Effect of pre-harvest polymer coating of Tommy Atkins, Kent or Keitt mangoes on disease incidence and fruit physico-chemical characteristics after extended cold-storage.
Oosthuyse S. A.
Author Affiliation: HortResearch SA, PO Box 3849, Tzaneen 0850, South Africa.
27 : 80-83
Abstract : In an experiment conducted in South Africa, fruits of mango cultivars Tommy Atkins, Kent or Keitt were manually immersed in 100% PolymerCoat early in the season. Fruit coating with PolymerCoat was evaluated as a non-chemical means of controlling anthracnose (Colletotrichum gloeosporioides [Glomerella cingulata]) and soft brown rot (Botryodiplodia theobromae), both diseases resulting from pre-harvesting infections that become apparent after harvesting, when ripening commences. Comparison was made with monthly copper oxychloride spraying. Coating was carried out in late October and during November 2006 prior to and after the occurrence of rain. After harvesting, fruits were stored for 28 days at 11°C, and then allowed to ripen further at 20°C. Coating in late October or early November prior to the commencement of rain was the most effective in reducing the incidence of anthracnose compared to later coating, and better or equal to monthly copper oxychloride spraying commencing in late October. In Keitt, coating was superior to copper spraying in reducing the incidence of anthracnose; in Kent and Tommy Atkins, early coating was as effective as copper spraying. Generally, coating after the onset of rain was less effective against anthracnose. The incidence of soft brown rot was low in Tommy Atkins, and high in Kent and Keitt. Differences among the treatments were not significant. Coating did not affect blush skin colouration, but generally reduced ground skin colouration, taste appeal, juice total soluble solids content, and pulp colouration. Coating was not effective in preventing solar injury. Fruit attractiveness to fruit fly was increased by PolymerCoat.