PEREIRA, N. A. E.; http://lattes.cnpq.br/6511174485244808; PEREIRA, Natali Almeida Evangelista.
Resumo:
Allelopathy refers to the natural release of inhibitory substances by certain
plants capable of interfering with the growth of other in the environment. This
study aimed to identify the allelopathic activity of aqueous extract of S/da
cora/fo//a L. roots, germination and initial growth of lettuce seedlings, green
onions and peppers. The study was conducted at the Seed Analysis Laboratory
and Seedlings of the Center for Science and Technology Agrifood the Federal
University of Campina Grande, in Pombas-PB. Were employed two bioassays
(germination - l and initial growth - 11) in a completely randomized design with
four replications of 25 seeds per treatment for the bioassay of germination and
ave replicates with 10 seedlings for the initial growth bioassay. The aqueous
extracts were obtained from S/da cora/áo//a L. roots of plants of previously dried
and ground in a forced air circulation oven, adding 10 ml of deionized water for
every gram of the obtained powder, the extract was filtered and stored for 48
hours. Before application of the extract, it was diluted with deionized water to
obtain the following concentrations: 20, 40, 60 and 80%, and still used the
concentration of 0% (deionised water) as control. The solutions at different
concentrations were measured osmolarity and then PEG 6000 were prepared in
the same osmolarity of the extracts to obtain a contrai of the osmotic effect on
the germination and growth of the target species under study. Evaluations
consisted of the germination test, first count and germination speed index,
average time of germination and allelopathic effect index for the bioassay l and
length of root and short and total dry mass for the bioassay 11. Data were
subjected to analysis of variance and polynomial regression and significant
data, adjusted equations in arder to analyze the behavior of variables with
increasing doses of the aqueous extract of S/da cora/ão//a L. The aqueous
extract of S/da cord/áo//a L. roots not interfered on the germination of lettuce
seeds, green anion and pepper, however, showed allelopathic activity on the
early development of these seedlings and the effects have proved generally
dose-dependent. But the effect of aqueous extract of S/da cord/ão//a L. on the
initial development of lettuce seedlings, green onions and peppers are not
osmotic or hydrogen ion nature.