Safe postharvest treatments to control botryodiplodia theobromae and botrytis cinerea causing banana finger rots and to maintain fruit quality

Abstract EN

Sodium carbonate and three commercial disinfectants were evaluated as safe alternatives to fungicides to control banana finger rots incited by Botryodiplodia theobromae and Botrytis camera compared with the fungicide Tecto.

The tested disinfectants, i.e.

Barry (hydrogen peroxide / silver ions), Sanosil Super 25 (hydrogen peroxide / silver ions) and Max Guard (sodium dichloroisocynurate) and Sodium carbonate were investigated in vitro against mycelial growth of B.

theobromae and B.

cinerea.

All tested alternative materials completely inhibited the growth of B.

cinerea at the rate of 0.3 %.

Meanwhile, Max Guard, Sanosil Super 25 Bafry and sodium carbonate reduced colony diameter of B.

theobromae by 100, 86.7, 33.3 and 33.3 %, respectively, at the rate of 0.3 %.

Postharvest treatment of banana fruits with Bafry, Sanosil Super 25 and Max Guard and Sodium carbonate at the rates of 0.1, 0.2 and 0.3 % revealed high successive efficacy against tested fungi.

During season 2007, all investigated treatments at 0.3 % gave 100 % efficacy against finger rots except for Bafry which gave 81.1 % efficacy under natural infection conditions.

Next season, in 2008, only Max Guard at 0.3 %) gave 100 % efficacy, while the efficacy of Sanosil Super 25 and Sodium carbonate and Bafry was 93.3, 93.3 and 87.7 %), respectively.

The disinfectants and sodium carbonate tested against B.

cinerea and B.

theobromae on artificially infected bananas achieved high efficiency during seasons 2007 and 2008.

All tested materials at 0.3 % were highly effective against B.

cinerea in both seasons except for sodium carbonate only in season 2007 which achieved fewer efficacies, 43.6 %, comparing with the other treatments.

On the other hand, sodium carbonate at 0.3 % was the most suppressive treatment on B.

theobromae in both seasons, while efficacy of Max Guard was relatively the least.

However, Sanosil Super 25 and Bafry at 0.3 % achieved good control of B.

theobromae comparing with the control, fungicide Tecto which recorded the highest effect its efficiency percentage was 93.3 %.

Generally, all tested disinfectants and sodium carbonate achieved fewer efficacies than tecto in seasons 2007 and 2008, but they achieved high control on both diseases comparing with the control fruits.

On the other hand all the safe compounds studded extended the shelf-life of banana fruits by decreasing weight loss percentage, color transmit ion and maintaining higher values for TSS, acidity and starch at the end of storage maintained fruit quality.