EFFECTS OF 1-METHYLCYCLOPROPENE ON FLUE-CURED TOBACCO (NICOTIANA TABACUM L.) WITH THE INITIATION OF CHEMICAL SENESCENCE FROM APPLICATIONS OF 2-CHLOROETHYLPHOSPHONIC ACID

Abstract Ripening and holding ability of flue-cured tobacco (Nicotiana tabacum L.) are critical components of producing high-quality leaf desired by the tobacco leaf buyers. Research was conducted in North Carolina during 2006 to 2008 at 2 locations to determine if applications of 1-methylcyclopropene (1-MCP) could inhibit chemically enhanced senescence from applications of 2-chloroethylphosphonic acid in flue-cured tobacco. Treatments consisted of 1-MCP at 26 g ai ha−1 and at 13 g ai ha−1. Applications of 1-MCP were initiated before optimal ripeness on the basis of traditional judgment of harvest timing and included applications at: 14 days before normal final harvest, 14 and 7 days before normal final harvest, 7 days before normal final harvest, and 7 and 1 days before normal final harvest. Treatments also included applications of 2-chloroethylphosphonic acid at 1,680 g ai ha−1 to enhance chemical senescence at the normal harvest timing. Soil plant analysis development (SPAD) values were taken before (b...