Researchers Find Ways to Improve Productivity of Kawayan Tinik (Bamboo)
Is it possible for a previously unmanaged bamboo plantation and natural stands to improve productivity and sustainably produce quality poles and shoots.
The answer is yes, says Dr. Stanley C. Malab, a scientist and the vice president for research, extension and agribusiness affairs of the Mariano Marcos State University (MMSU) in Batac City, Ilocos Norte.
Dr. Malab is upbeat with the results of their five-year research titled “Improving Productivity of Unmanaged Kawayan Tinik (Bambusa blumeana Schultes F.) Plantation for Poles and Shoots” which identified the optimal clump management practices necessary to improve productivity of previously unmanaged bamboo plantations as well as natural stands.
Dr. Malab conducted the research together with Charlie B. Batin, a research assistant from MMSU; Beatriz S. Malab, an associate professor also from MMSU; Marina Alipon, a scientist from Forest Products Research and Development Institute (FPRDI) in Los Banos, Laguna; and David J. Midmore, a professor from Central Queensland University in Australia.
Conducted in an unmanaged 2.5-hectare (ha) bamboo plantation in MMSU from 2001-2006, the research was a collaboration of MMSU, Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD) and the Australian Center for International Agricultural Research (ACIAR). It was also conducted within the framework of the ACIAR and PCARRD project called “Australia-Philippines Partnership for Bamboo for Sustainable Regional Development.”
KAWAYAN TINIK IN Focus
Dr. Malab and his team focused their study on Kawayan tinik which dominates the 62 recorded species of bamboo growing in the Philippines. Twenty-eight of these arc found in I locos.
The PCARRD’s Bamboo Information Network describes Kawayan tinik as clump forming, has spiny branches, and produces clumps that grow to a maximum of 20 centimeters (cm) in diameter with internodes of up to 60 cm long. It reaches up to 20 meters high and has superior strength and durability.
Kawayan tinik regenerates faster than wood, has a very short growth cycle, and can be harvested four years after planting. As one of the economically important species of bamboo, it is considered as the best species for shoot production in the Philippines. Its other uses include furniture, handicraft, construction, food, biofuel, and environmental protection.
As the supply of quality raw materials diminishes due to the intensive utilization and increasing demand, the researchers emphasize the need to encourage more people to engage in bamboo production and establishment of large bamboo plantations to meet the demand.
As of now, existing commercial plantations could not meet the demand of various industries. This makes the natural stands as the most logical sources of raw materials. Researchers say that if given the right management, natural stands could produce enough poles and shoots for the local market.
The research team also urges for a definite or strong policy that regulates the utilization of bamboo in the region where an estimate of 303,160 natural clumps of B. blumeana is exploited annually. In Batac, however, cutting, harvesting or gathering of bamboo shoot by any means except for research purposes is prohibited.
THE EXPERIMENT
Dr. Malab and his team came up with thirteen treatments (see Table 1), with each plot composed of two clumps replicated in three blocks. All in all, there were seventy-eight clumps identified for the study.
Prior to the study, the researchers removed all poles older than four years including those that are dead, broken, and defective. This is to provide wider growing space between the clumps and for easier harvesting of poles and shoots.
The researchers then applied plantation management practices which included fertilizer treatments such as application of 250 kg nitrogen (N) per hectare in split (first on the onset of rainy season and the second at two months after the first); organic matter treatments such as application of 0.2 cubic meters (m’) of chicken manure and 0.4 m3 sawdust annually per clump before rainy season; mulching with bamboo leaves and other debris found around the clump; and installation of drip irrigation system.
The culms were harvested each year and these were sent to FPRDI for analysis of physical and chemical properties. On the other hand, the testing on the density of poles was conducted at MMSU on the fifth year of the experiment.
RESULTS
The researchers found out that water availability was apparently very important to the growth and emergence of new shoots. They have observed that shoot emerged right after the first splash of the rain, which resulted in its robust growth. Compared to the clumps that did not receive any silvicultural treatment, the clumps that had undergone cleaning, irrigation, and fertilizer application had better performance.
In addition, the application of silvicultural treatments improved the diameter and size of poles and thickness of culms compared to the do nothing clumps.
However, the researchers observed that fertilizer application and mulching without irrigation did not improve shoot production. This, they said, proves that most shoots usually emerge at the onset of the rainy season and very few on the dry season when soil moisture is at its lowest.
The researchers also observed that it was more advantageous to harvest for whatever purposes the three-year old and older poles than to keep them for shoot production. This is because their findings showed that the one-year-old mother culms produced, regardless of the treatment, more shoots every year than the two-year-old and older culms.
Succeeding activities such as harvesting of shoots and poles were also rendered more convenient than without doing anything to the clumps because definite numbers of shoots and poles were assigned every year to be harvested.
In terms of strength, it shows that poles aged three years and above were stronger and were more suited for construction purposes. The study shows that pole strength increases as they mature from three to four years old and above. Therefore, they recommend harvesting at this age as far as sustainability and income generation are concerned.
POTENTIAL HARVEST
Given a one-hectare bamboo plantation spaced at 7 m x 7 m, there will be a total of 204 clumps per hectare.
Among the treatment combinations, the 4-4-4 and the 4-4-4-4 are the most preferred for pole production because both do not only meet the culm thickness requirement for manufacture of bamboo tiles, but also produce higher potential number of shoots. The latter would yield 4 poles per clump or a total harvest of 816 poles per hectare per year.
For shoot production, the 4-4-4-4 treatment would yield an average of 6 shoots per clump. These are produced by the 1, 2-, and 3-year old poles growing every year. Dr. Malab said that if 4 shoots will be allowed to grow for the next harvest of poles, 2 will be left for shoot production. This would give 408 shoots per hectare per year.
Table 1. Experimental Treatments
Treatment No. Description
1 Control – continuous irrigation with mulch, organic matter and fertilizer 4-4-4 (Successive numbers indicate the number of one, two, three or more year old culms in each clump, counted just before the shoot season.)
2 Dry – no irrigation with mulch, organic matter and fertilizer 4-4-4
3 Strategic irrigation, with mulch, organic matter and fertilizer 4-4-4
4 No fertilizer with mulch and irrigation 4-4-4
5 No fertilizer and mulch but with irrigation 4-4-4
6 Continuous irrigation with mulch, organic matter and fertilizer 3-3-3
7 Continuous irrigation with mulch, organic matter and fertilizer 3-3-3-3
8 Continuous irrigation with mulch, organic matter and fertilizer 4-4-4-4
9 Keep all culms but harvest a113 years old, with continuous irrigation with mulch, organic matter and fertilizer
10 Continuous irrigation with mulch, organic matter and fertilizer 3-3
11 Continuous irrigation and fertilizer 8 culms/2-year cycle (4-4 for first year)
12 Cleaning only, no harvesting but with fertilizer application and mulch
13 Do nothing