Watermelons should be harvested at full maturity to ensure that good quality fruit are delivered to the market. The fruit do not develop internal color or increase in sugar content after being removed from the vine. Harvesting usually begins 3-4 months after planting.
The ground spot (the portion of the melon resting on the soil) changes from pale white to a creamy yellow at the proper harvest maturity. The ground spot color is easily revealed by gently rolling the fruit over to one side while still attached to the vine. Also, tendrils near fruit stem have changed color from green to brown.
Very experienced workers can determine ripeness stage based on the sound produced when the fruit is thumped or rapped with the knuckles. Immature fruit will give off a metallic ringing sound whereas mature fruit will sound dull or hollow.
Sugar content (measured as soluble solids by use of hand held refractometer) of 10 % or more in the flesh near the center of the melon.
Lycopene content peaked 7 days postharvest and intensity of flesh color increased concomitantly; yellowing of flesh was detected at 14 days.
Rootstocks improved postharvest flesh firmness and lycopene content and enhanced flesh color. Rind was minimally thickened by rootstocks and declined with storage.
The harvest operation is a manual process which is the most labor-intensive part of producing watermelons. Due to their large size and susceptibility to splitting or cracking under mechanical stress, watermelons should not be harvested in the early morning when they are most turgid.
Handling should minimize fruit injury which may be caused by impact or abrasion. Shading is necessary in order to protect watermelon from direct sunlight which causes sunburn.
Watermelon post-harvest
