Blackberry Crops Research Articles

Incidence and Distribution of Viruses in Blackberry (Rubus sp.) in Alabama

A survey was conducted in 2007 to determine the incidence and distribution of viruses in commercial blackberry crops in Alabama. Symptomatic and asymptomatic plants in eight major blackberry producing counties were tested for Impatiens necrotic spot virus, Raspberry bushy dwarf virus, Tobacco ringspot virus, and Tomato ringspot virus using enzyme-linked immunosorbent assay. Seventy-nine percent of the blackberry samples were infected. Tomato ringspot virus was detected in 45% of the samples, followed by Impatiens necrotic spot virus (35%), Tobacco ringspot virus (31%), and Raspberry bushy dwarf virus (26%). Each virus was detected in each of the eight counties surveyed and in each of the 14 blackberry cultivars evaluated in this study. Seventy-eight percent of the asymptomatic blackberry samples tested positive for virus infection, an indication that symptom expression is not necessarily a reliable diagnostic method for virus infection of blackberries.

Custo de produção de amora-preta em região tropical

O cultivo da amora-preta é recente no Brasil. A espécie apresenta elevada adaptabilidade, baixa exigência em frio, facilidade de manejo, rusticidade e pouca utilização de defensivos agrícolas. É uma fruta que vem despertando elevada atenção dos consumidores devido à presença de compostos fenólicos com propriedades antioxidantes. Com este trabalho, objetivou-se analisar o custo de produção do cultivo da amora-preta, em primeiro ano de produção. Para estimar a matriz de coeficientes técnicos e os custos de produção, em 2007, os preços de venda foram levantados junto a um produtor, e o restante das informações foi obtido de um experimento. De acordo com os dados e os cálculos de custos, a primeira produção da cultura foi de 3.000 kg.ha-1, com custo de implantação e condução, no primeiro ano, de R$ 8.710,63, e no segundo ano, apresentou custo de R$ 6.467,50. o custo de produção foi relativamente baixo comparado com outras frutíferas perenes cultivadas na região, evidenciando que esta atividade pode ser mais uma alternativa de renda para agricultura familiar.

Identificación y caracterización preliminar del agente causal de la mancha necrótica de las hojas de la mora (Rubus glaucus) en el muncipio de Trujillo (Valle del Cauca, Colombia)

El cultivo de la mora en las veredas Chuscales y Monteloro del municipio de Trujillo (Valle del Cauca) genera el 100% de los ingresos familiares. Con el objeto de mejorar la productividad y beneficiar la economía de estas comunidades, a lo largo de dos años se llevó a cabo un proyecto de diagnóstico y desarrollo de prácticas agronómicas y manejo sanitario, en arreglos agroforestales en el cultivo de la mora. Con frecuencia se hallaron manchas necróticas en el follaje que no correspondían a síntomas de enfermedades descritas previamente; éstas coalescían hasta cubrir totalmente el área foliar y necrosar la hoja; además, se observó desintegración de los tejidos en presencia de alta humedad. En campo se encontró una incidencia del 30% aunque no se evaluaron los efectos sobre la producción. En laboratorio, mediante cultivo en medios selectivos, pruebas bioquímicas e identificación morfológica, se determinó la presencia de Pseudomonas no fluorescentes procedentes de muestras de hojas de mora de diferentes edades con lesiones necróticas. Así mismo, se realizaron pruebas de patogenicidad en invernadero y laboratorio utilizando una concentración de 108 bacterias/mL y agua destilada estéril para los testigos, procedimiento que logró reproducir las lesiones encontradas en campo y que permitió reaislar de nuevo la bacteria.

EPIDEMIOLOGICAL STUDIES ON RUBUS STUNT (RS) IN BLACKBERRY ORCHARDS LOCATED NEAR TRENTO (ITALY)

Rubus stunt phytoplasma (RS), a member of the elm yellows phytoplasma group, is widespread in Rubus in continental Europe. The recent introduction of new berry cultivars in Trento province (Northern Italy) prompted us to obtain more information about the spreading of RS and other phytoplasmas in these crops. In late spring/summer 2002 field observations were carried out in different commercial berry fruit crops and in related wild species. Rubus stunt-like symptoms were observed only in few plants of Rubus spinosa cv. Topee and in almost the 43 % of plants in a blackberry crop of 'Lochness' located in the Adige valley. The predominant symptoms observed on these two-three years old plants have been virescence, phyllody and other severe flower and fruit anomalies. Stunted growth, short internodes, few canes, proliferation of shoots from the base and leaf reddening in early autumn were also common. RS has been reported to be spread mainly by leafhoppers (Macropsis sp.). Chromotropic traps used in the crops did not permit captures of individuals of Macropsis spp; Macrosteles cristatus, the largest leafhopper collected, was analysed. The results confirmed a strict association between the symptoms and the detection of RS phytoplasma; no other phytoplasmas were found. PCR and nested-PCR also failed to detect phytoplasmas in the symptomless plants and in all Macrosteles groups tested. Rubus stunt is not widespread in the Trento province and Macropsis fuscula hasn’t been found; therefore vegetative propagation might have contributed to the dissemination of this pathogen. For this reason epidemiological studies are in progress, also on wild blackberries, to detect and eliminate sources of infection.

AMORA-PRETA: NOVA OPÇÃO DE CULTIVO NO BRASIL

A amoreira-preta é uma frutífera de grande potencial para as regiões brasileiras com período de inverno marcante e propícia para pequenas propriedades agrícolas. Os frutos podem ser utilizados para consumo in natura e para produção de geleificados e doces caseiros, sendo assim, potencial para as famílias que trabalham com o ecoturismo regional. Além destas características, praticamente não necessita de insumos químicos, sendo ótima opção para o cultivo orgânico, além das propriedades nutricionais e medicinais dos frutos.

Arthropod pests ofRubusin Europe: Pest status, current and future control strategies

SummaryArthropod pests of raspberry (Rubus idaeus L.), cultivated blackberry (R. laciniatus Willd., R. procerus P. J. Mull.) and Rubus hybrids, e.g. Tayberry and Loganberry in Europe are reviewed and economic damage and chemical and cultural control strategies described. Particular consideration is given to the most damaging pests, including aphids (Amphorophora idaei (Borner) and Aphis idaei van der Goot), raspberry beetle (Byturus tomentosus Degeer), clay-coloured weevil (Otiorhynchus singularis L.), raspberry cane midge (Resseliella theobaldi (Barnes)), raspberry moth (Lampronia rubiella (Bjerkander)) and two-spotted spider mite (Tetranychus urticae Koch.). New pest species or biotypes continue to be discovered on Rubus, as a result of changes in pesticide usage, the cultivation of new varieties, or insect-host range, e.g. Graphiphora augur (Fabr.), Cantharis obscura L. and Agrilus aurichalceus Redt. The potential entomological problems associated with protected cultivation, pesticide usage and application in cane fruit crops are considered. Many of the most important pest species attacking cultivated Rubus in Europe are host specialists. Novel stategies for their control are discussed, based on defence chemicals found in Rubus leaves and canes, and the use of biotechnology to enhance resistance. Mechanical harvesting of cane fruit is increasing in importance, and fruit harvested by machine may be contaminated by a range of arthropods which require additional control measures. The withdrawal from use of existing pesticides and the increasing public demand for the production of fruit without pesticides are considered as powerful external pressures determining the future direction of crop protection in raspberry and blackberry crops. The prospects for developing Integrated Pest Management systems for cane fruit crops are discussed in relation to biological, technical and socio-economic factors.