Impact of 1-MCP Spray During Flowering On Fruit Set and Yield of Cantaloupe

The purpose of this study was to determine the impact of field spray applications of 1-MCP (1-methylcyclopropane, AFXRD-038 powder, SmartFresh®) during flowering on fruit set and yield of cantaloupe cv. Mission. Experiments were conducted in a grower’s field in Batesville, Texas. Seeds were planted on 30 March (early planting) and 21 April 2010 (late planting). Standard planting configuration, fertilization, irrigation and pest control practices were followed. 1-MCP (10 g a.i. ha^-1) was applied at three timings (7, 14 and 7+14 days after appearance of the first female flower, DAF). Sequential female flowers and fruit counts (>1.3 cm diameter) were made in each planting and leaf chlorophyll index was measured during development. Harvests began 5 July and 12 July 2010, for the early and late planting, respectively. 1-MCP increased early fruit set as compared to control (0 g a.i. ha^-1) when measured 14 DAF in late planting. Leaf chlorophyll index was reduced by 1-MCP at 14 DAF in both plantings. Although senescence-related declines in leaf chlorophyll index were observed thereafter in both experiments, the extent was reduced by 1-MCP at 39 DAF in late planting. There were intense rain events from the end of June through the middle of July, causing high decay fruit production of up to 50% in early planting. However, this decay was significantly reduced by 1-MCP compared with control.  In late planting, 1-MCP significantly reduced the percentage of sunburn fruits. In both experiments, there was a trend for 1-MCP to increase marketable yield by increasing both fruit size and the percentage of marketable fruits. In order to demonstrate the feasibility of 1-MCP use in cantaloupes, more research is needed across a wider range of field conditions and environments.