In this article we will discuss about:- 1. Introduction to Bamboo Research in Philippines 2. Bamboo Propagation 3. Harvesting Methods/Techniques.
Introduction to Bamboo Research in the Philippines:
The taxonomy and classification of bamboos are far from satisfactory. The herbarium specimens available do not represent the bamboos of the world. Moreover, they are often inadequate to represent the species. Most specimens are leafy or flowering branches. Moreover, because many bamboos flower infrequently, they are often ignored completely by plant collectors.
In the Philippines, there are a number of taxonomic problems which can be solved only by prolonged and extensive observation of field characters.
In 1998, Pancho and Obien, published “New Records of Bamboos of the Philippines”. New records of 17 species and one cultivar of bamboos for the Philippines, distributed in five genera, including their synonyms, key, description, illustrations, common name(s), economic importance, and existence are presented.
In 1989, Widjaja conducted training on bamboo taxonomy in ERDB, College, Laguna. After the training, she visited some places in the Philippines (Cagayan province, Baguio and Davao) and collected bamboo specimens.
In 1990, Widjaja published an article entitled “Progress in the study of Malesian Bambusoideae” wherein she discussed some specific problems related to taxonomic delimitation of “Malesian Bambusoideae”, including those of Philippine bamboos.
First, she discussed the uncertain identify of “bayog” which was previously included in Dendrocalamus merrilianus. It needs to be studied further by comparing it with Bambusa blumeana and its varieties as well as with the Chinese spiny bamboos. Due to its spiny character and long rachilla on its spikelets, “bayog” certainly cannot be included in Dendrocalamus.
The identity of “laak”, the most useful bamboo in Mindanao for banana props, needs to be clarified further, because it has been generally referred to as Guadua philippinensis which has recently been transferred to Sphaerobarnbos by Dransfield (1989). Since Sphaero bambos is a scrambling genus, it seems that, the stout and erect-culmed “laak” has been wrongly identified. The records of Arundinaria niitakayamensis and Pseudostachyum polymophum from the Philippines require confirmation because the two genera are not yet known to occur in Malesia. The taxonomic status of Schizostachum palawanense, S.’textorium, S. toppingil, S. curranii, S. diffusum, S. dielsianum, and S. fenixii which have climbing habits need reinvestigation because, in many respects the morphological characters (climbing or zigzag habit of the culms, presence of a girdle which can be seen clearly when young, and the peculiar fruit structure) suggest affinity with other genera than Schizostachyum.
Some of the Philippine bamboos included in Dinochloa have two florets, whereas the current generic concept of Dinochloa only allows the presence of one floret. Since the fruit structure of some of the Philippine Dinochloa species is also distinctive, a complete morphological and anatomical comparative study involving many species of other closely related genera is necessary. Other climbing Bambusa species (B. merrilii and B. cornuta) and the climbing Cephalostachyum mindorense, all characterized by auricles having two horn-like appendages and a reduced number of florets in the spikelets, should be studied for comparison.
In 1993, Dransfield visited the Philippines and collected specimens of Schizostachyum and Dinochloa. She collected specimens from Baguio to Tuguegarao, Cagayan, practically travelling the whole of Luzon. She’s very much interested to study and possibly revised and ultimately solved some of the taxonomic problems on Philippine bamboos.
In 1995, Dransfield published “new species of Dinochloa (Giamineac-Bambusoideac) in Malesia and notes on the genus. Some of the species described were from the Philippines. Six new species of Dinochloa Buse, are described in the publication and these include D. malayana from Peninsular Malaysia, D. oblonga from Palawan (Philippines); D. harbala from Sulawesi (Indonesia). A new combination, D. palawanensis is proposed based on Schizostachyum palawanense Gamble from Palawan. The vegetative morphology and distribution of D. scandens are likewise revised.
Dransfield also studied the different bamboo species she collected from the Philippines. In October, 1997, she sent her article on a new genus from Luzon, based on Schizotachyum toppingii, to Kew, Bulletin. Also she wrote a paper on the revision of Schizoztachyum diffusum, Dinochloa diffusa and is now ready to be sent to Kew Bulletin (Personal communication)
Bamboo Propagation in the Philippines:
Bamboos can be propagated through seed or by vegetative means. Irregular supply of seeds for many common bamboo species has been the main reason for the high and continued dependence on vegetative propagation.
(a) Propagation by Seed:
This method of propagation depends on seed availability. Because of the tendency of most bamboos to flower gregariously, the availability of seed for propagation is unreliable. Hence, this method is very risky for large-scale establishment of plantations.
Some species do not produce seed (Bambusa blumeana, Bambusa vulgaris) and those which do so, often flower at long intervals varying from 30 to 70 years. Some species flower gregariously and then the parent all die (S. lumampao), some flower sporadically with or without parent plant deaths, and some species combine both patterns.
PCARRD (1991) reported that when bamboo seeds are produced, a large percentage are infertile and have very short viability.
In 1990, Sinohin conducted a preliminary observation on phonological events of flowering and fruiting of 7 bamboo species growing in different regions of the Philippines. The species studied were Bambusa blumeana (Kauayan tinik), Bambusa sp. (Bayog), Schizostachyum lumampao (Buho), Dendrocalamus latiflorus (Machiku), D. asper (Giant bamboo), Gigantochloa levis (Bolo) and G. alter (Kayali). Results showed that in all species, formation of flower buds started from October to November, and then the flowers bloomed continuously throughout the year. Maximum temperature and rainfall have negative correlation with bud formation and with minimum and maximum temperatures.
The setting of, fruits had highly significant correlation with maximum temperature.’ Rainfall and relative humidity have negative correlation with setting of fruits as well as with maturity and dropping of fruits. Minimum temperature was highly significantly correlated with fruit maturity and dropping. Preliminary surveys and observations showed that, among the flowering bamboo species, only Gigantochloa levis and Schizostachyum lumamopao produced viable seeds. Approximately 5 g. seeds of G. levis were collected and germinated. Fifty percent germination was obtained after 3 days in moist filter papers.
They were transplanted in small plastic bags. Several germinants were observed on the spike. Wildlings were also collected and transplanted in plastic bags for further observation. About 10 g seeds of S. lumampao were collected in Naguilian Road. Eighty percent germination was obtained for 2-8 days under moist filter paper. They were transplanted in plastic bags. Several germinants were observed on the spike and on the ground.
(b) Propagation by Tissue Culture
In 1986, the Institute of Plant Breeding obtained grant from the International Development Research Centre (IDRC) to work on bamboo tissue culture. In 1988, Zamora et. al., reported the results of their study entitled “Tissue culture of Dendrocalamus, Bambusa, Gigantochloa and Schizosachyum species of bamboo”. The materials they used were the nodal segments which were obtained from lateral shoots and ground corms. Results showed that the media, bleaching and contamination were the main problems encountered.
The decontamination procedure for shoots of Dendrocalamus latiflorus was unsuitable for Bambusa blumeana and the other species. Callus establishment from ground corms of B. vulgaris, G. levis and S. lumampao were also initiated. Browing was also prominent in these species as in D. latiflorus.
In 1992, Zamora et.al., published the results of their study entitled “Plant selection, Potting Mixes and Field Planting of Tissue culture derived plants of S. lumampao and D. strictus. Results showed that higher percentages of survival were obtained with acclimatized plantlets at 2 to 3 leaf stage, timing of potting during warmer months and use of sand- coir-dust or soil; sand; coir dust and soil; sand, compost, soil, soil from the creek side or soil; sand for initial establishment during the cooler months and warmer months of the year, respectively.
Growth of plantlets was favored in rich mixtures containing compost. Rhizomes were formed within 3 months of nursery care in soil, compost and soil- sand; compost. Potting mixtures were recommended for one-step and two-step potting out protocols. Tissue culture-derived plants of D. strictus planted in the field after 4, 6 and 8 months of nursery care showed that all plants could survive field planting at the onset of the rainy season with minimum care but growth was fastest with the older plants. Tissue culture derived plants of S. lumampao likewise survived field planting.
(c) Vegetative Propagation:
Over the years, many new vegetative propagation techniques have been developed tested and perfected. The vegetative parts that can be used for propagation are rhizome or offset, culm, branch and plant tissues. The rhizome or offset of propagating bamboo is applicable to species with loose clumps and are difficult to raise by culm cuttings such as ‘Amos’ (Schizostachyum lima), and ‘Buho’ (Schizostachyum lumampao).
The offset can be collected during the rainy season and if the planting site is near the source, the offset can be planted immediately in the field. However, it is better to raise ‘them first in plastic bags in the nursery before transplanting, to ensure better growth and survival in the field.
Among the vegetative parts, the one-node culm method is at present the most widely used because, it is the most economical and easiest to handle. This method is recommended for raising planting stocks of the ‘genera Bambusa, Dendrocalamus, and Gigantochloa. The cuttings should come from healthy one to two year old culms. Very young culms rot easily whereas older ones have higher mortality.
Manipula et al. (1990) conducted a study on the survival and growth of culm cuttings and whole culms of Kayali (Gigantochloa alter) as affected by age and culm portion. In culm cuttings study, results showed that 6 months old culm had the highest per cent bud-node sprouts survival at middle portion (43.33%) but not significantly different from the basal portion of the culm; the average number and height of shoots at the basal portion were significantly higher than at the top portion but not significantly different from the basal portion of the culm; the average number and height of shoots at the basal portion were significantly higher than at the top portion but not significantly different from the middle portion; the average number of leaves at basal portion (10:10) was significantly different from the middle and top portion, no significant differences were observed on the average number of length of roots at 3 portions of the culm.
In the whole culm study, the average height of shoots of 6-month old culm was significantly higher (6.89 cm) than 1-year old culm (1.58 cm). However, no significant differences were observed on the average number of shoots and average number of leaves per shoot of one whole culm of Kayali.
Propagation through branch cuttings is one of the most practical methods due to case of handling. Like culms, branches are stern material. Thick-walled species with stout branches are ideal like those of Bambusa and Dendrocalamus species. Generally, the basal and middle portions of the bamboo pole are good sources of cuttings.
A modification of the method is branch-marcot cutting. Although the method is similar to culm cutting, rooting is induced first by marcotting. The branch is cut into one node piece after the roots become apparent. The growth of the marcot plants can be enhanced by raising the plants in plastic bags using the same technique in culm cutting.
In 1989, Alfonso developed a new and practical method of propagating B. blumeana by branch marcottage. He did this by attaching transparent plastic bags filled with wet shagnum moss at the basal portion of branches attached to culms during the monsoon, months. After 2 weeks roots were visible through the plastic film.
Carino (1990) investigated the response of Bambusa vulgaris Schrad, to marcotting using compost, garden soil, manalo roots and each of these substrates combined with poly acrylamide (Broadleaf P4). Data on number of days to root emergence, length of roots and color as well as appearance of roots were observed and recorded.
Results showed that COMPOST + P4 had the earliest root emergence and longest root length, while MANALO ROOTS + P4 produced the most number of roots. Using of branch-cutting is advantageous because branches are removed from the parent culm. Which is not destroyed, branches are small and easy to handle and usually branches are plentiful.
In August, 1997, Decipulo conducted a training in Bucay, Abra, on bamboo propagation using branch cutting of giant bamboo (Dendrocalamus asper). The planting materials came from Malaybalay, Bukidnon where these kind of planting materials are being used (Personal communication).
Harvesting Methods/Techniques of Bamboo in the Philippines:
Large-scale plantation should be planned, taking into consideration the prevalent climatic conditions and making sure that a water source is easily accessible for irrigation purposes.
For areas with a marked dry season, the selection of drought-tolerant bamboos like Bambusa merriliana, Gigantochloa levis or Bambusa blumeanawill allow acceptable establishment and production. For areas with high and regular rainfall or a very short dry season, Schizostachyum lumampao, Dendrocalamus asper, Gigantochloa alter and Bambusa philippinensis more suitable.
Pastor (1992) reported that putting-up of a nursery is vital in establishing a bamboo plantation. In 1986, he started to plant direct planted cuttings of Bambusa blumeana. Out of the 4,000 cuttings he planted, only 1,000 survived. In 1987, he again tried direct planting. Only a little more than 2,000 out of 14,000 planting materials survived. Finally, the following year, he decided to establish a nursery and he attained a survival rate of 60%. Besides increasing the survival rate, they were able to reduce their input cost.
The pilot plantation in Magalang, Pampanga, was established in 1989 using nursery-raised cuttings. Grasses obtained from strip brushing were used as much to maintain moisture in the bamboo clump. Three hundred (300) grams of complete fertilizer were applied once every year for three consecutive years, after planting. Gonzales and Umali (1995) reported that direct planting of bamboo in a large-scale plantation is not feasible and practical. Bamboo planting stocks should be potted in the nursery for about six to eight months before out planting.
According to Virtucio (1996) the main objective of managing bamboo plantations is to maximize yield through sustained clump productivity. This is attainable through the application of appropriate silvicultural and harvesting techniques for specific bamboo species. Several factors must be considered to attain such objective and these include- nature of bamboo stands; site productivity relative to the species; specific end-use or utilization properties; and regenerative capacity of the given species.
Harvesting is one of the most important activities in a bamboo plantation not only because it leads to the production of culms that can be used or sold but also because, if carried out properly, it can improve future production in quantity and quality.
Ueda (1960) suggested that 1-3 year old bamboo must always be left in reserve while 4-year old culms (close to the ground) increase shoot production, reduce shoot mortality and deformed culms.
Virtucio and Tomboc (1990) studied the effect of 3 levels of thinning, 3 cutting age groups and 2 felling cycles on culm yield over a period of 10 years in natural stands of Schizostachyum lumampao. The levels of the 3 factors studied were – Thinning (heavy, moderate and light), cutting age (3 years and above, 4 years and above and 5 years and above); and felling cycle (every year and every 2 years). The results indicate the moderate thinning, cutting 3 years and above and felling cycle of 2 years is the optimum prescription for managing Schizostachyum lumampao natural stands.
Virtucio et al., (1992) studied the effect of 3 levels of thinning, 3 cutting age groups and 2 felling cycles on the culm yield of the natural stands of Bamboo blumeana Schultz. The levels of the 3 factors studied were- thinning (heavy, moderate and light); culm cutting age (3 years old and above, 4 years old and above and, 5 years old and above); felling cycle (every year and every 2 years). The results indicate that the application of light thinning; cutting of culms 4 years old and above; and a felling cycle of 2 years are the optimum prescriptions for managing Bambusa blumeana natural stands.