Propagation from cuttings is the preferred method
for commercial plantations of dragon fruit and
ensures newly raised plants are genetically
identical to the parent so will have known fruiting
characteristics. If cutting material can be obtained
from a suitable cultivar, it’s a more rapid method
of establishing a crop. Dragon fruit plants produce
a large number of side shoots that can be removed
and used for propagation. Well-hardened cutting
material of at least eight inches or longer is sliced
from the parent plant and the cut surface allowed
to cure and callus for a week before planting out.
This process helps to prevent rotting during the
root formation stage. Cuttings are then placed
into a free-draining, sterile rooting medium and
left under warm, shaded conditions or on a heated
propagation bed until new roots have formed.
Seedling dragon fruit plant raised from seed collected from mature fruit.
Young dragon fruit plants grown in a free-draining
scoria-based hydroponic substrate.
Hydroponic Production
Dragon fruit plants can be grown in a containerized
system and respond well to the controlled irrigation
of hydroponic systems. Since at fruiting the long-lived
plants are large and require support, a suitable root
volume needs to be provided. Dutch bucket systems
or containers with at least 12 inches of depth are
suitable for young plants. At the time of planting out,
a stake or support needs to be installed for the young
plant to climb. The main stem should be pinched out
at the top once it reaches the height of the support
post. After this, three to four branches will grow and
extend outwards. These will bear the first fruit of the
plant. Branches need to be guided to grow downwards
and have the tips pruned out when they reach around
three feet in length. This helps restrict the height of
the plants by preventing unpruned stems growing
upwards indefinitely and maintains a more productive
and compact plant shape.
Drainage is essential with dragon fruit plants, with
substrates such as expanded clay, gravel, and coarse
perlite being mediums that help prevent over-saturation
of the root zone. Drip irrigation of nutrient solution in
either an open or closed system is suitable and helps to
maintain aeration around the roots. While dragon fruit
require a similar amount of water under warm growing
conditions as mature tomato or cucumber plants, this
needs to be applied in small but frequent amounts as
the root system is quite shallow and fibrous.
Water and Nutrient Requirements
Like most fruiting crops, dragon fruit requires higher
ratios of nitrogen in the vegetative stages of growth
and increased potassium when in fruit. Since a
number of relatively large fruit are produced in a
short time frame on each plant under optimal growing
conditions, sufficient potassium needs to be supplied
to maintain fruit yields and quality. Pitaya do not
require the same high EC that may be applied to crops
such as tomatoes to maintain fruit quality. EC levels
in the range of 1.0 for young plants up to 1.4 (with a pH
of 5.8–6.0) are suitable for long-term production. EC
levels should be measured in the drainage or leachate
solution draining from each growing container to
ensure EC is not climbing during warm growing
condition as plants are sensitive to salinity damage.
Under optimal temperatures, mature plants can use as
much as one to 1.3 gallons of water per day or as little
as 0.6 gallons under cool growing conditions.
38
Maximum Yield