Postharvest conservation of Formosa 'Tainung 1' papaya under refrigeration, modified atmosphere, and chitosan

The objective of this work is to evaluate the use of modified atmosphere and chitosan as an alternative to chemical treatment in postharvest conservation of 'Tainung 1' papaya under refrigeration. The experiment comprised of completely randomized blocks with four replications, one fruit per replication, with a 2 × 4 × 4 factorial design as follows: two types of packaging (with or without polyvinyl chloride [PVC] stretchable film, thickness of 17 µm), four treatments (control, 2% chitosan, 4% chitosan, and prochloraz fungicide with 33.75 g a.i.·100 L­1), and four storage periods (0, 7, 14, and 21 days) at 10 °C and relative humidity (RH) of 90 ± 5%. The variables evaluated were mass loss (ML), external appearance, titratable acidity (TA), soluble solids (SS), vitamin C, reducing sugars (RS), and total sugars (TS). The storage of 'Formosa' papaya under refrigeration at 10 °C and RH of 90 ± 5% associated with PVC provided a low percentage of ML and longer conservation time of apparent quality (up to 7 days) in relation to fruits with no storage in PVC. The external appearance of fruits was preserved for up to 14 days by the PVC + 4% chitosan treatment and for up to 21 days by the PVC + prochloraz fungicide treatment. The treatment PVC + 4% chitosan associated with refrigeration is efficient in maintaining fruit quality. It is, for up to 14 days, a viable alternative to the use of prochloraz fungicide for postharvest conservation of 'Formosa' papaya.

In vitro antimicrobial activity and alternative control of anthracnose in papaya / Atividade antimicrobiana in vitro e controle alternativo da antracnose em mamão

We evaluated the efficacy of natural products in the control of papaya anthracnose, in vitro and in vivo. The in vitro experiments for evaluation of mycelial growth used a completely randomized 10 × 4 factorial design (treatments × evaluation periods) with eight replicates, with sporulation evaluated at the end of the experiment. The treatments involved the use of aqueous extract at concentrations of 5 and 15% for Syzygium aromaticum (L.) Merr. & Perry (clove), Cinnamomum zeylanicum Breym (cinnamon), and Zingiber officinalis Rox. (ginger); 1 and 3% chitosan; the fungicide Prochloraz at 100 µg.mL-1; and a control (no treatment). For evaluating conidia germination, we used six treatments with five replicates. The treatments included 7.5% of each extract (clove, cinnamon, and ginger), 1.5% chitosan, and 50 µg.mL-1 of Prochloraz. For the in vivo experiment, "Formosa" papaya "Tainung 1" was used in a completely randomized design, with six treatments and four replicates to evaluate the severity of anthracnose caused by Colletotrichum gloeosporioides. The fruits were treated by immersion for 5 min with 15% clove, cinnamon, and ginger extracts, 8% chitosan, and control with distilled water, and immersion for 2 min in Prochloraz (33.75 g a.i./100 L). The treatments with 15% clove extract and 8% chitosan were effective in all evaluations, resulting in a viable alternative to the fungicide Prochloraz. The treatments with ginger extract were less effective and those with cinnamon offered intermediate control.(AU)

Este trabalho teve por objetivo avaliar, in vitro e in vivo, a eficácia de produtos naturais no controle da antracnose do mamão. Os experimentos in vitro foram instalados em delineamento inteiramente casualizado, sendo para a avaliação de crescimento micelial considerado o esquema fatorial 10 × 4 (tratamentos x períodos de avaliação) com oito repetições, com a esporulação avaliada ao final do experimento. Os tratamentos utilizados foram: extrato aquoso nas concentrações de 5 e 15% de Syzygium aromaticum (L.) Merr. & Perry (cravo-da-índia), Cinnamomum zeylanicum Breym (canela) e Zingiber officinalis Rox (gengibre), quitosana 1 e 3%, fungicida Procloraz a 100 µg.mL-1 e testemunha (sem tratamento). Para a avaliação da germinação de conídios, foram considerados seis tratamentos com cinco repetições. Foram utilizados os mesmos tratamentos, porém, nas concentrações de 7,5% de cada extrato (cravo-da-índia, canela e gengibre), 1,5% de quitosana, e 50 µg.mL-1 de Procloraz. Para o experimento in vivo, foram utilizados mamões "Formosa" "Tainung 1", em delineamento inteiramente casualizado, sendo seis tratamentos com quatro repetições para avaliação de severidade de antracnose causada por Colletotrichum gloeosporioides. Os frutos foram tratados por imersão durante 5 minutos com extratos de cravo-da-índia, canela e gengibre a 15%, quitosana a 8% e testemunha com água destilada, e imersão por 2 minutos em fungicida Procloraz (33,75 g i.a./100 L). Os tratamentos com extrato de cravo-da-índia a 15% e quitosana a 8% foram eficazes em todas as avaliações, sendo uma alternativa viável ao fungicida Procloraz. Os tratamentos com extrato de gengibre foram menos eficientes, com controle intermediário para o extrato de canela.(AU)