Bud source, asepsis and benzylaminopurine (BAP) effect on yacon (Polymnia sonchifolia) micropropagation

The yacon (Polymnia sonchifolia) is used largely for the high fructan content of its tubers; consequently, it is a good alternative for diabetics. One of the more important restricting factors of the commercial production of yacon is its susceptibility to nematode attack. This, as well as germplasm bank maintenance, justifies the importance of in vitro propagation of this species. In this way, our work aimed to verify the best asepsis method for yacon for the in vitro establishment from the rhizophore and the axillary buds of the aerial parts, and the effect of benzylaminopurine (BAP) addition to the culture medium. The number of contaminated cultures, the occurrence of phenolic oxidation and the occurrence of a vitreous aspect, showed differences with bud source, immersion time for asepsis, and BAP use. The results contribute to establishing a yacon micro propagation procedure

Desempenho de cultivares nacionais de batata para produtividade de tubérculos.

O objetivo deste trabalho foi verificar o desempenho dos cultivares de batata nacionais BRS Ana e BRS Clara, em comparação com os cultivares importados Ágata e Asterix, em relação à produtividade de tubérculos. Os experimentos foram realizados no município de Canoinhas, SC. Foram avaliados quatro cultivares de batata: BRS Ana, BRS Clara, Asterix e Ágata. O delineamento experimental foi em blocos casualizados, com quatro repetições. As parcelas continham quatro linhas com 20 plantas em cada linha. Cento e dez dias após o plantio foi realizada a colheita e, os tubérculos de cada parcela, avaliados para caracteres relacionados com a produtividade de tubérculos. Os dados foram submetidos à análise de variância e agrupamento de médias, por Skott & Knott, a 5% de probabilidade. Os cultivares de batata nacionais BRS Ana e BRS Clara foram mais produtivos do que os importados Asterix e Ágata; no entanto, são mais tardios, quanto ao ciclo vegetativo

Aphid species and population dynamics associated with strawberry.

Aphids are among the major pests associated with strawberries in Southern Brasil. In this study, we identified the main species that occur in strawberry fields in the states of Paraná and Rio Grande do Sul, Brasil. We also compared the effectiveness of different sampling methods and studied the population dynamics of aphid species during two strawberry crop cycles in the municipality of Pinhais, state of Paraná, Brasil. Chaetosiphon fragaefolii (Cockerell) and Aphis forbesi Weed were the main species associated with strawberry. The method of hit plant and the Möericke trap showed equal effectiveness to capture wingless and winged insects. The peak population of aphids in the state of Paraná occurred from September to November. This information can help producers to implement strategies to monitor and control the major aphid species that occur in strawberry culture