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Biology, occurrence and regulation Apera spica-venti tufted crops grown.
ORNA, Vítězslav
Over the last decades the amount of weeds in our fields have noticeably decreased. The easily annihilated and susceptible species were almost eradicated by means of herbicides and agrotechnical operations. Their place was taken by more resistant species, which are a huge problem for the farmers. For this purpose I decided to make an experiment under the working circumstances. I observed the occurrence of the weeds in certain localities. Especially I concentrated on the silky bent grass (Apera spica-venti), on its occurrence, regulation, extension and susceptibility or resistance to certain herbicides. The effect of the tested herbicide combinations was statistically significant for silky bent grass as well as for the other weeds (P 0.05). The coach grass was the only exception, where the effect of these preparations was not proved, as well as Vicia cracca, Lamium purpurem, Galium aparine, Geranium pusillum (P > 0.05). However the coach grass appeared among these inconclusively responsive weeds more frequently. (P >0.05). As the results of experiment showed, the most effective combinations for elimination of the silky bent grass (Apera spica-venti) were Sumimax + Glean, Cugar Forte + Glean + Dural a Cugar Forte + Logran. All these combinations were proved to be 100% effective against the silky bent grass (Apera spica-venti). The other combinations were not 100% effective. These comprised Rapsan + Command+ Grounded with 89 % effectivity, Sumimax + Logran 91 % effectivity a Butisan+ Clomate+ Grounded 67 % effectivity. The results show that the silky bent grass (Apera spica-venti) is more susceptible to some herbicide combinations and in the fields it can be successfully reduced. On the contrary the silky bent grass (Apera spica-venti) is resilient to some other agents. From this point of view the right choice of the herbicides is crucial in next year.
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The control of weeds in maize stand (\kur{Zea mays L.})
VANĚK, Robert
Some of weeds have disappeared owing to the plant production specialization; some of them have become more resistive. Those weeds have taken significant role due to its danger and frequency of presence. The thesis is mainly focused on description of biology and morphology of weeds, possibilities of weeds spread and weed control. Methods of mechanical and chemical regulation are described based on these facts. The experiments, which were carried on maize, determined the effect of selected herbicide and its active substance on weed control. Following precautions, which were suggested, have led to successful suppression of specific significant weeds.
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Ways to control Silky bent grass in cereals stands
ORNA, Vítězslav
Currently, weeds are the most problematic group of harmful agents in the plant protection. A major problem are the weed species resistant to herbicides, minimize soil preparation and increasing the proportion of winter cereals in the crop rotation. Among the species represented with large increase in our fields belongs silki-bent grass (Apera spica-venti L.). For this reason, was found an herbicidic attepmt in cereals and research the number of weeds and effectiveness of herbicides against the weeds on the individual checkpoints .
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Biology, occurrence and control Cockspur Grass(\kur{Echinochloa crus-galli} (L.) Beauv.)on arable land
VITURKA, Martin
This work is focused on the occurrence of Cockspur Grass (lat. Echinochloa crus-galli) on arable land and ways and means of its regulation. Damages which are annually caused by weeds are very difficult to quantify and their negative impact is reflected every year in all crops and all fields. Cocksour Grass belongs among the most dangerous weeds, especially in wide-row stands. Furthermore, I focused on the issue of late weed, seed dormancy and resistance of populations. A related question is possible solution to the protection of stands against weeds using both preventive and direct methods of control plants. An experiment was made to check influence of herbicides on the population of Cockspur and other weed species which occur in this root-crops. The result showed which kind of herbicide is more effective with pre-emergence application to Cockspur Grass and other monitored weeds.
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Biology and control of Redroot pigweed (Amaranthus retroflexus L.) on arable land
BENDÍK, Jiří
This work is focused on pigweed species-related issues, particularly those of redroot pigweed (Amaranthus retroflexus L.), including biology, occurrence, harmfulness, spreading and possibilities to regulate the plant, which, nowadays, ranks among very dangerous and constantly spreading weed species. I therefore monitored the frequency of occurrence of redroot pigweed and other weed species grown on experimental plots during the maize vegetation season, and the effectiveness of weed regulation efforts through three registered herbicides, namely Adengo, Milagro and Callisto 480 SC. All three herbicides were appreciably very effective on redroot pigweed and delivered results proved the necessity of applying herbicides to control weed populations in today?s agricultural practices. In this respect, it can indeed be noted that a long-term regulation must be based on principles of good agro-technology practices and combine effectively sowing procedures, chemical protection and other both direct and preventive procedures.
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