Cane-type Dendrobiums

(First of a series)

MANILA, Philippines - Dendrobiums are some of the more popular orchids for the tropics. It is one of the bigger genera of orchids in the world, having more than 1,000 representative species in different ecological situations. They may be found in tropical, temperate, deciduous or arid areas. The bigger bulk of Dendrobium types in the world market are descendants from the section Phalaenanthe or the Dendrobium phalaenopsis group. The big showy floral segments are responsible for its popularity among orchid breeders.

The phalaenanthe section of Dendrobiums comprises only of few species. One species which has played a prominent role in development of the popular cutflower and potplant types is the Dendrobium phalaenopsis. Dendrobium phalaenopsis is native to Queensland, Australia. 

The species was introduced into Cebu Island and it became feral (escaped cultivation) and localized for sometime in Carcar, Cebu. Because of its attractive flowers, they were overcollected during the 80’s and are now extinct in its feral range. Because of it commercial importance, conservation efforts are being done to resurrect this strong-growing type. 

Dendrobium Cultivation

The biggest volume of Dendrobium cutflowers grown and traded in the world are the cane type hybrids, generally derived from the phalaenanthe and the spatulata section. The phalaenanthe gives the size of the flower segments while the spatulata improves the number of blooms per spike and the number of spikes per stem (pseudobulb). 

Cane-type Dendrobiums are the easiest plants to grow in dry areas of the world. The plants are generally trouble-free, grow fast and produce big volumes of flower spikes. This is the main reason why most of the cane-type Dendrobium growers of Hawaii are located in the Waianae, the driest part of Oahu Island.

Growing the cane-type Dendrobiums in the tropical countries like the Philippines poses a big challenge. Continuous rains during the rainy season damages the leaves leaving the plants with leafless canes. With less photosynthesizing leaves, the floral output will also suffer.

Cane-type Dendrobiums are better grown protected by the eaves of houses or under plastic canopies. 

Some people “Orchid Experts” argue that Thailand, the biggest producer of Dendrobium cutflower is also tropical and Philippines will likewise succeed in cultivation for export. This argument is valid but rains during the worst rainy season in Thailand last only an average of 30 minutes to one hour daily. It is tantamount to watering the plants daily in contrast to the siyam-siyam (continuous downpour for 9 days) in the Philippines.

The cane-type Dendrobiums are better grown in the drier west side of the country provided there is good irrigation system.

Cutflower Varieties

The University of Hawaii team (Dr. Haruyuki Kamemoto, Dr. Tessie Davide Amore, & Dr. Nellie Sugii) through the help of the Dendrobium Orchid Growers Association (DOGA) has developed some of the strongest growing and most productive lines of seed-grown amphidiploid Dendrobiums for the cutflower and potplant industry. All the lines are given a UH number and UH names (e.g. UH800 = Uniwai Mist, UH44 = Uniwai Blush, UH306 = Uniwai Pearl). 

All the breeding stocks of UH lines are with the University of Hawaii and the hybrids may only be obtained from 8 accredited DOGA propagators, based in Hawaii. The propagators give back a portion of the revenue from the sale of the UH lines to support horticultural research in University of Hawaii at Manoa.

It is safe to assume that UH lines may not be produced outside of Hawaii. All crosses derived from the UH materials may not be called UH lines. For the past 2 decades, some unscrupulous orchid propagators are passing off locally bred materials as UH lines. The locally produced materials are of course inferior and may be genetically defective. Growers who were made to believe that they purchased UH materials complain of high bud drop incidences, peloria with shrunken petals and low floral spike count. The most devastating defect in production point of view is the buddrop. Some areas have more than 25% buddrops not fit for commercial purposes. That translate to a minimum 25% loss in revenue at the same time increases cost of production.

Thai-bred materials has more phalaenanthe bred into the genepool to increase the size of flower segments. Most Thai materials in the market are cloned materials and thus more genetically uniform.

Dendrobium Propagation and Pest Management in next installment.