Banca de DEFESA: ELIELTON GERMANO DOS SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : ELIELTON GERMANO DOS SANTOS
DATA : 07/03/2022
HORA: 07:30
LOCAL: Google meet
TÍTULO:

PHYTOSOCIOLOGY AND WEED CONTROL IN SUNFLOWER CULTURE IN THE PARECIS REGION – MT.

PALAVRAS-CHAVES:

Helianthus annuus L.; phytosociology; weeds; control.

PÁGINAS: 44
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Matologia
RESUMO:

Sunflower has a slow initial growth, which makes it very sensitive to weed interference, making it necessary to plan strategies to minimize the effects of these interferences. Therefore, the objective of this study was to identify the weeds present throughout the crop cycle and to evaluate and compare the effectiveness of herbicides applied in the control of weeds in the sunflower crop. The survey was carried out in three areas cultivated with sunflower at different stages of crop development (35 and 100 days after emergence). The square inventory method (0.25 x 0.25 m) was used randomly launched 160 times between the rows of the crop. The plants were identified according to species, popular name and family. Then, the following were calculated: frequency, relative frequency, density, relative density, abundance, relative abundance, importance value index, relative importance value index and similarity index of areas and times. Allied to this strategy, the use of pre-emergent herbicides to control weeds becomes essential, however, little is known about the selectivity of herbicides for the crop. To evaluate the effects of herbicides, a randomized block design was used, with treatments in a 4 x 2 + 2 factorial scheme, with four replications, in which the first factor represented the herbicides s-metalachlor (1920 g ai ha-1 ), sulfentrazone (600 g ai ha-1), flumioxazin (40 g ai ha-1) and trifluralin (1780 g ai ha-1), the second the two controls, one weeded and the other without application and without weeding, and the third two types of soil (sandy and clayey). The application of herbicides was carried out in pre-emergence of the crop, using a CO2 pressurized back sprayer. Phytotoxicity evaluations of sunflower and weed control plants were carried out at 7, 14, 21 and 28 days after emergence. At full flowering of the sunflower, height and stem diameter were determined. After the physiological maturation phase, the head diameter, weight of a thousand achenes and yield were quantified. It was found that the most representative species in the studied areas were Bidens pilosa and Euphorbia hirta with a relative importance index higher than 15% in both periods evaluated. When weed control was not carried out, there was a reduction of up to 10.3% in productivity. The herbicides s-metalachlor, flumioxazin and trifluralin showed the best weed control. There was no effect of phytotoxicity on the crop, which is due to the low rainfall during the test.

MEMBROS DA BANCA:
Presidente - 221918004 - MIRIAM HIROKO INOUE
Interno - 101366004 - MONICA JOSENE BARBOSA PEREIRA
Externo à Instituição - KASSIO FERREIRA MENDES - UFV