Effect of skin coatings on the development of black spot in stored Valencia oranges

Abstract

The development of black spot (Guignardia citricarpa Kiely) lesions on Valencia oranges stored at 80°F was reduced by various post-harvest skin coatings. Effective treatments included waxing, which is already in commercial use. The effects of the skin coatings on weight loss and fruit respiration were also studied. The results suggest that the effectiveness of the treatments in inhibiting black spot may have been due to their reducing the rate of respiration of the fruit. It is suggested that post-harvest treatments are complementary to orchard control methods, and that both are necessary for best control of black spot.