Potential of Pinus sp. needles for use as substrate conditioners in the production of ‘Trifoliata’ rootstock in greenhouses

• Autor(a) principal: Ceccagno, Henrique
• Data de Publicação: 2019
• Outros Autores: Souza, Paulo Vitor Dutra de, Schafer, Gilmar, Avrella, Eduarda Demari, Fior, Claudimar Sidnei, Schwarz, Sergio Francisco
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/198226
• topic: Porta-enxerto; Melhoramento vegetal; Poncirus trifoliata; Limoeiro trifoliado; Protected environment; Seedling production; Physical and chemical properties; Ambiente protegido; Producción de plántulas; Propiedades físicas y químicas

Seasonality and lack of organic substrates suitable for the production of citrus rootstocks are the main problems in seedling production, coupled with the fact that these materials have alkaline pH. The objective of this study was to evaluate the effect of substrates composed of Pinus sp. needles and a commercial alkaline substrate at different concentrations on the growth and development of Poncirus trifoliata (L.) Raf rootstock. The development of ‘Trifoliata’ was assessed in different mixtures (v:v) of a commercial substrate (Vida®) based on eucalyptus bark and Pinus sp. needles (0, 25, 50, 75 and 100 %) with two particle sizes (3.5 and 8.0 mm). A randomized block experimental design with 10 treatments of seven plants each and four replications was used. During rootstock development, we monitored: the pH, electrical conductivity and stability of the substrates; the dry mass of the aerial part, roots and stem; and vegetative growth and development. Increasing the proportion of needles in the mixture with alkaline substrate reduced the pH, electrical conductivity and density. Treatments with 3.5 mm needles showed greater stability than those with 8 mm ones. The use of 25 % needles provided better results compared to 0 % (alkaline substrate only); however, the need for a specific fertilization and irrigation system for each treatment was detected, as each new substrate has its own physical and chemical characteristics.