Resumo

AYALA-SIERRA, A.  e  VALDEZ-AGUILAR, L. A.. Coir dust as an alternative substrate for plug production of ornamental species. Rev. Chapingo Ser.Hortic [online]. 2008, vol.14, n.2, pp.161-167. ISSN 2007-4034.

To evaluate the feasibility of using coconut coir dust as a growing medium for the germination and initial development of six ornamental plant species, and to determine the possibility to use it as a substitute of Peat Moss this experiment was carried out. The species selected for the study were: Dianthus chinensis (Dianthus), Gazania rigens (Gazania), Tagetes erecta (Marigold), Viola wittrockiana (Pansy), Antirrhinum majus (Snapdragon), and Petunia x hybrida (Petunia). Seeds from the six species were germinated in coir dust, Peat Moss or Peat Lite. Prior to seeding, the coir dust pH was adjusted to 6.2 and it was amended with dolomitic limestone and KNO₃ as nutrient supply. Afterwards, coir dust or Peat Moss was mixed with perlite and vermiculite at a 70:20:10 proportion (v/v), respectively. Peat Lite had 50% Peat Moss and 50% perlite (v/v). A randomized block design with three replications was selected to evaluate the effect of the growing media on plant height, shoot and root dry mass, germination rate, and marketable plants percentage. Shoot height of plants grown in coir dust was decreased significantly in gazania (21%), snapdragons (30%), and petunia (13%), as well as shoot dry mass of snapdragons (24%) and root dry mass of dianthus (22%). Nonetheless, coir dust did not affect plug quality since the marketable plants percentage and germination rate were comparable in coir dust and Peat Moss. It is concluded that coconut coir dust can be used as a growing medium in ornamental plug production and can substitute Peat Moss.

Palavras-chave : Dianthus caryophyllus; Dianthus; Gazania rigens; gazania; Tagetes erecta; marigold; Viola wittrockiana; pansy; Antirrhinum majus; snapdragon; Petunia x hybrida; Petunia; growing media; germination; plant propagation.