PESTS & DISEASE

Common diseases that affect limes are algal disease, citrus canker, citrus greening, scab, foot rot, greasy spot, postbloom fruit drop, blotch disease, green and blue mold, stem-end rot, and end breakdown or rot. Pests of concern include the Asian citrus psyllid, brown citrus aphid, leafminers, red and snow scale, and red, rust or broad mites.

References: Agricultural Marketing Resource Center, UC Davis Postharvest Technology Center.

CULTIVATION, STORAGE & PACKAGING

Preharvest:
Limes require a tropical to subtropical environment with rainfall of between 80 and 150 inches per year to thrive. They are very susceptible to freezing and need long periods of hot ambient temperatures to reach maturity. Limes are harvested throughout the year as trees bear fruit all year long. Commercial groves usually utilize overhead sprinkler irrigation for watering. Both types of lime tree can be grown in a variety of soils, even sandy or rocky soil. Tahiti lime trees grow to approximately 15 to 20 feet tall with widely-spread thornless branches, many of which will droop to the ground. Fruit may produce a few seeds if trees are planted among other citrus trees and flowers have no usable pollen. Bloom to maturity is between 90 and 120 days; trees reach full production after about eight to ten years.

Key lime trees seldom grow more than 12 feet tall. Branches are slender and thorned. Tree varieties without thorns tend to be smaller with darker leaves and lower production. Trees are very sensitive to cold; foliage is damaged at 30 to 32°F and trees may die from exposure at 29°F or below.

Postharvest:
Limes are packed into bins in the field and transported to packinghouses for cleaning, grading, sizing, washing, waxing, and final packing in corrugated cartons for shipment. Cartons can be 10, 20, 40, or 55 pounds each. Limes can generally be kept for up to eight weeks between 50 and 55°F with 90 to 95% relative humidity. Rates of respiration increase with higher temperatures.

Key limes are best picked when their surface is smooth, color is light green and fruit feels slightly soft. Picked limes ripen quickly in warm climates but are also prone to chilling injury under about 45°F. Storage at 48°F with 85 to 90% humidity is recommended. Packing limes in polyethylene bags with ethylene absorbent delays ripening and moisture loss during shipping.

About 40% of Tahiti limes are processed for lime juice concentrate. Unusable limes are used for juice and peel oil extract. Tahiti limes do not require curing as they stay in marketable condition for as many as 6 to 8 weeks when refrigerated. Rough handling or handling of overripe limes is discouraged as they are susceptible to oil spotting (oleocellosis) and stylar-end breakdown.

References: Agricultural Marketing Resource Center, Purdue University Center for New Crops & Plants Products, UC Davis Postharvest Technology Center, University of Florida/IFAS Extension.

Page 2 of 3123