Weed infestation is a major cause of the poor yield of soybeans (Glycine max (L.) Merr.); therefore, proper weed management represents one of the most important and expensive steps in soybean ...production. Field experiments were established in northeastern parts of Croatia, in the Vukovar-Syrmia county from 2014 to 2016, arranged in a split-plot design with four replications. Two different studies were conducted: the first study was to determine the weed interference, weed biomass accumulation, yield, and yield components of soybeans growing in three different rows spacing (25, 50, and 70 cm), and the second study aimed to simulate a risk analysis by building models of probabilities for generating profit as a result of weed control. The weed community in soybean during the study period comprised 34 dicot and grass species of a varied perennation. Compositional differences in the weed community tended to be affected most by the year (humid–arid environment), followed by row spacing. There were no differences in the weed biomass accumulation with a reduction in row spacing from 70 to 50 and 25 cm. The dominant weed species Amaranthus retroflexus, Ambrosia artemisiifolia, Chenopodium album, Datura stramonium, Setaria viridis, and Sorghum halepense formed the main biomass and were spread over all row spacings. There was a significant influence of row spacing, the duration of weed interference, and year on soybean yield and yield components. Weed infestation until the second trifoliate (V2) stage had no detrimental effect on soybean yield, regardless of the row spacing. The number of pods per plant significantly decreased at the same V2 stage in 25 and 50-cm rows, but in 70-cm soybean rows, this process started later, at four unfolded trifoliate leaves (V4 stage). A 1000 kernel weight was less sensitive to weed infestation and was significantly decreased at full flowering (R2 stage) in 25 and 70 cm rows, while it already decreased at the V4 stage in 50 cm rows. The probability distribution of achieving a profit showed the best results for soybeans growing in 70 cm rows, with preemergence herbicide application and two inter-row cultivation.
Field studies were conducted in the northeastern part of the Republic of Croatia to determine the influence of the critical period of weed interference on sunflower (Helianthus annuus) yield, yield ...components, and oil content. For this purpose, different durations of competition were established, allowing weeds to infest the crop for increasing periods of time after planting or maintaining plots weed-free for increasing periods of time after planting. The beginning and the end of the critical period of weed control (CPWC), based on a 5% and 10% loss of sunflower yield, were determined by fitting the four-parameter log-logistic equations to the relative seed yield. The total weed biomass increased progressively in relation to the increase in the competition. The beginning of the CPWC period, based on a 5% acceptable yield loss, ranged from 141 to 234 growing degree days (GDD), which corresponded to the two-to-four true leaf development stage (the V2–V4 growth stages) across both sites and years. The crop had to be kept weed-free until a period when sunflower inflorescence began to open and flower (the R4–R5 growth stage) or from 1365 to 1932 GDD. The sunflower yield and yield components varied between the years and among locations. An increasing duration of weed interference negatively affected crop height, head diameter, and 1000-kernel weight, but not seed oil content.
Field margins are pollinator-friendly habitats and important refuges for many pollinators. As a valuable food resource throughout the vegetation season, not just when crop species are in flower, ...field margins need to be protect or restore in areas of intensive farming. This paper examines the floristic and functional structure of weed communities on field margins in the northeastern part of the Republic of Croatia. A phytocoenological survey was conducted during the summer period of 2017 and 2018. A total of 32 field margins was analyzed for species richness, abundance and their role for entomofauna. Floristically rich field margins consist of 72,6% plant species beneficial to pollinators. Foraging period can be stretching throughout the year, but stabile and high flowering period is from May to end of September. Among highest ranked honeybee plants, several invasive species with significant relative abundance are: Solidago gigantea, Asclepias syriaca and Amorpha fruticosa who pose a serious threat to plant biodiversity. Positive role of vegetation from field margins was not valuable for pollinators only, but they also serve as supply the substrates that provide a shelter and nesting sites.
A vegetation survey in northeastern Croatia explored the influence of intensive arable farming on the weed community in relation to the crop edge and adjacent field margin. A total of 141 vascular ...plants were recorded, and significant differences among the species appear in the field margins (134) as compared to the crop edges (109) and middle of the fields (49). Native plants predominated (83.7%), but among non-natives, the most abundant were Ambrosia artemisiifolia L., Abutilon theoprasti Med. and Veronica persica Poir., with the highest cover values inside the cropped areas, particularly during spring sowing of row crops. The most diverse (having significantly higher Evenness and Shannon?s diversity index) was the community from the field margin, followed by the weed community that developed on the crop edges. Three distribution patterns were observed: weeds typically limited to the crop area, weeds limited to the non-crop area and weeds with some ability to spread from the field margins. Major variations in species composition were identified according to sowing season and crop type. Wind dispersal annuals with light- and nitrogen-demands were associated with disturbed, tilled habitats, while perennials with higher requirements for moisture and other than a wind mode of dispersal, were associated with the field margins.
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Abstract This paper analyses the floristic biodiversity of weed communities in the arable lands of the Istrian peninsula during a twelve year period (2005–2017). A total of 50 fields were surveyed ...for each sampling time using the seven-degree Braun-Blanquet cover abundance scale in the following agricultural categories: a) permanent crops (vineyards/olive groves), b) alfalfa fields, c) cereals, d) row crops and e) ruderal areas. The taxonomic identification was performed during the full development of vegetation, for cereals in June and July, and for the rest – in August and September. A total of 175 weed species were determined during both study periods with Asteraceae and Poaceae families as the most abundant. Altogether, therophytes were dominant in both surveys, followed by hemycryptophytes and geophytes. Variations in species composition were visible in both study periods (2005 and 2017) as well as in the selected habitat types. Exclusive species were found in addition to those that were common for both surveys. Changes in species composition between 2005 and 2017 referred to the difference in row spacing in earlier period, and ruderal vs. agricultural habitats in the recent survey. The differences in phenological traits between the past and present surveys were greatest for germination season in permanent crops and row crops, flowering start for permanent crops, flowering period for ruderal area and weed height for permanent crops. Significant differences between the past and present survey for other plant traits did not occur.
Strane, a posebno invazivne vrste često imaju negativan učinak na biološku raznolikost, ekonomiju, pa i ljudsko zdravlje. One su sposobne
proizvoditi produktivno potomstvo i posjeduju potencijal ...širenja na značajnim površinama. Stoga je širenje invazivnih vrsta jedno od najvećih problema u zaštiti prirode. Praćenje rasprostranjenosti i procjena rizika invazivne vaskularne flore Požeške kotline vršeno je tijekom ljetnih mjeseci od 2017. do 2019. godine putem kombinirane procjene brojnosti i pokrovnosti. Istraživanjima je utvrđeno ukupno 34 invazivne svojte vaskularne flore kojima je pridružena porodica, životni
oblik, geografsko porijeklo te je procjenjena faza procesa invazije. Za
analizu povezanosti između nadmorske visine i pokrovnih vrijednosti invazivne flore Požeške kotline, primjenjena je multivarijantna statistička tehnika - CCA analiza. Najbrojnije vrstama su porodice Asteraceae i Poaceae. Analiza životnih oblika izdvojila je dominaciju terofita, ali i prisutnost hemikriptofita, fanerofita, geofita i hidrofita. Po porijeklu invazivne biljke pronađene u Požeškoj kotlini dolaze prvenstveno sa američkog područja, posebice Sjeverne Amerike, a zatim slijede one iz Azije i Afrike. Većina zabilježene invazivne flore nalazi se u stadiju ekspanzije tj. kolonizacije. Dobar dio je već naturaliziran, a dio je u fazi introdukcije. Nizinska područja do 200 m nadmorske visine pogoduju najvećem broju invazivnih biljaka. Samo manji broj biljnih vrsta je pozitivno koreliran s brežuljkastim područjima gdje se ističu vrste Phytolacca americana L. i Ailanthus altissima (Mill.) Swingle. Najviše zahvaćeni invazijom su ruderalna i poljoprivredna staništa.
Non native, and especially invasive plants, often have a negative impact on biodiversity, economy, and even on human health. They have rapid reproduction potential and are capable for dispersal over significat areal. They have a negative impact on biological diversity, economy and even on human health. Therefore, the spread of invasive plant species is consider as one of the biggest problems in nature protection. Research on prevalence and risk assesment of invasive vascular flora in Požega valley were conducted during the summer months from 2017 to 2019 using the Br. –Bl. (1964.) cover/abundance method. A thirty four invasive species were detected during the study period. Analysis according to family affiliation, life form, geographic origin and invasion stage were made. Multivariate statistical technique –CCA were use to analyse relation between elevation and cover values of invasive flora of Požega valley. The most numerous families are Asteraceae and Poaceae. Life-form analysis showed the predominance of therophytes, but also presence of hemicryptophytes, phanaerophytes, geophites and hydrophyte. Regaridng origin, majority of invasive alien species come from American continent, particularly from North America, followed by those from Asia and Africa. Most of them (47%) are in the stage of invasion i.e. colonisation. Many of them are already naturalised, and in invasion phase. Lowlands (elevation up to 200 m) are favorable sites for most of the invasive plants, and just small amount of them, like Phytolacca americana L. and Ailanthus altissima (Mill.) Swingle are positively correlated with the hilly areas. The most affected by the invasion are ruderal and agricultural habitats.
Field study tested weed control efficacy, crop yield and economic return using various weed management strategies in sunflower growing with different population density. Treatments included four ...rates of PRE emergence application of S-metolachlor + fluchloridon and one POST emergence application of flumioxazin + quizalofop-pethyl. PRE-em application (1.4 + 2.4 and 1.2 + 2.0) provided at the higher crop densities (70 000) best weed control. However, PRE- em treatments with lower doses (0.8 + 1.6 and 1.0 + 1.8) and POST- em application did not maintain acceptable control of dominant weeds. Grain yield increased with the crop density, but did not statistically differ between applied herbicide treatments. Finally, the implication of this study demonstrated that sole application of tested herbicide treatments at higher crop sowing density (60 000 and 70 000) was found to be economically the best alternative strategy for reducing weed infestation and achieving a better yield.
The study investigated the insecticidal efficacy of six Croatian inert dusts (D-01, JU-1, MA-4, MR-10, OP-4 and PD-1) and diatomaceous earth Celatom Mn-51® against red flour beetle Tribolium ...castaneum Herbst on wheat. The influence of mentioned dusts on the offspring development has also been investigated. The experiment was carried out in laboratory conditions on insects aged 7-21 days. Doses of 600 and 700 mg were tested for JU-1, MR-10, OP-4 and PD-1 and 300 and 400 mg for D-01, MA-4 and Celatom Mn-51® alongside previously mentioned doses (600 and 700 mg ). The mortality rate of red flour beetle was determined on the 7th and 14th day of exposure and progeny was determined by number of developed adults. Regarding the insecticidal efficacy on T. castaneum the tested inert dusts can be divided into three groups: very effective dusts (D-01 ( = 600 mg ), MA-4 ( = 500 mg ), medium-effective dusts (JU-1 and PD-1) and low-efficient dusts (OP-4 and MR-10). Based on the obtained results it can be concluded that there are some resources of inert dusts with high insecticidal potential in the Republic of Croatia.
U radu je istražena insekticidna učinkovitost šest hrvatskih inertnih prašiva (D-01, JU-1, MA-4, MR-10,OP-4 i PD-1) i dijatomejske zemlje Celatom Mn-51® u suzbijanju kestenjastog brašnara Triboliumcastaneum Herbst na pšenici. Istraživan je i utjecaj navedenih prašina na razvoj potomstva. Pokusje proveden u laboratorijskim uvjetima s kukcima starosti 7-21 dan. Za tretmane JU-1, MR-10,OP-4 i PD-1 korištene su doze od 600 i 700 mg kg-1 a za tretmane D-01, MA-4 i Celatom Mn-51®, uzP. Lucić et al.: Efficacy of six Croatian inert dusts and diatomaceous earth Celatom Mn-51® against...Zbornik Veleučilišta u Rijeci, Vol. 12 (2024), No.1, pp. 441-453453navedene, korištene su i doze od 300 i 400 mg kg-1. Mortalitet kestenjastog brašnara utvrđen je nakon7. i 14. dana ekspozicije, a potomstvo je utvrđeno brojem razvijenih odraslih jedinki. S obzirom nainsekticidnu učinkovitost na T. castaneum, testirana inertna prašiva možemo podijeliti u tri skupine:vrlo učinkovita prašiva (D-01 (LD90 = 600 mg kg-1), MA-4 (LD90 = 500 mg kg-1)), srednje učinkovitaprašiva (JU-1 i PD-1) i nisko učinkovita prašiva (OP-4 i MR-10). Na temelju dobivenih rezultata može sezaključiti da u Republici Hrvatskoj postoje izvori inertnih prašina s visokim insekticidnim potencijalom.
Na blago valovitim istočnim obroncima Psunja razvijeni su suhi brdski travnjaci, koji predstavljaju jedan od najugroženijih oblika vegetacije,
a bili su predmet ovog istraživanja. Teren je blago ...nagnut prema jugoistoku, južne je ekspozicije, nadmorska visina oko 400 m. Cilj istraživanja bio je utvrditi brojnost i raznolikost samonikle vaskularne
flore travnjaka na području Rudine. Floristička istraživanja vršena su 2003., 2008., 2016. i 2017. godine. Na površini od oko 2500 m2 popisane su i determinirane biljne svojte, određena njihova pripadnost porodicama, flornim elementima i životnim oblicima. Zabilježeno je 186 biljnih svojti vaskularne flore unutar 46 porodica i 134 roda. Izvršena je taksonomska, ekološka i fitogeološka analiza. Taksonomska analiza ukazuje da golosjemenjača ima 2 vrste (1,08 %), dvosupnica 155 vrsta (83,33 %), a jednosupnica 29 vrsta (15,59 %). Analiza životnih oblika pokazuje da su najviše zastupljeni hemikriptofiti sa 113 vrsta (60,75 %)
i terofiti s 29 vrsta (15,59 %). U fitogeografskoj analizi dominiraju biljke euroazijskog flornog elementa sa 63 vrste (33,87 %) i biljke široke rasprostranjenosti s 38 vrsta (20,43 %). Fitocenološka analiza florističkog sastava pokazuje da ovi travnjaci čine prijelazni položaj između razreda Festuco-Brometea i Molinio-Arrhenatheretea, odnosno da pokazuju prijelazni položaj između redova Festucetalia valesiacae, Brometalia erecti i Arrhenatheretalia.
On gentle eastern slopes of Psunj, dry grasslands are developed. Dry grasslands represent one of the most endangered forms of vegetation, and
were the subject of this research. The terrain is slightly sloping towards the southeast, southern exposure, altitude about 400 m. The aim of the research was to determine the abundance and variety of vascular flora of grasslands in Rudine area. Floristic research was conducted in 2003, 2008, 2016 and 2017. On the surface of about 2500 m2, a list of plant taxa has been compiled and determined by their affiliation with families, floral elements and life forms.One hundred and eighty-six vascular plants of 46 families and 134 genera were recorded. Taxonomic, ecological and phytogeological analysis was carried out. Taxonomic analysis suggests there are 2 species of gymnosperm (1.08%), 155 species
of dicotyledons (83.33%), and 29 species of monocotyledons (15.59%). The analysis of life forms shows that the most represented are 113 species of hemicryptophytes (60.75%), and 29 species of terophytes (15.59%). Plants of the Eurasian floral element with 63 species (33.87%)
and plants with a wide spread of 38 species (20.43%) dominate in phytogeographic analysis. The phytocenological analysis of floristic composition shows that these grasslands are a transient position between
the Festuco-Brometea and Molinio-Arrhenatheretea classes, that is to show the transition between Festucetalia valesiacae, Brometalia erecti and Arrhenatheretalia.
Three-of-heaven (Ailanthus altissima (Mill.) Swingle) is considered as one of the most invasive plant species worldwide in rural and urban environment. Although tree-of-heaven is commonly observed ...throughout the city of Osijek (Croatia), its prevalence and frequency has not been documented. This study has been conducted from May to September 2022 in the streets of Osijek to determine the distribution, abundance and competitive advantage of this species. A survey was performed by sampling randomly selected 20 quadrats in each city district, having together 140 phytocoenological records, and presence-absence of tree-of heaven was recorded in each plot. Where present at urban habitats, the number of threes were recorded and categorized approximately by the diameter at breast height (dbh). Habitats were distinguished as follows: alleys, abandoned private areas, public areas, ruderal sites, cracked walls and road edges. Risk assessment analysis were prepared by combining quantitative (number of trees per plots) and qualitative (four categories: biological characteristics and dispersal abilities, ecological amplitude and distribution, ecological impact, and difficulty to control) data. There was e recorded a total of 189 tree-of-heaven, occurring both as solitary plants or in developed stands. The habitat types with the highest rate of tree-of-heaven are abandoned private areas (34%) followed by public areas (31%). Out of the total, 55% of the recorded tree-of heaven are young individuals belonging to the very small and small diameter classes, and are mainly present on abandoned private and public areas. Ecological impact and biological characteristics are primary course of its landscape spread.
Pajasen (Ailanthus altissima (Mill.) Swingle) je jedna od najinvazivnijih biljnih vrsta širom svijeta kako u ruralnim, tako i u urbanim područjima. Premda je pajasen široko rasprostranjen na području grada Osijeka (Hrvatska), njegova prevalencija i frekvencija još do sada nije zabilježena. Istraživanje je sprovedeno od svibnja do rujna 2022. na osječkim ulicama kako bi se utvrdila njegova distribucija, abundacija i kompetitivna sposobnost. Istraživanje je obavljeno metodom slučajno odabranih kvadrata unutar svakog gradskog kvarta, što je ukupno iznosilo 140 fitocenoloških snimaka. Naplohama gdje je utvrđen pajasen, pobrojane su sve individue i kategorizirane su prema obujmu prsnog promjera stabla. Plohe su razvrstane kao: ulice, napušteni privatni posjedi, javne površine, ruderalna staništa, napuknuti zidovi i rubovi puteva. Procjena rizika pripremljena je kombinacijom kvantitativnih (broj individua po plohi) i kvalitativnih kategorija (biološka obilježja i sposobnostširenja, ekološke amplitude i rasprostranjenost, ekološki utjecaj i poteškoće u suzbijanju). Utvrdili smoukupno 189 stabala pajesena, koji su bili prisutni i kao solitarna drva a također i oblikujući nakupine. Od urbanih staništa, s najvećim postotkom (34 %) pajasen je utvrđen na napuštenim privatnimposjedima a zatim slijede javne površine (31 %). Od ukupno zabilježenih vrsta, 55 % pajasena sumladice koje pripadaju kategoriji stabala s vrlo malim ili malim promjerom debla i uglavnom surašireni na napuštenim privatnim posjedima i javnim površinama. Ekološka i biološka obilježjapajasena primarno su zaslužna za njegovo širenje urbanim prostorima grada Osijeka.
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