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Optimizing of weed control in carrot anf lettuce
Šuk, Jaromír ; Jursík, Miroslav (advisor) ; Kolářová, Michaela (referee)
The main aim of this work was to made literary review about possibilities of weed control in carrot and lettuce. The experimental part of this work was focused on optimization of herbicides weed control in lettuce and carrot. Small plot field trials were carried in 2015.
Literary review was focused on the summarizing of information about the particular vegetables. Futhermore, the available literature about weed control in these vegetables were complied, specialy with a focus on mechanical and chemical (herbicide) control. The last section of review is dedicated to optimizing use of herbicides that are not registered in tested vegetables.
In lettuce, herbicidal efficacy was assessed on Chenopodium album, Amaranthus retroflexus, Mercurialis annua and Echinochloa crus-gali and selectivity of herbicides to crop. In carrot, herbicidal efficacy was assessed on Amaranthus retroflexus, Solanum physalifolium, Chenopodium album, Echinochloa crus-gali and Mercurialis annua and selectivity of herbicides to crop.
Lettuce was treated by herbicide combinations with active ingredients: befor planting or postemergence pendimethalin, postemergence propyzamide, postemergence phenmediphan, postemergence dimethenamid and postemergence pethoxamide. Carrot was treated by herbicide combinations with active ingredients: preemergence aclonifen, preemergence clomazone, preemergence dimethenamid, preemergence pendimethalin, postemergence linuron and postemergence metribuzin.
In lettuce, were on the plots, where were used pendimethalin and dimethenamid. In carrot, best weed control were on the plots, where were used aclonifen, clomazone and dimethenamid. However, after application these herbicides, highest phytotoxicity was found. The lowest selectivity to both tested vegetables showed dimethenamid.
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Occurrence of invasive species Eragrostis albensis in Prague and its surroundings
Mikulka, Jakub ; Holec, Josef (advisor) ; Jursík, Miroslav (referee)
Eragrostis albensis is an invasive weed. For invasive species it is typical that they are easily spread in to all manner of localities. Eragrostis albensis is recently described species, which spreads along the Elbe and the Vltava river. The purpose of this bachelor thesis was to find new places of occurrence in Prague and its surrounds and especially around the Vltava river. There were found a few locations where the occurrence of Eragrostis albensis was confirmed and these areas were always ruderal. At most of the areas there were maximum 3 plants. Only in one locality there were over 70 plants of Eragrostis albensis (locality Dvořákovo nábřeží). This invasive weed has wide ecological amplitude, it occurs especially on embankment nearby river, but it can also grow on pavements affected by dry. This species well tolerate disturbed areas and floods can help this weed to create new suitable locations. According to this monitoring it´s obvious, that Eragrostis albensis is a part of some ruderal districts in Prague.
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Optimizing of weed control in Brassica vegetables
Ondra, Michal ; Jursík, Miroslav (advisor) ; Václav, Václav (referee)
Small plot field experiment carried out in 2015 on Demonstration and experimental field of Czech University of Life Science in Prague. Objective of the experiment was get new knowledge of efficiency and selectivity of selected herbicides in kohlrabi. Main objective of the experiment was described of influence of irrigation and use of adjuvant on efficiency and selectivity of herbicides. The kohlrabi was growed from transplant. Herbicides were applicated five days after transplanting. Herbicides were applicated in few variant: separately, with adjuvant, two level of irrigation (basic irrigation 15 mm / intensive irrigation 65 mm). During growing season rained 70 mm. Efficiency and selectivity of herbicides was assessed by estimation method using a percentage scale from 0 to 100 %. Efficiency of herbicides was assessed on weeds: Thlaspi arvense, Chenopodium album and Solanum nigrum. Next objectives were: yield of above ground biomass and market tubers, weight of roots, contain of vitamin C, glucosinolates and herbicide residues in tuber.
Efficiency of herbicide Stomp 400 SC was significantly higher than efficacy of Butisan 400 SC on Thlaspi arvense and Chenopodium album. Intensive irrigation caused higher efficiency. On the other side tank mix of herbicides and combination herbicides with adjuvant caused insignificantly higher efficiency. Butisan 400 SC had the highest effectivity on Solanum nigrum compared to efficacy of herbicide, Stomp 400, but efficiency efficacy of herbicide Stomp 400 SC was sufficient.
Stomp 400 SC demaged kohlrabi more than Butisan 400 SC, especially on plots with intensive irrigation. Herbicide Stomp 400 SC had negative influence on roots. On plots treated by herbicide Stomp 400 SC was showed lower weight of roots about 56 % compared to hand-weeding plots.
Kohlrabi on plots treated Stomp 400 SC with intensive irrigation produced not market weight of tuber (less than 200 g/plant) in harvest time. From these reason, the harvest time must have been put off one week. Residues of metazachlor (Butisan 400 SC) were not detected in tuber. Residue of pendimethalin (Stomp 400 SC) was found on every plots treated by herbicide Stomp 400 SC. Found concentration of pendimethalin was not higher than maximal residue limit (0,05 mg/kg). The highest concentration of vitamin C and glucosinolates was found in tuber damaged by tank mix combination of Butisan 400 SC + Stomp 400 SC. On the other side the lowest concentration of vitamin C and glucosinolates was found in tuber from hand weeding plots, but differences among treatments were not significantly.
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