence on the results obtained with PCR and to evaluate proposed method by analysing naturally contaminated food samples. Comparative evaluation of different enrichment media for bacteria of the genus Listeria (half Fraser - HF, buffered peptone water - BPW, triptic soy yeast extract broth -  TSBYE, universal preenrichment broth - UPB) showed that only the UPB enabled detection of L. monocytogenes in artificially contaminated food samples after 24h of incubation. The PCR-based method gave equal results as standard cultural method by analysis of naturally contaminated food samples. Described PCR-based procedure is comparable to some other PCR-based methods of L. monocytogenes detection in foods and shows promise as a rapid, routine method which requires 30-72 h, whereas cultural methods require 96-120 h.

 VPLIV OBOGATITVENEGA GOJIŠČA NA DOLOČANJE BAKTERIJ VRSTE Listeria monocytogenes V ŽIVILIH S PCR

 IZVLEČEK

 V prispevku je predstavljen postopek določanja bakterij vrste L. monocytogenes v živilih s PCR po obogatitvi vzorca živila. Namen raziskave je bil določiti, ali vrsta obogatitvenega gojišča vpliva na rezultate PCR, in vrednotenje predlagane metode s preiskavami naravno kontaminiranih živil. Primerjava različnih obogatitvenih gojišč za bakterije rodu Listeria (half Fraser - HF, buffered peptone water - BPW, triptic soy yeast extract broth -  TSBYE, universal preenrichment broth - UPB) je pokazala, da edino gojišče UPB omogoča določitev bakterij vrste L. monocytogenes v umetno kontaminiranih vzorcih živil po 24-urni inkubaciji. Rezultati določanja bakterij vrste L. monocytogenes v naravno kontaminiranih vzorcih živil dobljeni po obogatitvi s PCR so bili enaki rezultatom dobljenim s standardno gojitveno metodo. Opisana metoda PCR je primerljiva s podobnimi metodami, ki temeljijo na isti encimski reakciji in omogoča hitro, rutinsko določanje bakterij vrste L. monocytogenes v živilih v 30-72 urah, medtem ko je za rezultate gojitvenih metod potrebno 96-120 ur.

 

Podnebne spremembe in ranljivost kmetijstva

 Lučka KAJFEŽ-BOGATAJ

  IZVLEČEK

 Globalno ogrevanje našega planeta postaja fizikalno izmerjeno dejstvo. Mnenje klimatologov je, da se bodo spremembe podnebja nadaljevale še bolj izrazito, saj bo prišlo do sprememb v celotnem klimatskem sistemu, ki ga sestavljajo poleg atmosfere še hidrosfera, kriosfera, biosfera in njihove interakcije. Spremenjene temperaturne razmere in razporeditev padavin, kakor tudi spremembe drugih meteoroloških spremenljivk, bodo vplivale na vsa področja človekovega delovanja. Kmetijstvo je kompleksno odvisno od vremenskih in klimatskih danosti in je v zvezi s podnebnimi spremembami močno ranljivo. Podnebne spremembe bodo lahko pozitivno ali negativno vplivale tako na rastlinsko kot živinorejsko pridelavo. Najbolj je kmetijstvo ranljivo zaradi ekstremnega vremena, kamor štejemo zlasti suše, poplave, neurja s točo, pa tudi nizke temperature s pozebami ter vročinske valove. Pogostnost ekstremnih vremenskih dogodkov se bo povečala, regionalno pa se bo ob zvišani temperaturi zraka različno spreminjal padavinski režim. Ker bodo med učinki podnebnih sprememb na kmetijstvo prevladovali negativni, je nujno, da se kmetijstvo čimprej začne prilagajati napovedanim podnebnim spremembam. Prilagoditve pa so povezane ne le z odločitvami in ukrepi posameznega kmeta, temveč tudi s kmetijsko politiko, tržnimi mehanizmi ter razvojnimi in tehnološkimi raziskavami.

 ABSTRACT

CLIMATE CHANGE AND AGRICULTURE VULNERABILITY

Global warming is no longer just a theory or a distant threat. The overwhelming agreement among the world’s preeminent climate scientists is that its impact can already be seen today and may grow worse in the future. This global warming is expected to significantly disrupt the climate system. As a result, regional temperatures and precipitation patterns will shift across the globe, affecting nearly every aspect of society. The linkages between agriculture and climate are pronounced and often complex. Crops and livestock are sensitive to climate change in both positive and negative ways. Agricultural systems are most sensitive to extreme climatic events such as droughts, floods and hail storms, and to seasonal variability such as periods of frost, cold or high temperatures, and changing rainfall patterns. Climate change could alter the frequency and magnitude of extreme events and could change seasonal patterns in both favorable and unfavorable ways, depending on regional conditions. Regional patterns of agriculture production are likely to change. Agriculture is fortunately a sector that can adapt but farmer adaptations are influenced by many factors, including government agricultural policy, prices, technology research and development, and agricultural extension services.

 

 Podnebne spremembe in njihovi vplivi na kakovost življenja ljudi

 gLučka KAJFEŽ-BOGATAJ

 IZVLEČEK

 Podnebne spremembe bodo vplivale na počutje in zdravje ljudi ter v splošnem na kakovost življenja, zato je preučevanje teh učinkov pomeben izziv za znanstvenike. Možne posledice podnebnih sprememb za zdravje ljudi bodo odvisne tako od velikosti in poteka podnebnih sprememb kot tudi od socio-ekonomskih dejavnikov. Glavni neposredni dejavnik, ki bo povzročal ranljivost na podnebne spremembe, bo povečana pogostnost in intenzivnost ekstremnih vremenskih dogodkov (poplave, neurja, suše). To bo povzročalo materialne škode, selitve prebivalstva, pomanjkanje hrane in vode, povečano smrtnost in širjenje bolezni. Ženska populacija bo bolj ranljiva. Vročinski valovi bodo usodni predvsem za stararostnike, kot bilo razvidno v Evropi poleti 2003. Povečana koncentracija CO2 in višje temperature bodo spodbudile rast alergogenih rastlin in podaljšale pelodno sezono. Podnebne spremembe bodo ogrožale tudi socio-ekonomski razvoj, demografske tokove, turizem in zdravstveno infrastrukturo. Učinski podnebnih sprememb bodo še posebej izraziti v velikih mestih, obalnih področjih in v gorskem svetu.

 ABSTRACT

CLIMATE CHANGE IMPACTS ON QUALITY OF HUMAN LIFE

 Global climate change affecting patterns of human health and quality of life in general poses a central challenge to scientists and policymakers. Impacts of climate change on human health will depend on the type, intensity, frequency and distribution of the climatic hazards and on the social vulnerability of the population. There is increasing evidence on the pathways on how climate variability and change affect health. Quality of life is directly tied to regional increases in climate extremes (storms, floods, cyclones) which will cause physical damage, population displacement, and adverse effects on food production, freshwater availability and adverse health effects such as deaths, cardio vascular and respiratory morbidity and infectious or food borne disease outbreaks. Women tend to be more vulnerable and marginalized. Heat-waves cause significant mortality in the aging populations as has been shown in the European heat-wave in 2003. Increased concentrations of carbon dioxide and increases in temperature are projected to increase the growth rate of allergen-producing plants and the length of the pollen season. Climate change may also affect demographic shifts, socio-economic development, tourism and health services infrastructure. There are areas where the impacts might be higher: urban areas, coastal and low lying areas and mountainous areas.

 

Senzorična analiza: metode in preskuševalci

 Terezija GOLOB, Mojca JAMNIK, Jasna BERTONCELJ, Urška DOBERŠEK

 Izvleček

 Senzorična analiza je definirana kot znanstvena disciplina prepoznavanja in opisovanja senzoričnih lastnosti, zaznanih s človekovimi čuti. Obsega zaznavanje prisotnosti ali intenzivnosti različnih senzoričnih lastnosti, razlikovanje v zaznavanju in kvantitativno ocenjevanje. Senzorično analizo lahko izvajajo trije tipi senzoričnih preskuševalcev: preskuševalci začetniki, izbrani preskuševalci in izvedenci. Panel je skupina preskuševalcev, izbranih in usposobljenih za delo na določenem senzoričnem preskusu. Kakšen postopek oziroma senzorično metodo bomo izbrali, je odvisno od namena ocenjevanja, vrste, narave in števila izdelkov in usposobljenosti preskuševalcev. Izbiramo lahko med hedonskimi in analitičnimi preskusi. Hedonske preskuse uporabimo pri ugotavljanju stopnje sprejemljivosti in dajanju prednosti, analitične pa za ugotavljanje razlik in merjenje specifičnih senzoričnih lastnosti izdelka. Pri tem moramo razlikovati med: preskusi razlikovanja, ki so pri senzoričnem ocenjevanju široko uporabni in omogočajo določitev majhnih razlik med dvema izdelkoma; preskusi z uporabo lestvic, ki se uporabljajo za določanje intenzivnosti razlik ali za uvrščanje vzorcev v kategorije oziroma razrede; opisno analizo, ki jo, kot najbolj izpopolnjeno senzorično tehniko, lahko izvajajo le eksperti in omogoča popoln opis vseh zaznanih senzoričnih lastnosti, v takem vrstnem redu, kot jih zaznamo.

 Abstract

 SENSORY ANALYSIS: METHODS AND ASSESSORS

 Sensory analysis is defined as a scientific discipline of highlighting and describing the sensory properties that are perceived by sense organs. It comprises the perception of the presence, or intensity of perceived properties, or the differentiation of perception and quantitative assessment. Three types of assessors may perform sensory assessment: assessors, selected assessors, and experts. Panel is a group of assessors chosen for participation in an analytical test. Sensory evaluation includes examination of the sensory properties of a product by the sense organs with one of the following methods: hedonic tests for measuring liking and preference of a product, and analytical techniques for measuring or comparing the sensory characteristics of a product, respectively. A distinction should be made between them. Discriminative methods are widely used in the sensory evaluation and are designed to detect small differences between two products. Scaling and ranking methods are used to estimate the order or size of differences, or the categories or classes to which samples should be allocated. Descriptive analysis is the most sophisticated sensory method, and comprises the process of describing the perceived sensory characteristics of a product, usually in the order of their occurrence.

 

Induction of Hsp104 by Cr(VI) in yeast Candida intermedia

Polona JAMNIK, Peter RASPOR

 ABSTRACT

 The synthesis of a polypeptide family named heat shock or stress proteins is one of the most conserved mechanisms of cellular protection in the case of changes in the environment. Among them Hsp104 is important, because it promotes survival of cells under extreme stresses such as high temperatures, severe oxidative damage and high concentrations of ethanol. The aim of our research was to investigate whether Hsp104 is induced in the yeast Candida intermedia exposed to Cr(VI). Namely, Cr(VI) belongs to redox active metals, which play an important role in the generation of reactive oxygen species in the cell and therefore they can lead to oxidative damages. Yeast cells were treated with Cr(VI) in the mid-exponential phase and after a defined time of incubation, Hsp104 induction was investigated by using Western blotting. Results showed that cultivation of yeast cells in the presence of 100 mM Cr(VI) caused induction of Hsp104, which is connected to formation of protein aggregates. Hsp104 assists their resolubilization and so contributes to cell survival. Its synthesis was detected 0.5 h after Cr(VI) addition and was later for up to 2 h more apparent. Therefore, we showed that Hsp104 plays an important role in the stress response of yeast Candida intermedia to Cr(VI).

 IZVLEČEK

 INDUKCIJA Hsp104 S Cr(VI) PRI KVASOVKI Candida intermedia

 Sinteza družine polipeptidov, ki jih imenujemo proteini toplotnega šoka ali stresni proteini, je eden izmed  najbolj ohranjenih mehanizmov celične zaščite pri spremembah v okolju. Med njimi je pomemben Hsp104, ki omogoča preživetje celic v ekstremnih stresnih pogojih, kot so visoke temperature, močne oksidativne poškodbe in visoke koncentracije etanola. Namen naše raziskave je bil preučiti, če Cr(VI) povzroči indukcijo sinteze Hsp104 v kvasovki Candida intermedia. Cr(VI) namreč sodi med redoks aktivne kovine, ki imajo pomembno vlogo pri nastanku reaktivnih kisikovih zvrsti v celici in lahko vodijo do nastanka oksidativnih poškodb. Celice smo izpostavili Cr(VI) v sredini eksponentne faze rasti in po določenem času inkubacije preverjali indukcijo Hsp104 z analizo proteinov western. Rezultati so pokazali, da kultivacija celic v prisotnosti 100 µM koncentracije Cr(VI) povzroči indukcijo Hsp104, kar je povezano s tvorbo proteinskih agregatov. Hsp104 namreč pomaga raztopiti agregate in s tem celicam omogoči preživetje. Sinteza Hsp104 se je pojavila že 0,5 h po dodatku Cr(VI), kasneje tja do dveh ur pa se je še povečala. V raziskavi smo pokazali, da ima Hsp104 pomembno vlogo v stresnem odgovoru kvasovke na Cr(VI).

 

Conservation of natural ecosystems by land consolidation in the rural landscape

 Anka Lisec, Marina PINTAR

 ABSTRACT

 Protecting the environment better livelihoods in rural communities have become increasingly important elements in land consolidation. The main objective of land consolidation is to improve the land holdings of farmers by concentrating their farms in as few plots as possible, and to support the farms with roads and infrastructure when needed. Experiences from the Western European countries and also from Slovenia show that land consolidation, which solely focuses on increase in productivity without taking into consideration the ecological aspects easily lead to negative effects. The fragmentation of natural ecosystems resulting from inappropriate land consolidation has been recognised as one of the major causes of the decline of biodiversity, the others being erosion, and the lowering of water table. In the areas of intensive agricultural production ecological structures, such as hedges, small areas of bushes, trees and water holes should be preserved. Because the efficiency of land utilisation increases after the implementation of land consolidation, the small land areas could be justified to ecological land use.

 IZVLEČEK

 OHRANJANJE NARAVNIH EKOSISTEMOV PRI ZLOŽBI ZEMLJIŠČ V KMETIJSKI KRAJINI

 Sonaravno urejanje kmetijskih zemljišč ob upoštevanju ekoloških meril predstavlja danes pomembno smernico pri izvajanju komasacij kmetijskih zemljišč. Osnovni namen komasacije kmetijskih zemljišč je izboljšanje posestne in zemljiške strukture in s tem posredno povečanje kmetijske pridelave, hkrati pa se nanaša na urejanje potrebnih dostopnih poti in druge infrastrukture v kmetijski krajini. Komasacije kmetijskih zemljišč v nekaterih zahodnoevropskih državah in tudi v Sloveniji, ki so bile osredotočene le na povečanje kmetijske proizvodnje, zanemarjeni pa so bili ekološki vidiki, so mnogokrat prinesle več škode kot koristi. Neprimeren pristop h komasacijam kmetijskih zemljišč in s tem povezano drobljenje in krčenje naravnih ekosistemov so lahko vzrok za povečanje občutljivosti zemljišč na erozijo rodovitnih tal, na sušna obdobja in za izginevanje številnih rastlinskih in živalskih vrst v kmetijski krajini. Na območjih z intenzivno kmetijsko pridelavo bi se morali ohranjati ekološki elementi, kot so obmejki, grmičevje, mlake ipd. S komasacijami kmetijskih zemljišč se uniči veliko takih ekoloških elementov, ki bi jih morali vsaj delno ohraniti, del pa nadomestiti z novimi ekološkimi površinami.

 

Water Balance Assessment for Lysimeter Station based on Water Pumping Station Kleče in Ljubljana

 Vesna Zupanc, Branka Bračič-Železnik, Marina Pintar

 ABSTRACT

 For soil water balance calculation two lysimeters were built on Water Pumping Station of Public Water Supply Company in Ljubljana. Soil water balance (change in storage) was calculated using precipitation, evapotranspiration, and lysimeter outflow. Outflow measurements systematically showed discrepancy between Lysimeter North and Lysimeter South, in average 300 mm/year. Yearly soil water balance calculation for the Lysimeter North shows slight decrease in water storage every year in studied period (2001 – 2004).

 IZVLEČEK

 OCENA VODNE BILANCE ZA LIZIMETRSKO POSTAJO PRI VODARNI KLEČE V LJUBLJANI

 Na črpališču Kleče javnega podjetja Vodovod-Kanalizacija Ljubljana sta bila zgrajena dva lizimetra za ugotavljanje vodne balance tal. S pomočjo padavin, evapotranspiracije in iztoka iz lizimetra smo izračunali vodno bilanco tal (spremembo v zalogi vode v tleh). Meritve iztoka iz lizimetrov so pokazale razliko med severnim in južnim lizimetrom, v povprečju 300 mm na leto. Izračun vodne bilance na letni ravni za severni lizimeter nakazuje rahlo zmanjšanje v zalogi vode v tleh za vsako leto v opazovanem obdobju (2001 – 2004).

 

Effects of rugose wood and GLRaV-1 on yield of cv. ‘Refošk’ grapevines

 Irma TOMAŽIČ, Nataša PETROVIČ, Zora KOROŠEC-KORUZA

 Abstract

 The influences of rugose wood (RW) disease and grapevine leafroll associated Closterovirus 1 (GLRaV-1) on yield in grapevine cv. Refošk were studied. Both diseases were shown to reduce the yield. The grape quality expressed as sugar degree (°Oe) was higher in GLRaV-1 infected vines probably due to lower yield and consequent early ripeness. 18 % of plants with RW symptoms on the rootstock part of the vine have died 10 years after planting.

 IZVLEČEK

 VPLIV BOLEZNI RAZBRAZDANJA LESA TER GLRaV-1 NA PRIDELEK SORTE 'REFOŠK'

 Proučevan je bil vpliv bolezni razbrazdanja lesa ter virusnega zvijanja listov vinske trte (Grapevine leafroll associated Closterovirus 1, GLRaV-1) na pridelek sorte 'Refošk'. Tako GLRaV-1 kot bolezen razbrazdanja lesa vplivata na zmanjšanje pridelka. Kakovost grozdja, izražena v °Oe stopinjah sladkorja, je bila boljša pri trsih okuženih z GLRaV-1, verjetno tudi zaradi manjšega pridelka in posledično hitrejšega dozorevanja grozdja  okuženih trsov. 18 % trsov z boleznijo razbrazdanja lesa, izraženo na podlagah okuženih trsov, je propadlo že 10 let po sajenju.

 

Vpeljava in ovrednotenje metode določevanja mineralnega dušika v tleh

 Veronika KMECL, Lucija ZUPANČIČ-KRALJ

 IZVLEČEK

 Ugotavljanje vsebnosti anorganskega oz. mineralnega dušika (Nmin), ki ga ekstrahiramo iz zemlje z 0,01 M razt. CaCl2, omogoča izboljšanje napovedovanja gnojenja z dušikom. V ta namen smo razvili analitske metode določevanja amonijevih, nitratnih in nitritnih ionov v zemlji. Metode smo verificirali; določili smo točnost, natančnost, mejo zaznavnosti (LOD) in mejo kvantitativne določitve (LOQ). Točnost meritev smo dokazali z uspešnim sodelovanjem laboratorija v mednarodni medlaboratorijski primerjalni shemi WEPAL (Wageningen Evaluating Programme for Analytical Laboratories, Nizozemska). Natančnost meritev (ponovljivost in obnovljivost) smo izrazili z relativnim standardnim odmikom (RSD), ki je bil v vseh primerih pod 2%. Vrednosti LOD in LOQ za nitratni dušik sta bili 0,05 mg/kg oz. 0,18 mg/kg in za amonijski dušik 0,09 mg/kg oz. 0,31 mg/kg.

 ABSTRACT

 INTRODUCTION AND VERIFICATION OF METHODS USED FOR DETERMINATION OF MINERAL NITROGEN IN SOIL

 Determination of inorganic or mineral nitrogen content (Nmin), extracted from the soil with the 0.01 M CaCl2 solution, enables improvements of fertilization recommendations with nitrogen. For this purpose we have developed analytical methods for determination of ammonium, nitrate and nitrite ions in the soil. The methods were verified; trueness, precision, limit of detection (LOD) and limit of quantification (LOQ) were determined. The trueness of measurements was proofed by successful participation of our laboratory in the international interlaboratory exchange programme WEPAL (Wageningen Evaluating Programme for Analytical Laboratories, Netherland). The precision of measurements (repeatability and reproducibility) was expresed as relative standard deviation (RSD) which was under 2% in all cases. The values of LOD and LOQ were 0,05 mg/kg and 0,18 mg/kg respectively for nitrate nitrogen and 0,09 mg/kg or 0,31 mg/kg for ammonium nitrogen.

 

Karakteristike sojeva Phomopsis sp. izolovanih iz izdanaka obolele maline

Momčilo ARSENIJEVIĆ

 IZVOD

 Ukazano je na pojavu Phomopsis sp. izolovanog iz izdanaka obolele maline. Date su karakteristike razvoja dva soja ove gljive pri gajenju na hranljivoj podlozi. Istaknuto je i njihovo ponašanje pri veštačkoj inokulaciji plodova jabuke i višnje kao i izdanaka kupine u odsustvu maline. Podloge od graška, crnog luka i krompir-glukozna (PDA) pogodan su hranljivi supstrat za razvoj kolonija, stvaranje piknidskih stroma i α i β-piknospora. Temperaturni optimum za porast kolonija i fruktifikaciju parazita je 15o-25o C.

 IZVLEČEK

 KARAKTERISTIKE SOJEV Phomopsis sp. IZOLIRANIH IZ POGANJKOV OBOLELE MALINE

 Phomopsis sp. je bil izoliran iz poganjkov obolele maline. Ugotovljene so lastnosti dveh sojev glive, članek poroča o morfoloških lastnostih glive in kultur. Lastnosti sojev so bile raziskane z umetno okužbo jabolk in češenj, kot tudi poganjkov robide namesto maline. Gojišča z grahom, čebulo in krompir-glukozno gojišče (PDA) so primerna za razvoj kolonij, piknidijev ter α in β-piknospor. Temperaturni optimum za rast kolonij in fruktifikacijo parazita je med 15o in 25o C.

 ABSTRACT

 CHARACTERISTICS OF THE Phomopsis sp. STRAINS ISOLATED FROM RASPBERRY CANES DIESEASED

The fungus Phomopsis sp. originating from raspberry canes diseased was isolated and its two strains (Ph-18 and Ph-19) were studied. Their morphological and cultural properties are given in this paper. The pathogenicity of the strains investigated were proved by the artificial inoculation of apple and cherry fruits, as well as using blackberry instead raspberry canes (Figs. 1-10). Pea grain agar, onion and PDA were suitable nutrient source for colony development and the pycnidial stromata and α and β-pycnidiospores production. The temperature optimum for colony growth and pathogen fructification ranged between 15o-25oC.

 

Concentration of suspension and temperature as factors of pathogenicity of entomopathogenic nematodes for the control of granary weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae)

 Stanislav TRDAN, Nevenka VALIČ, Gregor UREK, Lea MILEVOJ

 ABSTRACT

 Efficacy of four species of entomopathogenic nematodes (Steinernema feltiae, S. carpocapsae, Heterorhabditis bacteriophora, H. megidis) for the control of granary weevil adults (Sitophilus granarius) was tested under laboratory condition. Suspensions of nematodes were applied in three concentrations (5.000, 10.000, and 20.000 IJs per ml) at three temperatures (15oC, 20oC and 25oC). After one week mortality of the beetles was assessed. No significant differences in the percentage of mortality were determined between treatments with S. feltiae, S. carpocapsae and H. bacteriophora, while H. megidis was the least efficient. Mortality of the beetles was statistically significantly higher at 20 and 25 oC. Influence of the concentration of the nematode suspension was proved to be less important in biological activity of biological agents in question.

 IZVLEČEK

 KONCENTRACIJA SUSPENZIJE IN TEMPERATURA KOT DEJAVNIKA PATOGENOSTI ENTOMOPATOGENIH OGORČIC PRI ZATIRANJU ČRNEGA ŽITNEGA ŽUŽKA, Sitophilus granarius (L.) (Coleoptera: Curculionidae)

 V laboratorijskih razmerah smo preučevali učinkovitost štirih vrst entomopatogenih ogorčic (Steinernema feltiae, S. carpocapsae, Heterorhabditis bacteriophora, H. megidis) za zatiranje odraslih osebkov črnega žitnega žužka (Sitophilus granarius). Tri različne koncentracije suspenzije (5.000, 10.000 in 20.000 infektivnih ličink/ml) smo aplicirali pri treh različnih temperaturah (15oC, 20oC in 25oC). Po enem tednu smo ugotavljali smrtnost hroščkov. Med vrstami S. feltiae, S. carpocapsae in H. bacteriophora nismo ugotovili značilnih razlik v vplivu na smrtnost hroščkov, vrsta H. megidis pa je v tej zvezi pokazala najmanjšo učinkovitost. Smrtnost hroščkov je bila statistično značilno največja pri temperaturah 20 in 25 oC. Ugotavljamo, da je koncentracija suspenzije, v primerjavi s temperaturo okolja, manj pomemben dejavnik biotičnega delovanja entomopatogenih ogorčic na hroščke črnega žitnega žužka. 

 

Stročnice v kolobarju slovenskih ekoloških kmetij

Darja KOCJAN AČKO, Špelca TOLAR, Igor ŠANTAVEC

 IZVLEČEK

 Analiza prisotnosti stročnic v kolobarju slovenskih ekoloških kmetij temelji na anketah, poslanih 30-im gospodarjem ekoloških kmetij konec leta 2002 in 2004 in na preučitvi sestave kolobarja na treh ekoloških kmetijah na Gorenjskem v obdobju 2001 do 2004. Rezultati anket kažejo, da je večini kmetov znan pomen stročnic pri ohranjanju in izboljšanju rodovitnosti tal, kljub temu pa stročnicam pri sestavi njivskih kolobarjev ne namenjajo pozornosti zaradi nepoznavanja vrst in tehnologije pridelave na njivi ter neznanja pri uporabi zrnja in zelinja za prehrano ljudi in živali. S preučitvijo sestave štiriletnih njivskih kolobarjev na treh ekoloških kmetijah je bilo ugotovljeno, da je delež okopavin v kolobarju na kmetiji A 48 %, na kmetiji B 57 % in na kmetiji C 41 %, kar v primerjavi z norfolkškim kolobarjem presega ustrezen 25-odstotni delež okopavin, nasprotno pa je delež žit v kolobarjih teh kmetij veliko manjši od  ustreznih 50 %  in sicer na kmetiji C jih je 34 %, na kmetiji A 29 %, na kmetiji B pa komaj 18 %; od stročnic so v njivskem kolobarju le detelje v mešanicah s travami (kmetija A 23 %, kmetija B 25 %, kmetija C 41 %), kar pomeni, da imata kmetiji A in B v kolobarju pomembno manj stročnic, ki bi morale v čistem posevku pokrivati 25 % zemljišč. V predlogu izboljšanih kolobarjev je večji delež žit in manjši delež okopavin ter setev stročnic v smeri čistih posevkov detelj in debelo zrnatih stročnic za krmo živali v čistih posevkih (grah, soja) in v mešanih posevkih (ovsiga), ekološki kmetje pa bi morali razmisliti tudi o širjenju debelo zrnatih stročnic za prehrano ljudi iz gredic na njive.

 ABSTRACT

 LEGUMES  IN CROP ROTATION OF SLOVENIAN ORGANIC FARMS

 Analysis of legumes, included in the crop rotation of Slovenian organic farms was based on the questionnaire, sent to the farmers on 30 organic farms in the end of 2002 and 2004 and on the study of crop rotation composition on three organic farms in Gorenjska region in the period from 2001 to 2004. The results of the study showed that most farmers were well acquainted with the importance of legumes in keeping and improving the soil fertility, although they still have not put enough attention to the inclusion of the legumes into the crop rotation due to lack of knowledge on different types of legumes and field production technologies and due to unawareness of the grain and herbage usage in human consumption and animal nutrition. With the study of four-year crop rotation composition on three organic farms it was ascertained that the share of root crops in the crop rotation on farm A was 48 %, on farm B 57 % and on farm C 41 %. These figures exceeded the suitable 25 % share of root crops in Norfolk's crop rotation. On the contrary, the share of cereals in crop rotation was much lower than the most suitable one of 50 % - on farm C 34 %, on farm A 29 % and on farm B only 18 %. Among legume crops, included in the crop rotation, there was only the clover mixed with grass (farm A 23 %, farm B 25 %, farm C 41 %). It has been shown that, especially in farms A and B, the share of legumes in the crop rotation was significantly lower than the recommended one (25 % of the land measured as the single crop). In our proposal for the improved crop rotation a bigger share of cereals and smaller share of root crops was anticipated as well as the changes in the legumes’ structure, directing the clover sowing in unmixed crops and grain legumes for animal nutrition in pure crops (pea, soya) and/or in mixed crops. Organic farmers should also consider the spread of grain legumes for human consumption from garden beds level to the fields.

 

The response of sunflower to acute disturbance in water availability

 Mateja GERM, Olga URBANC BERČIČ, Darja KOCJAN AČKO

 ABSTRACT

 The influence of disturbance in water availability to electron flow in photosystem II was studied in five cultivars of sunflower. The results showed unaffected optimal quantum yield of photosystem II in the plants exposed to limited water supply, indicating the short-term tolerance of photosynthetic processes to acute water deficiency. Effective quantum yield of photosystem II was affected by interruption of water flow through the plants. Cultivar Labud exhibited the greatest sensitivity to water deficiency.

 IZVLEČEK

 ODZIV SONČNIC NA AKUTNO POMANJKANJE VODE

 Pri petih kultivarjih sončnic smo preučevali vpliv omejene preskrbe z vodo na pretok elektronov v fotosistemu II. Prekinitev vodnega toka skozi rastlino ni vplivala na optimalno fotokemično učinkovitost fotosistema II, kar kaže na odpornost procesa fotosinteze na akutno zmanjšano preskrbljenost rastlin z vodo. Dejanska fotokemična učinkovitost fotosistema II se ob akutni motnji preskrbe z vodo zmanjša. Odziv kultivarja Labud kaže največjo občutljivost.

 

Influence of foliar-applied phosphorus and potassium on photosynthesis and transpiration of ‘Golden Delicious’ apple leaves (Malus domestica Borkh.)

 

Robert Veberič, Dominik Vodnik, Franci Štampar

 Abstract

The influence of foliar-applied phosphorus (P) and potassium (K) on leaf photosynthesis, transpiration and water use efficiency during the season was studied in Malus domestica ‘Golden Delicious’. The research was carried out on 14-year-old trees on M9 rootstocks. Trees were either sprayed with PK (Hascon M 10 AD), P (Radicon) or K fertiliser (Krad) or left unsprayed (control). PK spraying improved leaf potassium content and postponed the seasonal decrease in leaf potassium concentration. In other treatments, on the other hand, fertilizers were less effective in terms of leaf nutrient concentration enhancement. In general P, and to a lesser extent PK, spraying resulted in reduced leaf photosynthesis and transpiration to the K and control treatments. High leaf photosynthetic and transpiration rates were measured in the control. Trees sprayed with PK showed the highest water use efficiency during the summer period, which could be a benefit in response to water stress, frequently experienced under given climate.

 Izvleček

 Vpliv foliarno nanešenega fosforja in kalija na fotosintezo in transpiracijo listov jablane (Malus domestica Borkh.) ‘ZLATI DELIŠES’

 Proučevali smo vpliv foliarno dodanega fosforja (P) in kalija (K) na fotosintezo, transpiracijo in učinkovitost izrabe vode listov jablane (Malus domestica Borkh.) ‘Zlati delišes’. Poskus je bil zasnovan na 14 let starih drevesih cepljenih na podlago M9. Drevesa smo poškropili s PK (Hascon M 10 AD), P (Radicon), K gnojilom (Krad) in jih primerjali z neškropljenimi drevesi (kontrola). Škropljenje s PK je vplivalo predvsem na večjo vsebnost kalija v listih ter zmanjšalo sezonski padec v vsebnosti tega elementa. Druga obravnavanja so se izkazala kot manj učinkovita z vidika povečanja vsebnosti elementov v listih. V primerjavi s K škropljenimi drevesi in kontrolnimi drevesi, je škropljenje s P in nekoliko manj s PK zmanjšalo fotosintezo in transpiracijo listov. Drevesa škropljena s PK so kazala v poletnem času največjo vrednost parametra učinkovitosti izrabe vode, kar bi lahko bilo pomembno z vidika zmanjševanja sušnega stresa, s katerim se pogosto srečamo v naših krajih v tem obdobju.