Post Harvest
The longevity and quality of pot mums can be increased by properly managing production and handling practices. The following information is based on work done by Dr. Terril Nell and Dr. James Barrett at the University of Florida.
Maintain high light levels: Light levels of approximately 6,000 footcandles maximize longevity. Light levels below 1,000 footcandles for the final 3 to 4 weeks of production can decrease longevity by 8 days. Flower diameter was less and flowering was delayed under low-light conditions.
Use correct nitrogen fertilizers: A nitrate-ammonia ratio of at least 60:40 should be maintained until bud removal. Higher ammonia (including urea) will lead to increased leaf yellowing and reduced longevity.
Stop fertilizer: Termination of fertilizer at bud removal (3 to 4 weeks prior to sales) extends longevity 11 to 14 days and makes pots better acclimated for shipping.
Ship cool: Flowering chrysanthemums shipped for 7 days at 40°F lasted 23 days under interior conditions, while plants shipped at 75°F lasted only 10 days. Plants shipped at 75°F were of poor quality after shipping.
Hold cool: Maintaining pot mums under interior conditions at 65°F increased longevity by 13 days compared to interior temperatures of 80°F.
Stage of development: Pot mums should be shipped at the 1/4 (Stage 2)- to 1/2 (Stage 3)-open stage of development for best consumer keeping quality.