Huertos y paseos de la Valencia barroca y neoclásica

Esta disertación tiene como marco histórico el proceso de transición de una mentalidad impregnada todavía por el renacimiento a otra de perfiles ilustrados clasicistas que tuvo su expresión en la arquitectura academicista de la segunda mitad del siglo XVIII, pero que no impregnó el arte jardinero en Valencia, consolidado estilísticamente en los acompañamientos verdes de las moradas de los miembros de los diferentes estamentos: virreyes, nobleza urbana, nobleza rural, gremios, conventos, monasterios y paseos públicos. En Valencia, como en otras regiones valencianas, había sido el barroco-mudéjar, según expresión de Fernando Chueca, y no un barroco de concepción estructural, el que se había desarrollado desde finales de siglo XVII. Este barroco decorativo, plástico, alcanzó en Valencia durante la primera mitad del siglo XVIII y a través de breves contactos con lo italiano, un porte culto y refinado

Producción Industrial de Palmeras en Contenedor para Jardín

En las dos últimas centurias y sobre todo en el presente siglo -con especial importancia en los últimos veinte años- ha nacido una fuerte corriente comercial que ha promovido una industria viverística muy estimable, dedicada a la producción de palmeras. La causa estriba en la belleza de estas plantas y la sensación de jardín tropical que producen, unido al gusto actual por ciertos clichés con imágenes exóticas. Por otro lado, en los últimos lustros se ha producido una gran demanda de palmeros jóvenes -de dos a cuatro años desde semilla- cultivadas en contenedores de 14, 17 y hasta 30 cm. de diámetro, para ser utilizadas en diversos países centroeuropeos como plantas de interior. Estas circunstancias han generado una potente industria viverística basada en la aplicación de las nuevas técnicas de cultivo industrial de planta en contenedor. Asimismo, la viverística de plantas se revela como herramienta necesaria para la regeneración de zonas de palmeras con alto valor ecológico. Las palmeras constituyen uno de los principales grupos de interés ornamental y se integran en un conjunto de familias que abarcan unas 2800 especies. Su importancia ha sido notable en la historia y sobre todo en la antigüedad. Cinco géneros de palmeras (Howea, Chamaedorea, Chrysalidocarpus, Cocos y Phoenix) se encuentran entre las 50 plantas más vendidas en Holanda. Las palmeras pertenecen al orden botánico Arecales, (o Principes), que contiene sólo una familia, las Arecaceae (o Palmae)

Detection of a Tristeza-Seedling Yellows Strain in Spain

In late 1984, some growers were found to be using budwood of a very early maturing satsuma mandarin of uncertain origin, for topworking citrus orchards near Valencia. Indexing of this material showed that it was infected with a very severe strain of citrus tristeza virus (CTV). It induced severe stunting, stem pitting, vein clearing and vein corking in Mexican lime and C. macrophylla; conspicuous stunting and seedling-yellows on Eureka lemon and Duncan grapefruit and stem pitting on sweet orange, grapefruit arid rough lemon. None of the common CTV strains previously studied in Spain induces these severe symptoms. There is some evidence indicating that the original satsuma was illegally introduced from Japan. A program has been established for the eradication of this CTV strain

The Citrus Quarantine Station in Spain

A Citrus Quarantine Station has been recently established in Spain. It is based in a tissue culture procedure developed for safe budwood introduction, consisting of the following steps: a) preliminary budwood inspection; b) budwood disinfestation; c) budwood culture in vitro at 32 C for flushing; d) disinfestation of flushes obtained; e) isolation of 0.1-0.2 mm long shoot tips; f) grafting shoot tips in vitro; g) transplanting micrografted plants to a quarantine greenhouse; h) indexing of micrografted plants; i) release of budwood. Any abnormal or contaminated tissue or plant found during the process and all introduced plant material except the shoot tips are destroyed. Pests, fungi, bacteria and even virus and virus-like diseases introduced with the original material can be easily eliminated by this procedure. The estimated time from budwood introduction until budwood release is 24-30 months, including 18-24 months for xyloporosis indexing

Segregation of Citrus Tristeza Virus Strains Evidenced by Double Stranded RNA (dsRNA) Analysis

A field isolate of citrus tristeza virus (CTV), T-385, was separated from other virus and virus-like diseases by aphid transmission to Mexican lime seedlings. This isolate did not cause decline of sweet orange on sour orange rootstock under field conditions and it induced mild vein clearing and an inconspicuous stem pitting on Mexican lime. Two months after aphid transmission, one of the infected lime seedlings was used as an inoculum source to graft-inoculate 40 citron plants. Two years later, the citron plants were analysed individually for dsRNA content and up to 23 different electrophoretic profiles were found. DsRNA analysis has been repeated three times through the year and the individual patterns remained unchanged. Thirteen of these CTV sub-isolates were graft-transmitted to sweet orange seedlings and the corresponding dsRNA profiles were identical to those previously obtained from citron. All these subisolates induced mild symptoms of Mexican lime similar to those of the original isolate (T-385). These results substantiate that several CTV strains can infect a single citrus plant

Comparative Aphid Transmission of a Common Citrus Tristeza Virus Isolate and a Seedling Yellows Isolate Recently Introduced into Spain

Comparative tests of transmission efficiency have been performed using various aphid species and T-300, an isolate of citrus tristeza virus (CTV) widely distributed in Spain, and T-387 a seedling yellows tristeza isolate (CTV-SY) recently introduced into this country. The aphid species tested were those most abundant on citrus in Spain; Aphis citricola, Toxoptera aurantii, Myzus persicae, and Aphis gossypii. A minimum of 200 aphids were used for each test plant. Sweet orange was used as a donor and Mexican lime as a receptor. Aphis gossypi transmitted T-387 with lower efficiency (60%) than T-300 CTV (90%). A. citricola transmitted the two isolates with a very low efficiency. No transmission was observed with T. aurantii or M. persicae

Persistent Transmission of Citrus Vein Enation Virus by Aphis gossypii and Myzus persicae

Citrus vein enation virus (CVEV) is widely distributed in Spain and circumstantial evidence suggests a high rate of natural spread. No experimental transmission was achievedin extensive trials with several aphid species using a 2-day acquisition period and a 2-day inoculation period. In further experiments, using a 5-7 day acquisition period and a 9-16 day inoculation period, a 95% transmission efficiency was obtained with Aphis gossypii and 10% with Myzus persicae. Furthermore, a 10% transmission efficiency was achieved with viruliferous A. gossypii maintained on healthy plants for a period of up to 14 days after acquisition then given an 11-day inoculation access feed. These results show that CVEV is persistently transmitted by A. gossypii in Spain, thus explaining the high rate of natural spread in the field