A severe fruit disorder of tomato (Lycopersicon esculentum Mill.) was induced with a tobacco form of tobacco mosaic virus isolated from blemished tomato fruit (cv. Ohio WR25) from a glasshouse crop in southwestern Ontario. Symptoms on green tomatoes consisted of slightly sunken, pale or yellowish-brown lesions with a thin, dark green margin. Lesions frequently expanded and coalesced along the flutes. The shoulders of the fruit were the most extensively affected areas. On mature fruit, the lesions appeared either silvery or silvery-brown and generally had a scabby appearance due to cracking and lifting of the surface tissues. Lesions were superficial and internal symptoms were not detected. First-truss inoculations prevented or delayed the fruit disorder. Inoculations at truss stages two, three, and four, however, resulted in development of affected fruit on inoculated as well as lower and subsequent trusses with the exception of the first truss. Similar susceptibilities to the fruit disorder occurred among the glasshouse cultivars Michigan Ohio (Burghart strain), Ohio WR25, Vantage, Veegan, and Vendor. No cross protection against the fruit disorder was provided by a mild tomato form of TMV introduced at the second-leaf stage.
Effect of silicon and potassium on tomato anthracnose and on the postharvest quality of tomato fruit (Lycopersicon esculentum Mill.)
