Effects of phosphonate and salicylic acid treatments on anthracnose disease development and ripening of 'Kensington Pride' mango fruit.
Zainuri, Joyce D. C., Wearing A. H., Coates L., Terry L.
Author Affiliation: Agricultural Technology Programme, Department of Agronomy, Faculty of Agriculture, Mataram University, Mataram, 83125 Lombok, Indonesia.
Australian Journal of Experimental Agriculture 41 : 805-813
Abstract : This study conducted in Queensland, Australia, between 1996 and 1997 investigated the treatment of mango (Mangifera indica) fruit with 2 host defence-promoting compounds for the suppression of anthracnose disease (Colletotrichum gloeosporioides [Glomerella cingulata]). Fruits of the cultivar 'Kensington Pride' were treated at concentrations of up to 1000 mg/litre with either potassium phosphonate or salicylic acid. Applications consisted of various combinations of pre- and postharvest dips and vacuum infiltration. Postharvest treatments of up to 2000 mg salicylic acid/litre were evaluated in the second fruiting season. Fruits were either uninoculated or inoculated with the fungal pathogen. Colour, firmness and disease-severity were assessed during shelf life at 23°C. There were no significant (P>0.05) effects of potassium phosphonate or salicylic acid on anthracnose disease severity in the first season. Moreover, phosphonate or salicylic acid treatment did not significantly affect fruit colour or firmness changes. There were significant (P0.05) reductions in anthracnose severity in the second season, especially at the highest concentration of 2000 mg salicylic acid/litre. Mango fruit skin colour and firmness changes were also slowed down significantly (P0.05). These effects of salicylic acid were attributed to the inhibition of mango fruit skin ripening (senescence).