Acta herbologica

Stellaria media (L.) Vill. (common chickweed) - strong or weak competitor in the autumn and early-spring sown crops?

2025-01-02T15:02:41+01:00

Because of its ability to produce large numbers of seeds under cool temperatures, S. media rapidly colonizes any cool, moist area before winter or spring crops can become competitive. It is most commonly a weed in many crops in temperate and subarctic climates, where it is often one of the ﬁrst weeds to appear in spring. S. media is one of the most common weeds in spring and winter cereal stands, the most frequent weed in winter oilseed and peas, highly competitive weed in seedling alfalfa, serious weed in citrus, one of the prevailing weeds in strawberry, and one of the most frequent weed species present in conventional sugar beet. It is a principal weed problem in vegetable production and in gardens and turf in almost every country in temperate part of the world.

From the other side, in comparative trials of weed competition and yield suppression in many crops, S. media was found to be less competitive than Avena fatua, Alopecurus myosuroides, Raphanus raphanistrum, Polygonum persicaria, Chenopodium album, Galium aparine and many others weeds. In trials in autumn and early-spring sown crops and established crop plants, such as established alfalfa, S. media was found to be minor competitors, unless present at high densities. The actual competitive effect and associated yield reduction caused by S. media will depend on a number of factors, including time of emergence in relation to the crop. S. media displays vigorous early growth and will cause the greatest yield losses when it emerges at the same time or before the crop. It is also a highly plastic species, meaning that early establishment and resource capture will result in larger more competitive individuals.

A contribution to the knowledge of the distribution of some invasive plant species in Sarajevo Canton

2025-01-02T15:02:42+01:00

During the three-year field research (2019-2022) in the area of Sarajevo Canton, we discovered many invasive plant species in localities where take had not been recorded before. Among them, Ailanthus altissima (Mill.) Swingle, Ambrosia artemisiifolia L., Armoracia rusticiana Gaertn., Mey et Scherb. and Reynoutria japonica Houtt. stand out in particular due to their abundance and coverage. This study aimed to provide data on the localities where these invasive plants were found, including altitude, longitude and latitude, soil type and their floristic and phytocenotic features. The data from these localities should contribute to the creation of a database that can be used for more efficient fight against the aforementioned invasive species. In total, 42 new localities were recorded for Ailanthus altissima, 10 for Ambrosia artemisiifolia, 5 for Armoracia rusticiana and 15 for Reynoutria japonica. Due to their abundance and appearance, Ailanthus altissima and Reynoutria japonica have already become a big problem for urban horiculture in Sarajevo, while the Ambrosia artemisiifolia poses a healt concern, and therefore, urgent measures and necessary to remove them.

In vitro evaluation of antifungal activity of Artemisia species essential oils (A. absinthium, A. dracunculus and A. vulgaris)

2025-01-02T15:02:42+01:00

Due to the trend to reduce the use of synthetic pesticides and the increasing attention to environmental protection, research in the field of allelopathy, especially allelochemicals that can be used for the synthesis of biopesticides, has been intensified in recent decades. The genus Artemisia belongs to the family Asteraceae and includes a large number of aromatic and weedy species (about 500), which are known as a significant source of biologically active compounds characterized by allelopathic effects. Therefore, the aim of this study was to investigate the effect of essential oils from three species of the genus Artemisia (A. absinthium, A. dracunculus and A. vulgaris) on the mycelial growth of different isolates of the phytopathogenic fungus Colletotrichum orbiculare, the causal agent of anthracnose of Cucurbitaceae hosts in vitro.

The antifungal activity of the essential oils in in vitro tests was determined using the disc volatilisation method. The essential oils were applied directly in amounts of: 1, 5, 10, 15 and 20 µl for A. dracunculus and A. vulgaris, i.e. 10, 15, 20, 25, 30 µl for A. absinthium. The average IC₅₀ values were 4.36, 7.12 and 17.63 µl ml^-1 of air phase for A. vulgaris, A. dracunculus and A. absinthium, respectively. According to the IC₅₀values obtained, the essential oil of A. vulgaris showed the strongest antifungal potential, while the essential oil of A. absinthium showed the weakest inhibitory effect.

Raman specroscopy as appropriate tool for chemical discrimination of wild hemp oil seed samples

2025-01-02T15:02:42+01:00

Wild hemp (Cannabis sativa L. ssp. sativa var. spontanea Vavilov), as a whole plant, especially its seeds are highly valued, with significant place in the production of oil-based paints, in creams as a moisturizer, for cooking, animal and bird feed. This work represents an innovative report focused on the evaluation of the phytochemical composition of wild hemp seeds grown in two different locations in Serbia, using Raman microspectroscopy in combination with multivariate data analysis. Some significant differences were found between the analyzed oil samples in terms of chemical profile. The Raman spectra of the wild hemp seed samples indicate the predominance of unsaturated (1657 and 1268 cm^-1), then saturated fatty acids (1443, 1306 and 1084 cm^-1) and fatty acid esters (1745 cm^-1) due to the higher intensity of the bands. The relative intensities of these bands may indicate that the seed oil of wild hemp from two different locations differs in the content of unsaturated and saturated fatty acids, as shown by the differences in the relative intensities of 1657 and 1268 cm⁻¹.

Nozzle type and adjuvant selection influence on nicosulfuron efficacy on some common weeds in maize (Zea mays L.)

2025-01-02T15:02:43+01:00

The field experiment was conducted during 2021 and 2022 at the Maize Research Institute Zemun Polje, Zemun Polje in Serbia. The goal of this study was to evaluate the influence of adjuvants and nozzle types on the efficacy of two herbicides based on the same active ingredient - nicosulfuron. The study was arranged as a split-block design in four replication with 12 treatments plus weed-free as well as weedy season long treatments. 21 day after treatment (DAT) weeds were sampled and both fresh as well as dry biomas were measured (only dry biomass showed). Visual estimation of efficacy was assessed 7, 14 and 21 DAT. Among all treatments no differences between herbicides were observed. In addition, treatments with AMS caused a rapid decrease of efficacy compared to treatments with non-ionic surfactant (NIS) adjuvant where the efficacy was increased and where it lead to faster weed decay. By dry biomass reduction, all factors had statistically very significant impact both as individual and in mutual interaction, on the resaults except on Bilderdykia convolvulus where nozzle impact was not statistically signifiacant.

Soil weed seed bank in the function of biodiversity

2025-01-02T15:02:43+01:00

The effect of intensive agricultural practises on weed composition is well described for the aboveground flora, but less research has been done on how the impact might affect the soil weed seed bank. For this reason, during three years (2014-2017), the soil was sampled and the number of weed seeds in the soil was estimated by eight different management systems: (i) monoculture of maize, winter wheat and soybean, (ii) 2-year crop rotation (maize - winter wheat) with and without application of mineral fertilizer, (iii) 3-year crop rotation (maize - winter wheat - soybean) with mineral fertilizer, with manure and without application of fertilizer. The estimated soil weed seed bank was used to calculate the α and β diversity indices and determine the diversity, richness and uniformity of the weed community. The diversity indices confirmed that the diversity of the weed community is influenced by the strategy of crop rotation and the type of fertilization, that in the monoculture of winter wheat the diversity, the number of dominant weed species and the uniformity od weed community are the lowest, while in the 3-year crop rotation with mineral fertilization it is the richest biodiversity and weed community uniformity