Ethephon concentrates and advances harvest for limited cluster greenhouse tomato crops

Ethephon (2-chloroethylphosphonic acid) was applied to single cluster greenhouse tomato crops (1000 ppm) at the green mature stage of fruit development or when 35% of the plants had fruits at the breaker stage. Fruits were harvested at the pink stage. Untreated fruit were harvested from 95 to 116 days after sowing whereas fruit from the green mature ethephon treatment were harvested from 92 to 102 days, three days earlier and with a reduction in the harvest window from 22 to 11 days. Fruit treated with ethephon at 35% breaker were harvested at the same time as untreated fruit, but harvest was completed after only 12 days. Fruit yield from the green mature ethephon treatment was reduced by about 30%, but there was no significant difference in fruit yield as a result of ethephon treatment at 35% breaker. Fruit color, firmness and soluble solids were evaluated one and six days after harvest. Fruit firmness and soluble solids were unaffected by treatment; however, fruit from the ethephon treatments were significantly redder in color. In a second experiment, ethephon was applied at 500 or 1000 ppm when 100% of the plants had fruit at the breaker stage. Fruit were harvested over a 7-day time interval compared to untreated fruit that were harvested over 14 days, and there was a small but significant increase in fruit yield for the 1000 ppm treatment. Both ethephon treatments also increased fruit soluble solids. For limited cluster tomato production systems, ethephon is effective in reducing the harvest window without loss in postharvest fruit quality.