Flowering, Pollination, and Fruit Set
Under indoor or greenhouse cultivation, dragon fruit
can be manipulated to increase the length of the
flowering and fruiting period. Being a long-day plant,
control over flowering with use of artificial lighting
is possible and can increase yields and productivity
significantly. While day length can be extended
with the use of lighting, it is also possible to induce
flowering by using a night break by providing a low
level of light between 11 p.m. and 2 a.m., similar to
commercial cultivation in Taiwan.
Pitaya are night bloomers and fragrant flowers
are only viable for one to two nights with petals
opening in the evening and wilting by daybreak. In
their native environment, moths and bats pollinate
the flowers, however, many commercially available
cultivars are now self compatible and do not require
cross pollination. Hand pollination, however, can
help give higher levels of fruit set and greater fruit
weight. This process involves physically removing
the anthers from one flower and touching them to
the stigma of another flower at the time of opening.
Alternatively, the pollen can be collected using a
small brush and used to pollinate several different
flowers. Once pollination has been successfully
completed, fruit development is rapid and harvest
typically occurs 28 to 30 days after the flower closes.
Once fruit have fully expanded and have a good
level of skin coloration, harvesting can occur.
“
Like most fruiting crops,
dragon fruit requires higher ratios of
nitrogen in the vegetative stages of growth
and increased potassium when in fruit.”
However, leaving the fruit on the plant for an
additional 10 to 15 days has been shown to
improve brix (sugar levels) in many cultivars.
Brix levels for dragon fruit are usually
between 12 to 13 percent but can be as high
as 20 percent in the red-fleshed varieties. Once
harvested, fruit can be stored for up four weeks at
temperatures of 43-50°F with a relative humidity of
90 to 95 percent to prevent desiccation.
Dragon fruit are a fascinating
and attractive plant with
fragrant night blooming flowers
and exotic fruit. They are also a crop
with good potential for the well-controlled
irrigation and nutrition that hydroponic methods
can provide. Through use of artificial lighting,
day-length extension, and careful selection of
growing substrates, pitaya are likely to become a
popular greenhouse and indoor garden specimen.
Maximum Yield 39