Pre-harvest chemical elicitor treatment enhances induced resistance in harvested banana fruit cv. ‘Embul’ and reduces anthracnose caused by Colletotrichum musae

Developing banana fruits cv. ‘Embul’ were treated in the field with chemical elicitors, Bion®, salicylic acid (SA) or K₂HPO₄ at two stages, 2 and 4 or 9 and 11 weeks after bunch emergence. Fruits harvested 14 – 15 weeks after bunch emergence were inoculated with Colletotrichum musae, and the development of anthracnose was assessed during ripening. Treatment with Bion® or SA at 9 and 11 weeks after bunch emergence while delaying the disease incidence significantly reduced (p < 0.05) the severity of the disease by 43 % and 65 %, respectively compared to the control. SA (500 mg/L) treatment was 22 % more effective than Bion® (200 mg/L) while the treatment with K₂HPO₄ (20 mg/L) increased the disease severity by 5 %. Bion® or SA-treated fruits when challenge inoculated with C. musae after harvest showed a significantly enhanced chitinase activity (p < 0.05). There was also an increased β–1,3–glucanase activity and antifungal activity of the fruit peel compared to the controls. The elicitor treatment did not affect the fruit weight or postharvest quality.

DOI: http://dx.doi.org/10.4038/jnsfsr.v42i2.6994

J.Natn.Sci.Foundation Sri Lanka 2014 42 (2): 101-110