This paper provides the first detailed presentation of research and professional activities in the field of biological control in Slovenia during the period of 1990–2020. It presents information on ...the important pioneering role of Prof. Dr. Lea Milevoj in biological control research in Slovenia, especially in regard to the inventorying and laboratory rearing of indigenous beneficial organisms, evaluation of the influence of food type on the feeding behaviour of beneficial organisms, participation in the first introduction of a natural enemy within the context of classical biological control in Slovenia, preparation of rules on the biological control of plant pests and publication of the first Slovenian monograph on biological control. The paper also describes the activities of Slovenian researchers in regard to entomopathogenic nematodes, especially related to the assessment of their presence and efficiency in suppressing harmful insects and the identification of indigenous parasitic nematodes associated with economically harmful slugs. The paper also notes some applicative and basic research projects pertaining to parasitoids, especially in terms of their function as natural enemies of aphids, and in regard to predators of harmful insects and mites, especially predatory mites. The main goal of these activities is to implement the use of as many natural enemies as possible in food and ornamental plant production systems to replace the use of plant protection products.
The main purpose of the study was to examine the potential of crops, such as soybeans (Glycine max), sunflowers (Helianthus annuus), alfalfa (Medicago sativa), and sorghum (Sorghum bicolor), as trap ...crops for Halyomorpha halys. We monitored the abundance and seasonal dynamics of H. halys (egg clusters, larvae, and adults) on a selected number of various crops at 10-day intervals. The experiment was performed in two different regions of Slovenia (western and central) and in two different years (2021, 2022). The results varied depending on the location and the year. In the first experiment, data from the entire year showed that sorghum was the most attractive for H. halys adults (1.56 ± 0.12), followed by sunflowers (0.61 ± 0.05), soybeans (0.37 ± 0.03) and alfalfa (0.41 ± 0.21). In the second experiment, the abundance numbers of the pest were significantly lower compared to those of the first experiment sorghum and soybeans (0.003 3 ± 0.002), sunflowers (0.000 3 ± 0.000 3). In both cases, the abundance numbers increased when all the crops entered the fruit development stage (BBCH 70+). Overall, the lower density of the H. halys population and the experimental design could also be some of the factors for such a low incidence of stink bugs in the central region of the country. More research will be needed to further develop effective control methods for this invasive pest.
For 2 years (2019–2020), a field experiment to test the activities of different fertilisation schemes on the yield, colour and health status of five different grass mixtures for football pitches was ...conducted. Two grass mixtures were composed of different varieties of perennial ryegrass, one mixture was composed of varieties of perennial ryegrass and Kentucky bluegrass, one mixture consisted of the species Lolium perenne, Festuca rubra, Festuca arundinacea and Poa pratensis, and the seeds of only one variety of perennial ryegrass were sowed in one plot. Three different fertilisation schemes were included in the experiment. The first scheme (A) contained an inorganic fertiliser with added soil improvers, the second scheme (B) included an organic fertiliser with added soil improvers and the third scheme (C) was composed of an inorganic fertiliser. According to this study, the grass yield largely depends on the soil temperature, amount of precipitation and soil water content, and the occurrence of the fungus Laetisaria fuciformis is influenced by the fertilisation scheme, as the % infection with the fungus was highest when organic fertilisers with low % nitrogen was used. The selection of fertilisers is seen as an important factor for the turfgrass colour.
V preglednem članku se osredotočamo na alternativni pristop varstva krompirja (Solanum tuberosum) pred koloradskim hroščem (Leptinotarsa decemlineata), ki pri nas in v svetu velja za najpomembnejšega ...škodljivca te pomembne poljščine. V prispevku predstavljamo uporabo različnih inertnih prahov za zatiranje tega škodljivca. Osredotočili smo se na kategorizacijo prahov, predstavitev posameznih skupin inertnih prahov in opis ene ali več snovi, ki pripadajo specifični skupini. Poleg splošne predstavitve načinov delovanja posameznih prašiv navajamo tudi praktične zglede uporabe prašiv proti koloradskemu hrošču, s čimer želimo predstaviti potencial različnih prašiv za uporabo v praksi. Ugotavljamo, da veljata lesni pepel in diatomejska zemlja za bolj perspektivna inertna prahova pri zatiranju škodljivih žuželk. Lesni pepel učinkovito deluje proti ličinkam ter v manjši meri tudi na odrasle osebke, diatomejska zemlja pa prav tako vpliva na zmanjšanje številčnosti koloradskega hrošča na krompirju. Ostala inertna prašiva so v strokovni literaturi izpostavljena kot manj učinkovita oz. sploh še niso bila preizkušena ali uporabljena proti temu škodljivcu. Za dokončno določitev učinkovitosti prašiv bodo potrebne nadaljnje raziskave, tako v laboratorijskih razmerah kot na prostem.
In 2017, we conducted a field experiment to test the influence of a mixture of two plant growth-promoting bacteria (Pseudomonas fluorescens and Azospirillum brasilense) on the yield of three potato ...varieties. In addition, the influence of the mixture on potato susceptibility to infection by the pseudofungus Phytophthora infestans and fungus Alternaria solani and to attacks by the Colorado potato beetle (Leptinotarsa decemlineata) was investigated. It was the first experiment of its kind in Europe. In the unusually hot and dry year, a positive influence on the yield (17%-31%) was found in all three varieties when the tubers were soaked in the bacterial mixture prior to sowing. We observed no significant differences in potato resilience/susceptibility to harmful organisms among the different treatments (soaked tubers, sprayed tubers, untreated tubers); however, there were significant differences in the productivity between the tuber varieties. The results of our research indicate the bacterial mixture used in this study has a high potential to support satisfactory potato yields under dry conditions and under low levels of infection by foliar fungal diseases and attacks by foliar insects.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In 2020, a greenhouse experiment was conducted to investigate the suppression of annual bluegrass (
), which is a difficult weed to manage in cool-season in turfgrass mixtures on football pitches. ...The efficacy of prohexadione calcium (Pc), ethephon (Eth) and
against
,
and
was tested, as the latter two most commonly occur in turfgrass mixtures on football pitches. Mesotrione (Mes) was used as a positive control, and nontreated grass was used as a negative control. Only a single grass species was sown in each pot. Treatments were randomly distributed for two experiments conducted separately: first – unmown grass before the beginning of spraying and second – grass mowed before the beginning of spraying. In both experiments, plant height and the number of tillers were measured/counted several times during the growing season. In both experiments, grasses were sprayed six times with Pc, Eth and
, while Mes was applied twice. Based on the performed study, the efficacy of the tested products is connected to grass species and whether the grass was mowed/cut before spraying. It has been detected in the present study that spraying with Pc could reduce the height of annual bluegrass, while spraying with
has reduced the number of tillers. Spraying was more effective on grasses that were mowed/cut before the beginning of spraying. Mes should cause severe damage to annual bluegrass but without confirmation in this study. Results of this study have indicated that the application of Pc and
can inhibit the spread of annual bluegrass in football pitches; however, testing their effectiveness against
under field conditions should be performed as well.
Laboratory tests were carried out to evaluate the insecticidal efficacy of different natural inert dusts (diatomaceous earth, wood ash, quartz sand) and the leaf powder of Azadirachta indica A. Juss. ...against granary weevil (Sitophilus granarius L.) adults. The efficacy of the substances was tested individually and in combination with each other. The substances were applied at different concentrations, and bioassays were carried out at four different temperatures (20, 25, 30 and 35°C) and two different relative humidity (RH) levels (55% and 75%). The adult mortality was recorded after the 7th, 14th and 21st days of exposure. The progeny production of individuals exposed to different combinations was also assessed. Wood ash proved to be the most efficient inert dust in our research. We detected 100% mortality in the treatment exposed to a higher concentration (5 w%) of wood ash at 35°C and 55% RH after 7 days of exposure. A lower RH level had also a negative impact on the progeny production. We can conclude that wood ash can be efficient in controlling granary weevil adults as a single substance or in combination with other substances. Further surveys should focus on the impact of the wood ash dose rates. Due to the high percentage of area covered with forest in some European countries, the main ingredient is present locally, but additional surveys are needed to help improve the practical use of wood ash.
ABSTRACTThis paper addresses yield loss due to red deer (Cervus elaphus) grazing on permanent grasslands on three organic farms in SE Slovenia over two consecutive years. Deer graze on permanent ...grasslands throughout the year, but the resulting crop loss varies during the growing season. Accounting for three mowings, the quantitative yield loss due to deer grazing totalled 48–52%, or 3.9–4.3 t/ha. Deer had the highest consumption capacity in the spring (first mowing: yield loss of 1.7–1.9 t of air-dried hay/ha), and towards the end of the growing season, consumption decreased (third mowing: loss of 0.9 t/ha). A floristic inventory indicated low species diversity and production in permanent grasslands in SE Slovenia. The crude protein content in unprotected plots was generally greater than that in protected plots, but due to a large quantitative yield loss, the yield of crude protein and net energy for lactation on heavily grazed land were much lower than those on protected land in all mowings. The average additional cost per unit of heavily grazed area ranged from 182 to 344 EUR/ha, and the differences are the result of the different intensities of game grazing in individual locations and grassland production capacities.
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In this paper, we present five species of owlet moths (Noctuidae), whose greater abundance was found in Slovenia in the period 2019-2022 as part of research and expert work in the field of plant ...protection. The greatest economic importance is attributed to the tomato looper (Chrysodeixis chalcites), which two years after its first strong appearance on the Slovenian coastal area is already causing major problems for tomato growers. We did not confirm the harmfulness of the caterpillars on cultivated plants for the silver-Y moth (Autographa gamma), the adult males of which are caught in large numbers using pheromone traps in central Slovenia, and the less numerous beet armyworm (Spodoptera exigua). We can confirm the same for the shark moth (Cucullia umbratica), whose adult males are caught in pheromone traps of the EU quarantine pest Spodoptera frugiperda and the copper underwing (Amphipyra pyramidea), for which we suggest the Slovenian name ‘bakreni podkrilec’, which appeared in, on or in the immediate vicinity of the pheromone traps of the spongy moth (Lymantria dispar) in the oak-hornbeam forest in Prekmurje.
Lymantria dispar, a well-known defoliating pest species, also presents a health challenge due to the allergenic potential of its hairs, making it interesting to study from various perspectives. ...As chemical control methods decline in popularity, the search for effective natural enemies of this pest, such as predators, parasites and parasitoids, are expanding. On this occasion, we report the discovery of the primary parasitoid Glyptapanteles liparidis and the secondary parasitoid Gelis areator for the fauna of Slovenia. Illustrations and a short biology are given for both species.
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