Resumo

LAZO, José Vicente  e  ASCENCIO, Jocelyne. Light quality effects on Cyperus rotundus growth. Bioagro [online]. 2010, vol.22, n.2, pp.153-158. ISSN 1316-3361.

Canopy shade is an important part of weed-crop interference, and the aim of this study was to determine the effect of the radiation quality on the growth of Cyperus rotundus. Nutsedge corms were planted in pots filled with soil and placed under red, green or blue cellophane filters, neutral shade with low photon flux density, or full sun exposure. After 48 days, 10 plants of each treatment were sampled. It was found that under neutral shade lower values for the number of tillers and corms, dry root, stolon and leaf biomass, were observed per unit area, which resulted in a lower total dry biomass and leaf area. Differences were found between this environment and full exposure under the red and blue filters, but not under the green filter; it is important to emphasize the larger leaf area ratio found under neutral shade as a consequence of a lower number and corm dry weight as related to the aerial part in terms of dry biomass. These results indicate that management of the shade should be considered as an agricultural practice within an integrated weed control.

Palavras-chave : Purple nutsedge plants; weeds; shade; transmittance.