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3 different genetic types (not the same clone or variety). Cross pollination between the different types in the planting will assure a better fruit set and size. Moths and bats are good pollinators, since flowers open at night when there is no bee activity. However, moth and bat pollination has not been commonly observed. Flowers of some cultivars remain open during the early to mid-morning hours and may be visited by bees. Alternately, hand pollination may be done during the night and early morning hours by collecting pollen (or whole stamens) from one flower and applying it to the stigma of other flowers. Varieties At the present time, there are are large number of named cultivars and unnamed selections. Many selections have been made and are available in the US. There are breeding programs in Taiwan, Vietnam, and Israel. In countries where pitaya are native, selections from the wild are being used. Many of these have been introduced into countries that are interested in growing them. Unfortunately, information on the self-incompatibility of these cultivars and selections is not well documented. This makes cultivar (variety) recommendations difficult at best and potentially unreliable. Climate Pitayas grow well in tropical and subtropical climates, mostly free of frosts and freezes. They tolerate cool or warm climates, provided temperatures do not exceed 100°F (38°C). They tolerate some shade and may be injured by extreme sunlight. They are considered a full sunlight crop in their native countries. Initial estimates from native areas suggest that optimum temperatures for growth are 65C77°F (18C25°C). Insolation (Sunburning) Severe stem damage has been reported from sunburn in some growing regions with low humidity or high altitude. About 30% shading is recommended during the first

3 to

4 months after planting and where insolation is at damaging levels. However, too much shade results in low production and poor quality fruit. Cold Pitayas may be damaged by exposure to below freezing temperatures (31°F;

-2°C) of long duration. However, they recover rapidly from light freezing injury. Wind Pitayas appear to tolerate windy conditions, however, very strong winds or hurricanes may cause considerable damage to trellises or supports and consequently to the plants. Salt Pitayas may tolerate saline soil conditions. Some references classify them from moderate to highly tolerant to salts. Propagation Pitaya may be propagated from seed, however fruit and stem characteristics are variable, and the time from planting to fruit production may be up to

7 years. Asexual propaga- tion is preferred, and the use of stem cuttings is widespread. Usually entire stem segments of 6C15 inches (12C38 cm) are used. A slanted cut is made at the stem base, then the cuttings are treated with a fungicide and then left to cure (dry and heal) for 7C8 days in a dry, shady location before they are planted directly in the field or in well drained media in pots. Some propagators apply a root hormone to the cuttings after curing but before planting them. Cuttings grow very fast (1.2 inches [3 cm] per day) and many produce fruit in 6C9 months after planting. Longer cuttings usually reach the trellis supports faster than shorter ones. Pitayas may also be grafted, but this practice is not common. Grafting has potential for selection of rootstocks adaptable to various soil types and problems. Cuttings take about 4C6 months to develop a good root system in pots and be ready for planting. Production (Crop Yields) Three- to 4-year-old plants may produce about