Sandra Rieth

Substratos e recipientes para a produção de porta-enxertos de citros irrigados por subcapilaridade

In the production of citrus seedling, the knowledge of rootstock substrate and container is essential to define the entire substantial period to produce quality seedling. The objective of this research was to evaluate seedling emergence and vegetative development of six citrus rootstocks grown on two substrates and kept in different containers at the stage of sowing irrigated by capillarity. Two commercial substrates were tested and seeding was performed in three containers: stiff plastic tubes with 50cm3, stiff plastic tubes with 120cm3 and polystyrene trays containing 72 cells with a volume of 120cm3. The six rootstocks citrus evaluated were: Trifoliata [Poncirus trifoliata [L.] Raf.]; Flying Dragon [Poncirus trifoliata (L.) Raf. var. monstrosa]; Volkameriano lemon (Citrus volkameriana Pasq.), Fepagro C37 citrange [P. trifoliata x Citrus sinensis [L.] Osbeck.], Sunki tangerine (C. sunki hort. ex Tan.) and Swingle citrumelo (P. trifoliata x C. paradisi). The emergence, height and diameter of plants in the greenhouse were evaluated. Fresh weight, root and shoot dry weight, leaf number, leaf area per plant and leaf area per leaf were evaluated in the laboratory. In the evaluations of emergence of seedlings, the Sunki tangerine, Volkameriano lemon and Swingle citrumelo had higher rates compared to Trifoliata, Fepagro C37 citrange and Flying Dragon. When the system in a floating irrigation system, commercial substrate 1 is recommended for all containers. The commercial substrate 2 should be only used in alveolate trays of 120cm3.

Interação entre porta-enxertos de citros e fungos micorrízicos arbusculares

Arbuscular mycorrhizal fungi (AMF) support plant development, however, symbiosis depends on species of both symbionts. This study aimed to evaluate the interaction between rootstock citrus inoculated with species of arbuscular mycorrhizal fungi. Three rootstocks citrange ‘Fepagro C37 Reck’ [ Poncirus trifoliata (L.) Raf. x Citrus sinensis (L.) Osbeck.], ‘Hong-Kong’ kumquat ( Fortunella hindsii Swingle) and ‘Trifoliata’ ( Poncirus trifoliate ) were tested, inoculated with two species of AMF ( Glomus etunicatum W.N. Becker & Gerd.and Acaulospora sp. ) and a treatment not inoculated. We evaluated the height (cm), stem diameter (mm), leaf area (cm² / plant), leaf number, fresh and dry root and shoot weight (g), the level of reserves in tissues and the colonization of AMF in the roots. The species G. etunicatum and Acaulospora sp . colonized the roots of rootstocks, but they were only eff ective for ‘Fepagro C37 Reck’. Poncirus trifoliata had the highest vigor in the absence of AMF.