Test of Concept: Gaseous 1-MCP Applied to Container-Grown Cotton Plants

Gaseous 1-MCP (1-methylcyclopropene) is used commercially in post-harvest handling of fresh fruits and vegetables, to control ethylene-mediated ripening processes.  The compound inhibits ethylene activity by occupying ethylene receptor sites.  It may also be beneficial to field-grown cotton by reducing ethylene-induced abscission of leaves and fruit.  Because of high vapor pressure of 1-MCP, however, response of field-grown cotton to this PGR has been inconsistent.  To test the 1-MCP concept, we tested the response of container-grown cotton plants to a commercial gaseous formulation of 1-MCP (SmartFresh).  Cotton was grown in 7-gal containers in the greenhouse, arranged in a replicated factorial design of SmartFresh treatment and water regime.  Designated plants were either fully irrigated or subject to progressive moisture deficit after first square.  Gaseous 1-MCP (SmartFresh) was applied to designated plants in fumigation tents after first square, while untreated plants were placed in separate tents at the same time.  Data were collected on water regime, abscission of leaves and fruit; leaf size and stomatal conductance, plant growth and dry matter partitioning.  Results will determine if 1-MCP modified cotton plant response to moisture deficit.