No abstract

Bracken (Pteridium aquilinum (L.) Kuhn) is cosmopolitan fern, found at varying altitudes on all continents except Antarctica. It is an aggressive colonizer and can appear in various plant communities, but an important characteristic is its ability to dominate in dense patches. Once establish, the deep-set rhizomes are nearly impossible to eradicate. In Croatia, bracken dominate on specific habitat type called “bujadnice” in Lika region, but can also be found in herbaceous layers in following forest communities: As. Betulo-Quercetum; As. Pteridio-Betuletum; As. Potentillo albae-Quercetum pubescentis; As. Castaneo sativae-Fagetum; As. Helleboro nigri-Piceetum. Bracken fern is significant problem for livestock-based extensive agriculture, because it causes a range of syndromes in farm animals including thiamine deficiency, acute hemorrhagic syndrome, bright blindness, enzootic hematuria and upper alimentary carcinoma. Man may consume the toxins of bracken either directly or indirectly. In terms of the economic loss and suffering caused by bracken, it is clearly that some steps must be taken to control distribution of this fern. Timing is important in any management treatment of bracken fern. The most effective time for bracken control is summer just after the new fronds have fully expanded and starch reserves in the rhizome are at their lowest level. Two or more annual treatments and combinations of cutting and herbicide are more effective than single treatments or even single annual treatments.

Watermark, Tensiometer and Time Domain Reflectometry (TDR) are commonly used soil water sensors in irrigation practice whose performance depends on soil type, depth and growing conditions. Here, the results of sensor performance evaluation in different soil depths as well as the field and laboratory testing in silty clay loamy soil are presented. Gravimetric soil moisture samples were taken from sensor installation depths (10, 20, 30 and 45 cm) and used as reference Soil Water Content (SWC). The measurements varied significantly (p < 0.05) across the monitoring depths. On average across the soil depths, there was a strong negative linear relationship between Watermark (r = −0.91) and TDR (r = 0.94), and a moderate negative (r = −0.75) linear relationship between SWC and Tensiometer. In general, Watermark and Tensiometer measured SWC with great accuracy in the range of readily available water, generated larger Mean Difference (MD) than TDR and overestimated SWC, while TDR underestimated SWC. Overall, laboratory testing reduced the root mean square error (RMSE, Watermark = 1.2, Tensiometer = 2.6, TDR = 1.9) and Mean Average Error (MAE, Watermark = 0.9, Tensiometer = 2.04. TDR = 1.04) for all tested sensors.

Štefanić E., Kovačević V., Antunović S., Japundžić-Palenkić B., Zima D., Turalija A., Nestorović N.: Floristic biodiversity of weed communities in arable lands of Istria peninsula (from 2005 to 2017). 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.

The metals such as Fe, Cu, Zn and Mn are the essential elements that have an important role in the human immune system. The aim of this research was to determine the concentration of nutritive values of macroelements (N, P, and K) and microelements (Fe and Zn) in a mushroom substrate and in a champignon mushroom fruiting body. A trial was conducted in the mushroom production company Romanjek LLC in Slavonski Brod, Croatia. It was conducted in four vegetation cycles on two different substrates, the one originating from Eastern Europe and the other originating from Northern Europe. At the end of the trial, the basic chemical properties of substrates and mushrooms were recorded. A comparison of investigated substrate measurements demonstrates that the highest content of elements N, P, and K was determined in the substrate 2 originating from Northern Europe, while the concentration of microelements Fe and Zn was higher in substrate 1, originating, from Eastern Europe. There was a statistically significant difference in a macroelement content in the mushrooms grown on the substrates of different origin, as well as in the transfer of Zn and Fe from a substrate to mushrooms. There was a higher accumulation of the transferred Zn in comparison to Fe in the mushrooms regardless of the origin of the substrate.