FACTORS REDUCING FRESH GRAPEFRUIT PACKOUTS IN FLORIDA: CAN PACKOUTS BE IMPROVED?

摘要

The greatest financial returns for grapefruit are achieved by selling fruit for the fresh market. While Florida growing conditions yield fruit of exceptional internal quality, they also favor the development of cosmetic defects that often render the fruit marketable only for juice. Such defects include under/over-sized fruit, windscar (and other mechanical peel injuries), poor fruit color, misshapen fruit, fungal blemishes (e.g., melanose), arthropod damage (e.g., rust mite), sunburn, and freezing injury. Some of these defects are major elimination factors each year, but the incidence and relative importance of most varies from year to year. Average grapefruit packouts have declined by almost 1/3 for both white and colored varieties over the past two decades, suggesting that market demands and/or cultural practices may have shifted. Defects due to windscar, melanose, poor shape, and off-size were identified as top causes of fruit elimination, indicating that practices to reduce these fruit blemishes might have a substantial impact on improving packouts and returns to Florida growers and packers. Packouts of red varieties continue to be significantly higher than those for white grapefruit, but our limited data do not support the idea that tree age(white grapefruit trees in Florida tend to be older) is the primary reason. Packouts tend to decrease as the season progresses. Therefore, lower packouts can be expected when packing for markets that order grapefruit later in season. Awareness of this trend might enable some growers to target earlier sales for better returns, but it is unlikely to affect packouts across the entire industry. When surveyed, packinghouse managers cited market demands for more perfect fruit and shifts in sales to more demanding markets (such as Japan) as the most likely causes of declining packouts.