The flesh of the apricot becomes brown at the point where growth has manifested in the fruit tissue, expressed as a small lesion at first, expanding under favourable conditions. The lesion is firm. Spore masses of a tan / light-brown colour, often in the form of tufts / clusters, appear in concentric rings, as the fungus progresses in the host tissue. The skin of the infected fruit does not readily slip away when one’s finger is slid across the lesion. The skin of infected apricots may darken during storage, hence the reference to ‘brown rot’.
Brown Rot. Darkening of the skin, peach example.