Refrigerated storage period of Rhizophores for Yacon propagation / Períodos de armazenamento refrigerado de rizóforos para propagação de yacon

ABSTRACT

The yacon plant produces tuberous roots, used mostly for fresh consumption. This crop is propagated primarily via vegetative structures, called rhizophores. However, since these propagules have short periods of viability after harvest, storing them in cold chamber conditions may be a viable alternative to optimize yacon seedling production. The objective of this study was to test the effect of the refrigerated storage period of yacon rhizophores on seedling development. The experimental design was completely randomized, with eight replications, containing 30 useful plants per replication. Treatments were cold storage periods of propagative materials (35, 28, 21, 14, and 7 days) and a control (planting without storage). The results show that keeping rhizophores in cold storage under temperatures of 8 ºC (± 2 ºC) for a period between 21 to 35 days improves sprouting rates (speed and vigorousness), reducing seedling mortality and favoring initial yacon growth. The refrigerated storage for 21 and 35 days proved to be an alternative to achieve improved plant stand in production fields, reflecting in more uniform harvest, and minimizing the problem of seasonal availability of propagative material.Yacon, is known for its tuberous roots, which are consumed as functional food and is propagated mostly in the vegetative form, via propagules, so-called rhizophores. However, they are organs with little durability in its propagation form. Storing them in cold chamber conditions, can be a viable alternative for the seedlings production of the culture. The objective of this study was to verify the influence of the refrigerated storage period of yacon rhizophores in the initial plant development. The experimental design was completely randomized with eight replicates and six treatments and the rhizophores were place in the refrigerated storage for: 7, 14, 21, 28 and 35 days; and time zero (planting without storage). The results show that the rhizophores in the refrigerated storage in a temperature of 8 to 10°C, for a period between 21 to 35 days had better sprouting rate (speed and vigor), reducing mortality, which favored the initial yacon growth. The refrigerated storage between 21 and 35 days showed to be an alternative that resulted in a uniform plant stand in crops, also reflecting the uniformity in the harvest, and minimizes the problem of seasonality offering culture propagation material.

RESUMO

A yacon, conhecida por suas raízes tuberosas, que são consumidas como alimento funcional, é propagada em sua maioria na forma vegetativa, via propágulos, assim chamados de rizóforos. No entanto, são órgãos de pouca durabilidade na sua forma propagativa. Logo, o armazenamento dos mesmos em condições de câmara fria, pode vir a ser uma alternativa viável para a produção de mudas da cultura. Assim, objetivou-se com o presente trabalho, verificar a influência do período de armazenamento refrigerado dos rizóforos de yacon no desenvolvimento inicial das plantas. O delineamento experimental foi inteiramente casualizado com oito repetições e seis tratamentos constituídos pelos períodos de armazenamento refrigerado em que os rizóforos foram submetidos: 7, 14, 21, 28 e 35 dias; e o tempo zero (plantio sem armazenamento). Os resultados demonstraram que o armazenamento refrigerado dos rizóforos, em temperatura de 8 a 10 ºC, por um período entre 21 a 35 dias, proporcionou melhores índices de brotação (velocidade e vigorosidade), diminuindo a taxa de mortalidade, o que favoreceu o crescimento inicial da yacon. O armazenamento refrigerado entre 21 e 35 dias apresentou ser uma alternativa que resultou em maior uniformidade na formação do estande de plantas na lavoura, inclusive repercutindo na uniformidade de colheita, além de minimizar o problema de sazonalidade da oferta de material propagativo da cultura.