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Biology, presence and methods of weeds regulation on a land planted with permanent grasses.
ONDRÁK, Aleš
This thesis is aimed at biology, presence and methods of weeds regulation on a land planted with permanent grasses. Lately, ruderal weed species have been spreading uncontrollably throughout the lawns. It is very difficult to control their occurrence and also very economically challenging. Therefore, the farms should focus more on the possibilities of preventing excessive weed infestation and they should also define and apply the cheapest and the most favorable precautions. On the grassland, which belongs to the ZD Třebelovice, were observed the most abundant weed species. The weeds which occurred the most were: Taraxacum Officinale, Rumex Obtusifolius L, Ranunculus Repens L., Geranium Pratense L., and Urtica dioica L. The influence of the individual hay cuts on the occurrence of the chosen weed species was monitored. The influence of various herbicides was also the matter of observance. The componential task was to appraise the achieved effect after applying chosen herbicides on the weed species.
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Adventitious sprouting of short-lived plants in natural populations
MALÍKOVÁ, Lenka
Disturbance is one of most important selective factor causing removal of plant biomass. Man-made habitats are characterized by strong and unpredictable disturbances, providing bare soil surface colonized by plants with short life cycle. Populations of the short-lived plants are, however, vulnerable to the strong disturbance removing all stem parts with reserve axillary meristems in the case it occurs before plant flowering and fruiting. Nevertheless, 2 % of annual and 14 % of biennial plants are able to overcome meristem limitation by adventititous sprouting from hypocotyle or/and roots. This thesis is composed of four original studies describing the occurrence of adventitious sprouting in natural populations of 22 monocarpic weeds of Central Europe and one species in Indonesia. The studied phenomenon was analyzed in relation to various environmental factors and plant traits in the field and in experimental conditions.
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Mechanical and chemical control of perennial weed
ŠMÍDA, Petr
Perennial weed creeping thistle and couch-grass were controlled for tree year period in Prepychy village (Rychnov nad Kneznou district). Stubble breaking had cardinal effect on regeneration of hypogenous vegetative organs both wedd and endorsed their appearance. Following ploughing and ground reproduction before seeding didn´t control these weed. In chemical control section was tested an effectiveness of 22 herbicides. Creeping thistle showed the highest sensitivity against the majority of herbicides in growth phase F4 (stalk height 20 cm). Results of experiments showed an importance of application a.i. glyphosate in perennial weed control system. In winter wheat vegetation showed herbicides Husar and Lontrel 300 the highest effect against creeping thistle. Broad-leaved crops give a possibility to use graminicides against couch-grass. Graminicides Fusilade Forte 150 EC and Gallant Super shown the highest effect against couch-grass.
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