Primerjava lastnosti obložene cementno-iverne plošče in površinsko obdelane furnirne plošče

In this study, we produced two types of claddings, representing the element of the ventilated façade. The first façade cladding was a cement-bonded particleboard, surfaced with a low-pressure laminate, while the second was a waterproof plywood board, coated with a stain-coating system. Both types of façade claddings were exposed to processes of artificial accelerated aging and temperature cycling tests, as well as to biotic factors, in order to simulate the conditions in real use. Changes in climatic conditions and other factors of the performed tests had a larger influence on the behaviour and properties of the surface finished plywood board. Both types of composites were not susceptible to infection with wood decay and blue-stain fungi. According to the results of the research, both types of claddings are suitable for the intended use as the outer element of a ventilated façade

Comparison of properties of surfaced cement-bonded particleboard and surface finished plywood

V raziskavi smo izdelali dve vrsti oblog, namenjeni za zunanji sloj prezračevane fasade. Prvo fasadno oblogo je predstavljala cementno-iverna plošča, obložena z nizkotlačnim laminatom za oblaganje, drugo pa vlagoodporna furnirna plošča, premazana z lazurnim premaznim sistemom. Obe vrsti fasadnih oblog smo izpostavili postopku umetnega pospešenega staranja in temperaturnega obremenjevanja ter biotskim dejavnikom, s čimer smo simulirali pogoje realne uporabe. Spremembe klimatskih pogojev in ostali dejavniki opravljenih preskusov so vplivali bolj na obnašanje in lastnosti površinsko obdelane furnirne plošče. Obe vrsti kompozitov nista bili dovzetni za okužbo z glivami modrivkami in razkrojevalkami. Glede na rezultate raziskave sta tako obe vrsti oblog primerni za uporabo v gradbeništvu kot zunanji element prezračevane fasade.In this study, we produced two types of claddings, representing the element of the ventilated façade. The first façade cladding was a cement-bonded particleboard, surfaced with a low-pressure laminate, while the second was a waterproof plywood board, coated with a stain-coating system. Both types of façade claddings were exposed to processes of artificial accelerated aging and temperature cycling tests, as well as to biotic factors, in order to simulate the conditions in real use. Changes in climatic conditions and other factors of the performed tests had a larger influence on the behaviour and properties of the surface finished plywood board. Both types of composites were not susceptible to infection with wood decay and blue-stain fungi. According to the results of the research, both types of claddings are suitable for the intended use as the outer element of a ventilated façade

Endophytic fungi as biological control agents and their indirect effects on plants

Uporaba entomopatogenih gliv predstavlja enega temeljnih ukrepov nekemičnega varstva rastlin pred škodljivci. Poleg patogenosti za členonožce imajo te glive tudi druge lastnosti, zaradi katerih so širše uporabne v biotičnem varstvu rastlin. V rastlinah živijo kot endofiti in lahko delujejo zaviralno tudi na različne povzročitelje rastlinskih bolezni. Naseljujejo rizosfero številnih rastlin v naravnih in kmetijskih ekosistemih ter delujejo spodbujevalno na njihovo rast in razvoj. Te v zadnjem času dognane ekološke funkcije še niso podrobneje raziskane, vendar kljub temu nakazujejo na širši potencial uporabe entomopatogenih endofitnih gliv pri pridelavi rastlin, ne le kot sredstev za biotično zatiranje škodljivcev, pač pa tudi kot mikofungicidov in sredstev za krepitev rasti in razvoja (biostimulantov). Za umestitev uporabe entomopatogenih endofitnih gliv v vsakdanjo kmetijsko prakso je potrebno pri razvoju komercialnih pripravkov upoštevati praktičnost uporabe in preučiti tehnike nanosa entomopatogenih endofitnih gliv, ki omogočajo uspešno kolonizacijo rastlin

Insecticidal proteins and their potential use for Colorado potato beetle (Leptinotarsa decemlineata [Say, 1824]) control

Rastline se na napad škodljivcev odzovejo med drugim tudi s tvorbo specifičnih proteinov z insekticidnim delovanjem. Proteine s toksičnim delovanjem na žuželke so odkrili tudi v številnih drugih organizmih, predvsem glivah in bakterijah. Zaradi omenjene biološke funkcije insekticidni proteini predstavljajo pomemben potencial v razvoju okolju prijaznih metod varstva rastlin. Poznavanje mehanizmov delovanja insekticidnih proteinov in identifikacija genov za njihovo sintezo omogočata žlahtnjenje transgenih sort rastlin odpornih na škodljive žuželke ter razvoj bioinsekticidnih učinkovin. Koloradski hrošč je pomemben škodljivec krompirja, zato je preučevanje tovrstnih načinov varstva rastlin ključno za razvoj trajnostnih strategij integriranega varstva krompirja. V prispevku povzemamo lastnosti nekaterih skupin insekticidno delujočih proteinov in njihovih mehanizmov delovanja ter primerov preučevanja njihove uporabe za zatiranje koloradskega hrošča

Evaluation of the field efficacy of Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) and synthetic insecticides for the control of western corn rootworm larvae

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera, Chrysomelidae), is an important insect pest of maize in North America and Central and Eastern Europe. In Central Europe, the larvae emerge in May and its three instars feed intensively on maize roots in June, causing plant lodging that leads to a loss of economic yield. A three-year field experiment (2016–2018) was conducted to compare the effectiveness i) of soil-applied granular insecticide based on the active ingredient tefluthrin, ii) of maize seeds dressed with thiacloprid, and iii) entomopathogenic nematodes Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae, product Dianem) against WCR larvae. An additional treatment with alcohol ethoxylate (i.e., soil conditioner) mixed with entomopathogenic nematodes was performed in 2017 and 2018 to check for any increase of entomopathogenic nematodes’ effectiveness. Field tests were carried out in two fields infested naturally with a WCR pest population, one in Bučečovci (Eastern Slovenia) and the other in Šmartno pri Cerkljah (northern Slovenia), exhibiting dissimilar pedo-climatic conditions and soil pest densities. The treatments were performed in five replicates per experiment in each year. The efficacy of the treatments was very similar at both locations, despite the approximately five-fold lower WCR soil pest densities in northern than in eastern Slovenia, as well as being constant over time. The largest number of WCR beetles was observed in the negative control, followed by that of beetles subjected to thiacloprid treatment (insignificant decrease taking into account the entire three-year dataset). Treatments with tefluthrin (44.1 ± 11.7%), H. bacteriophora (46.2 ± 7.4%), and H. bacteriophora + alcohol ethoxylate (49.2 ± 1.8%) significantly decreased the numbers of emerging beetles. Treatments of thiacloprid, H. bacteriophora, and H. bacteriophora + alcohol ethoxylate additionally led to significantly increased maize plant weights. Furthermore, entomopathogenic nematodes were able to persist in maize fields for almost five months at both experimental locations in silty and sandy loam soils. It was concluded that the control of WCR larvae in maize using the entomopathogenic nematode H. bacteriophora is as effective as a tefluthrin treatment, and could thus offer a sustainable Diabrotica v. virgifera biological control management option in Europe

Effectiveness of different control measures against western corn rootworm larvae Diabrotica virgifera virgifera LeConte, 1868

The Western Corn Rootworm (WCR), Diabrotica virgifera virgifera LeConte, 1868, [Coleoptera, Chrysomelidae], whose larvae cause damage to maize roots, is an important economic insect pest in America and Europe. Its larvae are usually controlled by granular soil insecticides or insecticide-treated seeds. Biological control options, such as entomopathogenic nematodes (EPN) have played an important role as an alternative for synthetic chemical insecticides. Therefore, for the WCR larvae control we compared the effectiveness of inundative biological control on the basis of EPN Heterorhabditis bacteriophora Poinar, 1976 (Rhabditida: Heterorhabditidae); (commercial product Dianem®) and the conventional insecticides Force 1.5 g (active substance tefluthrin) from the group of synthetic pyrethriods and Sonido (active substance thiacloprid) from the group of neonicotinoids. Field experiments were carried out at geographically different locations under different population pressure of the insect pest in a), Bučečovci (Prlekija; Eastern Slovenia) and b), Šmartno (Gorenjska: northern Slovenia). The differences between the treatments were very similar at both locations; although the population of WCR in Gorenjska was approximately 5-fold lower than in Prlekija. The highest number of WCR beetles was caught in the negative control, followed by the product Sonido, Force and Dianem®, in decreasing order. Statistical analysis showed that only in the treatment where EPN were used, significantly less WCR was caught than in the control. The results of the WCR larvae control in maize using Heterorhabditis bacteriophora are comparable to published literature. However, the weather conditions in the 2016 trial were very favorable for the development and survival of EPN in the soil.</p