The response of two populations (CC1, 43.59°N & 20.40°E; CC2, 44.46°N & 20.17°E) of common cocklebur ( Xanthium strumarium L.) to nicosulfuron was investigated both in field experiments and in the ...laboratory. Population CC1 had no history of treatment with any herbicide, while population CC2 was treated with ALS inhibitor herbicides for six consecutive years. In the field, plants were treated post-emergence with nicosulfuron (0, 10, 20, 40, 60 and <st1:metricconverter ProductID="80 g" w:st="on">80 g</st1:metricconverter> ai ha-1) at four true leaves. Visual injury estimation and vegetative parameters (plant height, fresh weight, leaf area) were recorded about month after herbicide application. The acetolactate synthase (ALS) enzyme activity in response to herbicide concentrations of 0, 0.01, 0.1, 1, 10, 100 μ M was determined in vitro . GR50 values for vegetative parameters and I50 values for ALS activity were slightly greater for the CC2 than for the CC1population, but the results confirmed that neither population was susceptible to nicosulfuron. Namely, based on results for fresh weight, the population CC1 was about 3.9 and 2.6-fold more susceptible to nicosulfuron than population CC2 in two consecutive years, but differences were not so prominent for other parameters (plant height, leaf area and ALS activity), ranging from 1.18 to 1.8-fold. The differences between population CC1 and CC2 could be attributed to inter-population variability in susceptibility to nicosulfuron or could be the consequence of repeated application of ALS herbicides to the CC2 population during the six previous years. Future investigations are necessary in order to clarify this dilemma.
This study focuses on content analyses of internet marketing communication tools and techniques used by Destination Management Organizations (DMOs) on their official websites. The population of the ...study includes two regional DMOs of six European countries each, situated by the sea, as well as all Croatian regional DMOs also by the sea. The results show that DMOs are not fully applying internet marketing tools and techniques on their official websites in their communication with the market and public.
Given the importance of different weed management systems (MS) for weed communities and soil seed bank, our aim was to study the impacts of organic (Org) and conventional (Conv) MS in tomato and ...sugar beet on the abundance of weeds and weed seed bank. The results have shown that in both crops the aboveground weed flora is dominated by 2–3 species in the Conv MS, while it is more diverse in the Org MS. In both crops the soil seed bank is less diverse when compared with the aboveground weed flora. Furthermore, a comparative analysis of the weed flora and soil seed bank has shown a high number of different weed seeds in the soil for tomato, unlike sugar beet, where a higher number of weeds was determined in the aboveground weed flora. In tomato, the soil seed bank is more diverse in Org MS (4.1 ± 1.5) than in Conv MS (3.8 ± 1.3), which was also true for the aboveground plant biodiversity (4.6 ± 1.1 vs. 3.6 ± 1.5 species, respectively). Also, although the differences in aboveground weed density and abundance in tomato were not statistically significant, seed bank reserves in the Org MS were significantly more abundant (40.4 ± 16.7 weed seeds vs. 4.5 ± 3.6 in Conv MS). This study has also shown that in sugar beet there were practically no differences between Org and Conv MS, even though the abundance of its aboveground weed flora was higher in Org MS (70.2 ± 29.4 vs. 38.1 ± 21.2 plants/m
2
in Conv MS). In conclusion, it can be said that although both MS had similar effects on weed management in tomato, for sugar beet Org MS has proven to be less effective in weed control.
The paper is based on the assumption that the participants in an exchange process can positively influence many aspects of their own businesses, if they master the knowledge and skills in the field ...of business negotiation. The aim of the paper is to contribute to the knowledge of the specific characteristics of negotiation in the corporate banking market and of the impact of individual sources of negotiation power on the agreed terms of exchange between the banking customer and the bank. The conducted research has shown that banking customers can directly influence the terms of exchange in the corporate banking market. Furthermore, the research has shown the influence that the individual sources of negotiation power have on the achievement of more favourable terms of exchange for corporate banking customers. Implications of the conducted research are multiple. For instance, the results of the research provide guidelines to corporate banking customers as to how to develop an effective negotiation strategy in the corporate banking market, thus helping them to achieve higher business competitiveness.
Herbicide application has long been considered the most efficient weed control method in agricultural production worldwide. However, long-term use of agrochemicals has numerous negative effects on ...crops and the environment. Bearing in mind these negative impacts, the EU strategy for withdrawing many herbicides from use, and modern market demands for the production of healthy and safe food, there is a need for developing new effective, sustainable, and ecological weed control measures. To bring a fresh perspective on this topic, this paper aims to describe the most important non-chemical weed control strategies, including ecological integrated weed management (EIWM), limiting weed seed bank, site-specific weed management, mechanical weeding, mulching, crop competitiveness, intercropping, subsidiary crops, green manure, and bioherbicides.
The effects of several bacterial media Bacillus licheniformis population 1
(MO1); B. licheniformis population 2 (MO2); B. subtilis (MO3); B. megatherium
(MO4); humates (MO5) on seed germination of ...Datura stramonium L., Abutilon
theophrasti Med., Onopordon acanthium L. and Verbascum thapsus L. were
tested. Seeds were germinated in Petri dishes containing solutions with
different bacterial media. The highest germination percentage in all
treatments was recorded for V. thapsus seeds (100.0%). Different treatments
had diverse effects (stimulative or inhibitory) on seed germination of D.
stramonium from 5% (MO1) to 13.3% (MO3), with 10.0 % in H20, A. theophrasti
from 28.3% (MO3) to 65.0% (MO5), with 43.3 % in H20 and O. acanthium from
10.0% (MO2) to 13.3% (MO1 and MO3), with 6.7% in H20, depending on the type
of media and weed species.
As photosynthesis is the basic process during which light energy is absorbed
and converted into organic matter, the importance of the plant pigment
chlorophyll (a and b forms) as an intermediary in ...transformation of the
absorbed solar energy and its activity in the process of photosynthesis and
synthesis of organic substances in plants are crucial. Therefore, this paper
provides an overview of methods for monitoring the optical activity of
chlorophyll molecules and methods (non-destructive and destructive) for
quantification of chlorophyll in plants. These methods are used to estimate
the effects of different stress factors (abiotic, biotic and xenobiotic) on
the efficiency of photosynthesis and bioproductivity, aiming to assess the
impact that these limiting factors have on the yield of various cultivars.
Also, those methods for analysis of chlorophyll optical activity and/or
content are appropriate for assessing the reaction of weed species to
different agricultural practices (mineral nutrition, treatment by herbicides,
etc.) and studies of different aspects of weed ecophysiology and their
influence on crop harvest.
Studies of biological characteristics of seeds and conditions for their
germination have a major importance for planning and executing rational
measures of weed control. The aim of this study was to ...investigate the effect
of different temperatures on germination of C. campestris seeds. Three
treatments (T1- storage at room temperature; T2 - exposure to 4?C for 30
days; T3 - scarification by concentrated sulphuric acid) differing in
manipulation with seeds before germination were tested at different
temperatures (5?C, 10?C, 15?C, 20?C, 25?C, 30?C, 35?C, 40?C, 45?C).
Germinated seeds were counted daily for ten days and the length of seedlings
was measured on the last day. The results showed that differences in
germination of C. campestris seeds were very prominent between temperatures,
as well as between treatments T1, T2 and T3. Seeds failed to germinate at 5?C
and 45?C in all treatments (T1, T2, T3). Germination ranged from 6.25 at 10?C
to 96.88%, the highest percentage, achieved at 30?C.
Portulaca oleracea L. is one of the most widely distributed plant species, invading a host of worldwide regions. Rivers and canals, as corridors connecting neighboring habitats, are known to exhibit ...high invasion levels. Consequently, the aim of this paper was to show which catchment areas, environmental factors and habitat types can be seen as predictors of the presence of this invasive species in the riparian areas of Serbia. Field research was carried out at 250 field sites, where the cover and abundance of P. oleracea, relevant environmental variables and habitat type were recorded. Redundancy analysis (RDA) and response curves fitted using a generalized linear model (GLM) were used to show the relation of the cover of P. oleracea and the following variables: catchment area, predominant bank material, elevation, and the total number of invasive species on site. A non-metric multidimensional scaling (NMDS) was used to group sites where P. oleracea was found, based on the values of its cover. In general, primarily the rivers in the northern, low-lying part of Serbia can be seen as important corridors of the spread of P. oleracea. Its dominance is especially associated with areas draining into the Danube and Sava rivers and field sites characterized by a high pressure of invasive plants. Of the total number of records, the highest number of invaded field sites was recorded along the Danube, Tisa and Zapadna Morava rivers. Regarding the environmental and habitat predictors, the results have shown that the abundance of P. oleracea is associated with gravelly and sandy banks and grassland habitat types, primarily anthropogenic herb stands.
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