Planta Daninha (2010) 28, 301-307

B.A.B. Martins, H.M.C.P. Chamma, C.T.S. Dias and P.J. Christoffoleti (2010)
Germinação de Borreria densiflora var. latifolia sob condições controladas de luz e temperatura
[Germination of Borreria densiflora var. latifolia under controlled conditions of light and temperature]
Planta Daninha 28 (2), 301-307
Abstract: Germination is a fundamental process in weed population dynamics. Thus, this research aimed to evaluate the interaction between temperature and light upon the germination of a new variety of the weed vassourinha-de-botão (Borreria densiflora var. latifolia), under germination chamber conditions. The influence of five temperatures (20, 25, 30 and 35 ºC constant and alternated 20-30 ºC), in presence of 12h-photoperiod and constant dark conditions upon the germination was studied, under a randomized complete-block design, with four replications. Accumulated germination percentage and germination speed were evaluated, being the latter evaluated through the germination speed index. Data were submitted to analysis of variance through F test, followed by Tukey test at probability of 0.05. Germination occurred preferentially in presence of light, with significant interaction only between temperature and presence of light. We observed, thus, the positive photoblastism of this new variety of B. densiflora. The highest germination percentage occurred under the alternated temperature 20-30 ºC, followed by the temperatures 25, 30 and 35 ºC, and the germination speed increased with the increase of the temperature. The results obtained in this research show that the population dynamics of this weed is influenced mainly by thermic amplitudes, higher temperatures (over 25 ºC) and conditions of presence of light, explaining, therefore, its occurrence in the North and Northeastern tropical regions of Brazil.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Database assignments for author(s): Pedro Jacob Christoffoleti

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Spermacoce densiflora (weed)		Brazil (NE)