The Use of Fungicide Alternatives for Controlling Postharvest Decay of Strawberry and Orange Fruits

Abstract

Control measures of postharvest diseases of strawberry and navel orange fruits using hy- drogen peroxide, calcium chloride and chitosan were evaluated under in vitro and in vivo conditions. All tested concentrations of chemicals used were able to reduce the linear growth and spore germina- tion of B. cinerea; R. stolonifer; P. digitatum and P. italicum. Complete inhibition of linear growth and spore germination was obtained with concentrations of 1.5 and 2.0% of all treatments. Under storage conditions, significant reduction in descending order of mould incidence was observed in strawberry and orange fruits treated with ascending concentrations of calcium chloride, hydrogen peroxide and chitosan. Obtained data revealed significant reduction in mould incidence in fruits when treated by calcium chloride and chitosan 12h before artificial inoculation with the mould pathogens, while hy- drogen peroxide showed the opposite result. The present study demonstrated that the application of hydrogen peroxide is superior to treatment with calcium chloride or chitosan enhanced the control activity against mould pathogens which as it expressed was as either percentage of diseased fruits or decay development as rotted tissue weight of strawberry and navel orange. The applied tested chemi- cal might act as contact and systemic fungicides which have a protective or therapeutic effect.