No abstract

Propagation by cuttings is an alternative for obtaining citrus rootstocks. The exogenous application of indolebutyric acid (IBA), cutting collection season and genotypes used may affect the rooting and vegetative growth of citrus rootstocks cuttings. Two experiments were conducted to study the influence of these factors. In the first one, semi-hardwood cuttings from the 'Sunki' mandarin hybrids H49 and H77 were collected in the fall and late spring of 2013 and treated with IBA (0 mg L-1, 1,500 mg L-1 and 3,000 mg L-1). For each collection season, a 2 x 3 (two genotypes x three IBA concentrations) factorial scheme was adopted, in a randomized blocks design. In the second experiment, the development of cuttings that rooted in the late spring was evaluated until grafting. In this case, a completely randomized experimental design was adopted, with the hybrids H49 and H77. The IBA treatments positively influenced rooting and number of roots only in the fall collection, peaking at 23.3 % of rooted cuttings. In the late spring collection, rooting was close to 100 %, with the IBA treatment being unnecessary. Around 50 % of cuttings from the 'Sunki' mandarin hybrids were ready for grafting at 14 months after cutting.

ResumoSubstratos, idade de mudas e ambientes no crescimento inicial de Cariniana pyriformis Miers. A produção massal de mudas de alta qualidade pode melhorar os planos de conservação e reflorestamento do mogno colombiano (Cariniana pyriformis Miers), uma espécie florestal nativa da Colômbia. Para contribuir com esse objetivo, dois ambientes foram avaliados. O primeiro, constituído de uma casa de vegetação em arco com cobertura plástica antitérmica, 50% de sombreamento e fotosseletivo à radiação U.V, enquanto o segundo de um viveiro agrícola coberto com tela preta de monofilamento e 65% de sombreamento. Para cada ambiente adotou-se um delineamento experimental de blocos completoscasualizados em esquema de parcelas divididas. A parcela principal correspondeu a cinco substratos com diferentes formulações volumétricas de areia (SA), casca de pinus (PB), fibra de coco (CF), composto comercial obtido a partir da compostagem de estrume de aves, pó de cana-de-açúcar e pó de serragem (CC) e subsolo da região (SS). A subparcela correspondeu a duas idades das mudas: 77 e 95 dias após a semeadura. Os valores para o índice de qualidade de Dickson, área foliar, massa seca da parte aérea e do sistema radicular para ambas idades foram maiores quando cultivadas em casa de vegetação. Dentro do viveiro agrícola não houve efeito dos substratos. Para ambos ambientes e idades, atributos morfológicos ótimos não foram atingidos nas mudas para seu estabelecimento em campo. O substrato à base de 20% SA + 20% CC e 60% SS é o mais indicado pois aumenta o vigor das mudas, seguido pela composição de 20% PB + 20% CC + 60% SS. Palavras-chaves: mogno colombiano, índice de qualidade de Dickson, ambiente protegido, Lecythidaceae.

Plantulas de tomate.Foto: Álvarez-Herrera.Aplicación líquida edáfica y foliar de manganeso en espinaca (Spinacia oleraceae L.) cultivada en sustrato vermicompost Foliar and soil application of manganese in spinach (Spinacia oleraceae L.) grown in a vermicompost substrate Plántulas de espinaca híbrido Panther. Foto: A.I. Prato RESUMENEn la agricultura orgánica de hortalizas, el uso de sustratos a base de vermicompost es una alternativa cada vez con mayor aceptación. La fertilización eficiente de manganeso (Mn) requiere manejos agronómicos diferenciados dadas las complejas variables de absorción y disponibilidad de este micronutriente en el suelo. Nuevos productos de fertilizantes deben ser estudiados extensamente. Se evaluó en condiciones de invernadero, el efecto de la fertilización de Mn en espinaca, híbrido Panther, empleando dos fuentes -sulfato y gluconato-en aplicación líquida edáfica y foliar, a una concentración de 50 mg L -1 (1,5 kg ha -¹), y sin la aplicación del micronutriente. La fertilización fue parcializada en 10 aplicaciones. Plántulas con 15 días desde germinación fueron trasplantadas en materas de 2 L en un sustrato vermicompost. Desde los 12 días después de iniciar los tratamientos, las plantas evidenciaron efecto según la fuente y método de aplicación para la masa seca aérea y área foliar. Al final del periodo de estudio, la fuente de MnSO 4 edáfico presentó la mejor respuesta, con mayor acumulación de masa seca aérea, número de hojas y altura planta frente a las plantas control, 86,7; 56,8 y 28,0%, respectivamente. Tanto la aplicación foliar y edáfica del gluconato de Mn resultaron en valores próximos, sin síntomas visibles de toxicidad a la dosis evaluada. Este producto podría llegar a ser una opción viable de fertilización de Mn en espinaca. Additional key words: complex micronutrient, fertilization, dry mass, plant height. Fecha de recepción: 21-07-2014Aprobado para publicación: 10-11-2014 ABSTRACTIn the organic farming of vegetables, the use of vermicompost-based substrates is an alternative with increasing acceptance. Efficient fertilization with manganese (Mn) requires different agricultural management variables given the complex variables of absorption and availability of this micronutrient in the soil. New fertilizer products must be studied extensively. The effects of Mn fertilization on spinach were evaluated under greenhouse conditions using two sources -sulfate and gluconate -in liquid foliar and soil applications at a concentration of 50 mg L -1 (1.5 kg ha -1 ) and without the application of this micronutrient. The fertilization was separated into ten applications. Fifteen days after germination, seedlings were transplanted into 2 L pots filled with a vermicompost substrate. Starting at 12 days after the beginning of the treatment, the plants showed effects that depended on the source and method of the application for the aerial dry mass and leaf area. By the end of the study period, the edaphic source of MnSO 4 presented the best response with a higher dry matter, number of leav...

Seedling emergence is the main propagation method of forest species. Thus, we aimed to evaluate emergence aspects of the tree legume Clathrotropis brunnea Amshoff (sapán or blackheart sapán), a Fabaceae of high economic value endemic to the Colombian rainforest. We characterized the biometry of legumes and seeds and assessed seedling emergence in three experiments: (1) effect of fruit color and substrate, (2) seed conservation in storage, and (3) presoaking and seed position. Our results showed that seeds of green-yellow fruits have greater length and weight and a water content of up to 53%. Seedling emergence did not differ between green-yellow and dark-brown fruits but did differ with substrate type; nearly 80% of seedlings emerged in the sand substrate (S1), but only 62% emerged in the mixed substrate (S3). Fresh sapán seeds are nondormant, showing a recalcitrant behavior in which seedling emergence decreased after storage in all tested conditions. Both seed-sowing positions allowed an emergence of >80% with a small benefit of the hilum downward, regardless of presoaking treatments. However, these differences did not affect seedling height or biomass after emergence. Our results provide basic knowledge on production of tropical seedlings, seeking species conservation, and use in restoration projects. Study Implications Our study provides information on seedling emergence of a legume tree endemic to the Colombian rainforest, Clathrotropis brunnea Amshoff. Because the species has a high economic value, it has been overexploited in the Middle Magdalena Valley. We have found that C. brunnea seeds are not dormant, and thus fresh seeds could easily germinate and form seedlings in the nursery, but such seeds are sensitive to desiccation during storage (recalcitrant). Therefore, other factors such as deforestation and climatic changes may threaten its regeneration from seeds and propagation techniques are urgently needed for its conservation.

RESUMEN -los patrones se obtienen tradicionalmente en la citricultura a partir de semillas, seleccionándose las plantas de origen apomíctica. Sin embargo, hay riesgo de no realizarse la selección correcta, debido a la baja apomixis y la alta heterocigocidad en algunas especies o cultivares, como el mandarino 'Sunki'. la obtención de los mismos por estaquillas solucionaría el problema. el objetivo de este trabajo fue evaluar el potencial de enraizamiento de estaquillas del mandarino 'Sunki' (Citrus sunki hort. ex tan.), colectadas de matrices cultivadas en el campo o en ambiente protegido, utilizándose diferentes concentraciones del ácido indolbutírico (AIB). Las estaquillas se colectaron en el final de la primavera y se mantuvieron por 90 días en cámara de nebulización intermitente. Se adoptó el diseño experimental de bloques completos al azar, con cuatro repeticiones, en arreglo factorial 2 x 4, referente a dos condiciones de cultivo (matrices cultivadas en campo y en ambiente protegido) y cuatro concentraciones del AIB (0, 750, 1.500 y 3.000 mg l -1 ). el enraizamiento del mandarino 'Sunki' fue elevado, alcanzando el 96% en las dos condiciones. la brotación (54%) y la supervivencia (95%) de las estacas presentaron valores satisfactorios, independientemente del AIB. el empleo del AIB solamente es necesario en estacas provenientes de plantas mantenidas en el ambiente protegido, puesto que mejora su enraizamiento y el número de raíces. Palabras-clave: Citrus sunki, enraizamiento, fitorregulador, patrón GROwING CONDITIONS Of ThE MOThER PLANT AND USE Of IBA IN ThE PROPAGATION Of 'SUNKI' MANDARIN BY CUTTINGSABSTRACT -citrus rootstocks are obtained from seeds, selecting the apomitic seedlings. however, there is risk of not making the correct selection, due to low level of polyembryony and high heterozygosity in some species or cultivars, such as 'Sunki' mandarin. therefore, obtaining the citrus rootstocks through cuttings may solve the problem. the objective of this study was to evaluate the potential of rooting semi-hardwood cuttings of 'Sunki' mandarin (Citrus sunki Hort. ex Tan), collected from mother plants cultivated on the field or in a greenhouse, using different concentrations of indolbutyric acid (IBA). cuttings were collected in late spring and maintained for 90 days under greenhouse mist system. completely randomized block design was used, with four replications in a factorial 2 x 4, concerning to two culture conditions (mother plants cultivated on the field and in a greenhouse) and four concentrations of IBA (0, 750, 1.500 and 3.000 mg L -1 ). the rooting of 'Sunki' mandarin was high, reaching 96% in both conditions of culture. the sprouting (53%) and survival (95%) of the cuttings showed satisfactory values, regardless of the IBA. the use of IBA is only necessary in cuttings originated from plants kept in greenhouse, improving rooting and number of roots. Index-terms: Citrus sunki, growth regulators, rooting, rootstocks.1 (trabalho 025-15 INTRODUCCIÓNen la citricultura, los patrones se propagan por semi...

Cariniana pyriformis es una arbórea nativa de Colombia con elevado potencial en plantaciones puras y sistemas agroforestales de Theobroma cacao. En vivero agrícola con cobertura plástica, se evaluaron la producción y calidad de plántulas con un diseño de bloques completos al azar y tres repeticiones empleando tres contenedores plásticos (tratamientos): bolsa (1700 cm3), bandeja portatubete (700 cm3) y bandeja multicelda (650 cm3). Entre los 120 (bolsa) y 137 (bandeja portatubete) días después de siembra (dds), las plántulas alcanzaron los 25 cm de altura y 3 mm de diámetro de cuello. El peso seco de la parte área (p= 0,0179) y peso seco del sistema radicular (p=0,0327) de las plántulas a los 160 dds fueron superiores en la bolsa en comparación con las plántulas crecidas en la bandeja portatubete. En paralelo, la producción de plántulas de C. pyriformis en bandeja multicelda presentó índices de calidad muy similares a la bolsa, pero con una reducción en el costo por plántula entorno al 60%.

Cariniana pyriformis shows a higher variability in fresh mass per fruit (35%).One kilogram corresponds to 6715 seeds with 11% humidity.The application of GA 3 allows accelerating and synchronizing seedling emergence.