Banca de DEFESA: ESTER FONSECA DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : ESTER FONSECA DA SILVA
DATA : 31/01/2019
HORA: 09:00
LOCAL: Sala 01 - PPGF
TÍTULO:

Phytosociological survey and weed management in a railway

PALAVRAS-CHAVES:

Chemical control; Community ecology; Atlantic forest; Permanent Preservation Area; mangrove; forest

PÁGINAS: 83
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Matologia
RESUMO:

For decades, weeds have been chemically controlled in railways, as this is the most suitable method for controlling large areas. Weed control strategies should take into account biotic factors, such as the composition of the plant community present in the area, and abiotic factors derived from physical, chemical or physicochemical aspects of the environment such as topography, climate and soil morphophysiological characteristics such as texture, structure, porosity, etc. The chemical control efficiency, the main method used in railway lines, has been questioned about the tolerance and possible resistance of some biotypes of certain species to the most used herbicide, glyphosate. The objective of this work was to carry out the phytosociological survey of weeds in a railroad stretch in the Mata Atlântica biome and to evaluate the presence of glyphosate after application in a permanent preservation area. The phytosociological survey was carried out in a 130 km stretch along a railway network, separated into subareas of Mangue, Floresta and Área Urbana, where collections were made in 10 points per environment, in triplicate, in the center of the main line and a point in sample units for each area. A square of 0.5 m of side was used, randomly tied once at each sampling point for plants, which were harvested according to species and counted. After the species were grouped by family and were calculated the phytosociological indexes density, frequency, species similarity between areas and diversity. The control efficiency and soil glyphosate behavior tests were carried out with in situ tests where the effects of five doses were observed: 0 g. ha-1 (control); 1,440 g.ha-1, 2,160 g.ha-1, 2,880 g.ha-1 (commercial dose) and 5,760 g.ha-1 and the use of adjuvant by comparing different commercial products of glyphosate: Roundup NA® (4 , 5 L pc ha-1), Roundup WG® (2.3 kg pc ha-1) and Pilarsato® (4.5 L pc ha-1); In addition, tests were carried out on greenhouse leaching potential, using soils from two Permanent Preservation Areas (Forest and mangrove). This experiment consisted of applying the commercial product Pilarsato (Glyphosate), commonly used in this area, in vertical column of PVC containing soil from different areas. The doses were: 0g ha-1 (control), 1440g ha-1, 2,160g ha-1, 2,880g ha-1 (commercial dose) and 5,760g ha-1. The application of the herbicide was performed at the top of the columns, followed by simulation of precipitation of 20 mm h-1. After 7 days of treatment, the tubes were sectioned and placed horizontally to receive seeds of Cucumis sativa, bioindicator sensitive to the herbicide. After 15 and 30 days, visual evaluations of the phytotoxicity were performed in the bioindicator and the chlorophyll a fluorescence was evaluated to obtain detailed information on the photosynthetic efficiency of the Cucumis sativa plants. In addition, soil samples were subjected to high performance liquid chromatography (HPLC) for residue analysis. No glyphosate residues were found in the soils under study in either the bioindicator test independent of the chemical methodology. The phytosociological survey indicated similarity in the floristic composition between the Mangue and Urban Area areas, with greater weed infestation in the mangrove area, and the forest area presented greater species richness, being the botanical families Poaceae and Asteraceae the most representative in study. Field tests indicated that there was no difference in weed control as a function of glyphosate tested doses, with or without adjuvant, and the control was effective at 60 days, taking into consideration the reinfestation of weeds, reduced for all doses . In the greenhouse tests there was no leaching or residual glyphosate herbicide. It is concluded that management tactics to be adopted should take into account characteristics of the vegetation composition of each subarea, seeking a better control result, the herbicide glyphosate being satisfactory in the control of invasive plants in APP area at the doses tested regardless of the use of adjuvant, requiring reapplication in 60 days, and that this herbicide did not offer in this study risk of pollution to groundwater.

MEMBROS DA BANCA:
Presidente - 1905333 - AROLDO FERREIRA LOPES MACHADO
Externo ao Programa - 3036150 - JUNIOR BORELLA
Externo à Instituição - MILER SOARES MACHADO - UFV