Pre-harvest bagging and coating treatment effects on lenticel discolouration in 'B74' mango fruit

T.M. Nguyen, D.C. Joyce, M. Gupta, P.J. Hofman, A.J. Macnish, J.R. Marques
'B74' mango fruit are sensitive to lenticel discolouration (LD). Exposure of the fruit to water during production and postharvest handling can increase LD. We propose that water infiltration into the lenticel cavity increases turgor in adjacent cells that leads to tissue strain, cellular stress and defence, and enzymatic browning. In the current study, we tested the efficacy of pre-harvest fruit bagging and coating treatments to reduce water infiltration and LD. Individual fruit on 'B74' trees at a commercial orchard were covered with a white paper bag, or coated with either 5% RainGard™ (a cracking suppressant), or 5% Raynox® (a carnauba wax-based coating) at two months before harvest. RainGard™ and Raynox® were re-applied to fruit at one month and one day before harvest. Additional fruit were coated with 2.5% Natural Shine™ TFC210 (a carnauba wax-based coating) at one day before harvest. The fruit were harvested, dipped in a detergent and a fungicide, and brushed. They were exposed to 10 µL L-1 ethylene at 20°C and allowed to ripen. The result showed that bagging and coating with Natural Shine™ TFC210 were the most effective treatments. They reduced LD on 'B74' fruit by 30-55% and 39-43% at the green mature and full ripe colour stages, respectively, as compared to the non-bagged and non-coated control. Pre-harvest bagging and coating treatments did not affect fruit firmness and lenticel morphology.
Nguyen, T.M., Joyce, D.C., Gupta, M., Hofman, P.J., Macnish, A.J. and Marques, J.R. (2016). Pre-harvest bagging and coating treatment effects on lenticel discolouration in 'B74' mango fruit. Acta Hortic. 1111, 377-384
DOI: 10.17660/ActaHortic.2016.1111.54
'B74' mango, bagging, coatings, lenticel, dye uptake

Acta Horticulturae