Table of Contents
Raveh, E., J. Weiss, A. Nerd, and Y. Mizrahi. 1993. Pitayas (Genus
Hylocereus): A new fruit crop for the Negev desert of Israel. p.
491-495. In: J. Janick and J.E. Simon (eds.), New crops. Wiley, New York.
Pitayas (Genus Hylocereus): A New Fruit Crop for the Negev Desert of Israel*
Eran Raveh, Julia Weiss, Avinoam Nerd, and Yosef Mizrahi
- RESULTS AND DISCUSSION
- Table 1
- Table 2
- Table 3
- Fig. 1
- Fig. 2
- Fig. 3
- Fig. 4
- Fig. 5
- Fig. 6
- Fig. 7
Members of the genus Hylocereus (Pitaya) (Fig. 1), Cactaceae are
epiphytes which produce high-quality fruits that resemble those of the prickly
pear (Opuntia ficus-indica Mill.) in appearance but differ from the
prickly pear in that they contain very small seeds. Unlike the prickly pear,
the peel of pitaya fruits is thornless or becomes thornless during ripening.
Attempts are currently being made to domesticate species of the shrub in
Central America and in Israel (Barbeau 1990; Nerd et al. 1990). Some
agrotechniques methods have been developed (Barbeau 1990; Arcadio 1986), but
there remains a lack of detailed information about conditions required for
growth and fruit production.
Twenty three genotypes of various Hylocereus species were first
introduced and propagated in our institutes nursery in 1986. The plants
characteristics were studied in our greenhouse, and some genotypes were planted
in four experimental orchards at various sites in the Negev Desert (Nerd et al.
1990). When the shrubs were planted in the open sun, they developed bleaching
symptoms and growth was inhibited. Plants recovered only after they were
In this paper, we describe fruiting in several selected clones and the effect
of shading on photosynthesis and growth in two of these clones.
Seeds and cuttings of various Hylocereus species obtained from
individuals, and botanical gardens in California, Columbia, Equador, and Israel
were propagated in our nursery. In greenhouse studies, three plants of each
clone were planted, and plant development, flowering and fruit set, and quality
were evaluated. A shading experiment was carried out with cuttings of H.
polyrhizus and Hylocereus sp. type Equador (species not yet defined)
planted in 15-liter buckets filled with a nursery mixture were placed in a
nethouse. Three levels of shading, 30, 60, and 90%, were provided by means of
nets of different densities. Each treatment contained 16 plants of each
species. Growth parameters (length and weight) were measured during the
winter-spring (November-April) of 1990-1991.
The species can be divided into two groups according to fruit characteristics
and fruit development: those having large red fruits and short fruit
development time (group Alon), and those having smaller yellow fruits and
longer time of fruit development (group Katom) (Table 1, Fig. 2). Katom fruits
were judged to be superior (by our team of tasters), probably because they had
the highest total soluble solids content (Table 2). In general, fruits of all
the species were very juicy, with a pleasant sweet-sour taste.
Hylocereus species are described as being self-compatible, but
cross-pollination by insect occurs frequently (Cacioppo 1990). We found that
some species set fruit after hand-self pollination, whereas others did not
(Table 3). Thus, within the genus Hylocereus, there are both
self-compatible and self-incompatible species. In one species, H. sp.
type Katom, we found that self-pollination occurred without a pollen vector.
Hand-cross pollination between the various species led to 100% fruit set
indicating no incompatibilities among these species. The flowering period of
Hylocereus genus starts in mid-May and the last flowers appear in
November. Flowering occurs in two or three waves. For the cultivation of
self-sterile plants, we recommend that several species be planted together to
guarantee the availability of cross-pollination partners. Flowers of all
species were opened for only one night between two hours before dusk and three
hours after dawn. Other reports claim that Hylocereus flowers are open
during several nights (Cacioppo 1990; Barbeau 1990).
Maximum and minimum air temperatures fluctuated around 30° and 8°C,
respectively, during the 150 days of the experiment (mid-October to mid-March),
and the three parts of the nethouse exhibited similar maximum and minimum
temperatures (Fig. 3). Maximum levels of photosynthetic active radiation (PAR)
increased with decreasing shading (Fig. 4), i.e., the main difference among the
three sections of the nethouse lay in the radiation intensity.
Growth was expressed as the relative growth rate (RGR) which is defined as:
(Lt2-Lt1)/Lt1 &0198; day, where Lt1 is total stem length at time t1 and Lt2 is total
stem length at time t2.
Growth of H. polyrhizus increased significantly in the winter time
(November-February.) with decreasing shading. This tendency was also found
less significantly for Hylocereus sp. type Equador (Fig. 5).
The fresh weight of the plants on the 150th day is shown in Fig. 6. The weight
increase in H. polyrhizus was greater than that in Hylocereus sp.
type Equador (fresh weight at zero time was 148±13 g SE and 60±4 g,
respectively), particularly at the lowest and medium levels of shading. These
findings are compatible with those for the RGR measurements, indicating that
H. polyrhizus exhibits a higher tolerance to high radiation than the
Equador type. The two species differed in CO2 uptake rate (Fig. 7), the rate
being correlated to growth. Values of CO2 uptake at the lowest shading level
were in the range found by Nobel and Hartsock (1990) for other epiphytic cacti.
Cultivation of Hylocereus plants in the Negev will have to be restricted
to shadehouses, with the shading level being adapted to the specific species.
To ensure maximum pollination, compatible clones or species will have to be
planted in close proximity and pollinating insects will need to be made
available in the shadehouse, perhaps by placing beehives in the shadehouse.
Crossing between various species of the genus Hylocereus is feasible and
could lead to improved types.
- Arcadio Luis, B. 1986. Cultivo de la Pitaya. Federacion Nacional de
Cafeteros. Bogota, D.E. p. 1-18.
- Barbeau, G. 1990. La pitahaya rouge, an nouveau fruit exotique. Fruits
- Cacioppo, O.G. 1990. Pitaya: una de las mejores frutus producida por
Colombia. Inforamtive Agro Economico. Feb. p. 15-19.
- Nerd, A., J.A. Aronson, and Y. Mizrahi. 1990. Introduction and domestication
of rare and wild fruit and nut trees for desert areas, p. 353-363. In: J.
Janick and J.E. Simon (eds.). Advances in new crops. Timber Press, Portland,
- Nobel, P.S. and L. Hartsock. 1990. Diel patterns of CO2 exchange for
epiphytic cacti differing in succulence. Physiologia Plant. 78:628-634.
*The authors would like to thank the following agencies: US-AID-CDR and the
Rich Foundation for partial support of this research.
Table 1. Fruit appearance of pitayas under shade in the greenhouse in the third year.
|Hylocereus species ||Peel color ||Pulp color ||Peel morphology|
|H. sp. type Alon ||Light red ||White ||Large scales with light green tips,
|H. costaricensis ||Dark red ||Violet ||Small scales, fruit round |
|H. sp. type Katom ||Yellow ||White ||Spines, easy to remove, peel bearing
warts, fruit oblong|
|H. paolyrhi ||Dark red ||Violet red ||Large scales with dark green tips, fruit
|H. sp. type Equador ||Yellow ||White ||Spines, easy to remove, peel bearing
warts, fruit oblong|
Table 2. Fruit quality if pitayas under shade in the greenhouse in the
|Hylocereus species ||Fruit weight (g) ||Pulp/peel fresh weight basis ||DW (%) ||TSS (%) ||Reducing sugars (mg/g fw) ||Titratable acidity (meq/g fw) ||pH|
|H. sp. type Alon ||595±32 ||3.7±0.4 ||16.4±0.8 ||10.9±0.5 ||107.2±7.8 ||32.3±6.9 ||4.9±0.02|
|H. costaricensis ||308±15 ||3.1±0.4 ||16.2±0.8 ||12.2±0.8 ||84.6±7.3 ||50.6±8.9 ||4.7±0.02|
|H. sp. type Katom ||96±8 ||1.1±0.1 ||20.9±0.3 ||16.6±2.5 ||93.7±13.3 ||23.1±3.5 ||4.6±0.00|
|H. paolyrhi ||327±24 ||2.0±0.1 ||17.2±1.2 ||10.5±0.5 ||68.8±6.4 ||63.8±2.0 ||5.2±0.50|
|H. sp. type Equador ||115±8 ||--- ||--- ||--- ||--- ||--- ||---|
Table 3. Compatibility systems of various Hylocereus
zSix to ten flowers were used for each treatment.
|Plant species ||Hand-cross pollination (% fruit set) ||Hand-self pollination (% fruit set) ||Covered, no hand pollination (% fruit set)|
|H. sp. type Alon||100||47||0|
|H. sp. type Katom||100||100||100|
|H. sp. type 10487||100||67||0|
||Fig. 1. Hylocereus paolyrhi, 3-years-old, growing on trellis system under netting, at Beer-Sheva (October 1991).
Fig. 2. Length of fruit development stage in fruits of var-ious species
of the genus Hylocereus. Bars represent ±SE.
Fig. 3. Maximum and minimum air temperatures at three levels of
Fig. 4. Noon PAR at three levels of shading.
||Fig. 5. Relative growth rate (RGR) of H. polyrhizus (A) and
Hylocereus sp. type Equador (B).
Fig. 6. Fresh weight of H. polyrhizus and Hylocereus sp.
type Equador after five months in the shadehouse. Mean fresh weight of plant
at planting was 148±13 g for H. polyrhizus and 60±4 g for
Hylocereus sp. type Equador. Bars represent ±SE.
Fig. 7. Daily CO2 uptake of H. polyrhizus and Hylocereus
sp. type Equador. Measured mid March 1991. Values are means for five plants.
Bars represent ±SE.
Last update September 15, 1997