POSTHARVEST QUALITY OF FEIJOA FLOWERS TREATED WITH DIFFERENT PRESERVATIVE SOLUTIONS AND 1-METHYLCYCLOPROPENE Translated title: QUALIDADE PÓS-COLHEITA DE FLORES DE GOIABEIRA-SERRANA TRATADAS COM SOLUÇÕES CONSERVANTES E 1-METILCICLOPROPENO

Abstract

ABSTRACT This study was carried out to assess the postharvest quality preservation of feijoa(Acca sellowiana Berg) flowers in response to treatments with different preservative solutions and 1-methylcyclopropene (1-MCP). Recently opened feijoa flowers were harvested in the morning (between 8h and 10h) and immediately after pulsed with preservative solutions of salicylic acid, ascorbic acid and sucrose, all at doses of 0 (control), 2, 5 or 10%, and treated with 1-MCP at doses of 0 (control), 250, 500 or 1,000 nL L-1. Each trial with preservative solutions or 1-MCP treatment was a distinct experiment conducted in a completely randomized design with four replicates, each replicate with four flowers. After the treatment, the flowers were stored for 12 days at 10±1 oC and 85±5% RH. At every two-days intervals the flower petals were visually evaluated for wilting and darkening according to a hedonic scale varying from 1 (less intense) to 5 (more intense). Petal color was ranked from 1 (intense pink) to 5 (white). The 1-MCP at 500 nL L-1 and the salicylic acid (regardless of the dose) delayed the changes of petal color for up to eight and six days of storage, respectively. Flowers treated with salicylic acid, 1-MCP or ascorbic acid had a more substantial delay in petal wilting. Flowers treated with salicylic acid had wilting rank of 2 after six days of storage when treated with doses of 5% or 10%, and after eight days when treated with the dose of 2%, while flowers treated with 1-MCP at 500 and 1,000 nL L-1 and ascorbic acid at 2% and 5% had wilting rank of 2 after four days of storage. The most substantial delay of petal darkening (until the fourth day of storage) was achieved with 1-MCP at 500 nL L-1.

Translated abstract

RESUMO O objetivo deste trabalho foi avaliar a manutenção da qualidade pós-colheita de flores de goiabeira-serrana (Acca sellowiana Berg), em resposta ao tratamentocom soluções conservantes e 1-metilciclopropeno (1-MCP). As flores recém-abertas de goiabeira-serrana foram colhidas no início da manhã (entre 8 e 10 h) e submetidas a “pulsing” com soluções conservantes de ácido salicílico, ácido ascórbico e sacarose, todas nas doses de 0 (testemunha), 2, 5 e 10%, e aplicação de 1-MCP nas doses de 0 (testemunha), 250; 500 e 1.000 nL L-1. Cada ensaio com solução conservante ou de tratamento com 1-MCP consistiu em experimento distinto, segundo delineamento experimental inteiramente casualizado, com quatro repetições, cada repetição com quatro flores. Após o tratamento, as flores foram armazenadas durante 12 dias a 10±1 oC e 85±5% UR, e as pétalas avaliadas visualmente, em intervalos de dois dias, quanto a murcha e escurecimento, em uma escala de 1 (pouco acentuado) a 5 (muito acentuado), e de cor, numa escala de 1 (rosa intenso) a 5 (branco). O 1-MCP na dose de 500 nL L-1 e o ácido salicílico, independentemente da dose, prolongaram a manutenção da cor das pétalas por oito e seis dias de armazenamento, respectivamente. A murcha das pétalas também foi menor nos tratamentos com ácido salicílico, 1-MCP ou ácido ascórbico; flores tratadas com ácido salicílico passaram para 2 na escala evolutiva, no sexto dia nas doses de 5 e 10%, e no oitavo dia na dose de 2%; enquanto em flores tratadas com 1-MCP nas doses de 500 e 1.000 nL L-1 e ácido ascórbico nas doses de 2 e 5%, isto ocorreu no quarto dia de armazenamento. O maior retardo no escurecimento das pétalas (até o quarto dia de armazenamento) foi obtido com 500 nL L-1 de 1-MCP.