The different steps of harvesting and transport operations can be identified in the following flowchart:
Smaller numbers of palms can be felled by axe or with a two-man saw. However, due to the abrasive effect of the sclerenchymatic fibres in the bundles, the saw has to be resharpened often and the procedure of felling is tedious and slow. For clear-felling it is advisable to use a chain-saw with a 60 cm guidebar and chipperchain. A two-man team (operator and assistant), equipped with chain-saw, axe, machete, wedges, repair kit, and medical kit, needs 2 – 3 working days (4 – 6 man-days) to fell one hectare, thus yielding about 90 m3 of coconut stems. The basic felling principles are shown in Figure 12.
Fig. 12: Felling of coconut palms
Source: PCA, 1977
| Important | ||
| Fell all palms in one direction in order to facilitate their removal! |
The palms should be felled as close to the ground as possible in order to reduce the size of the stumps left behind. With larger stumps the danger of rhinoceros beetle infestation increases. The lower the stumps are, the easier they will be covered by the cover crop (usually a legume) and hence decay, thus adding to the fertilization of the plantation.
If the stumps are to be removed as well, the palm has to be toppled by heavy equipment, e.g. a bulldozer. This can be done either by bulldozing through the roots, previous manual cutting of the roots (Figure 13), or by just toppling the palms with a bulldozer. However, if the palm is felled in this way (Photo 27), additional costs arise in disposal of stumps (useless for further processing) and in levelling of the plantation. Therefore, it is recommended to leave the stumps in the ground and plant the new palms between the old rows.
Fig. 13: Bulldozing through palm roots
Source: FAO, 1985
Photo 27: Coconut palm stems after toppling
After felling, the top portion of the palm (3 m below crown) is to be cut off. The method of hauling depends on the type of equipment available as well as on the scale of operation. If the stems are to be pulled out by draught animals (oxen, donkey, horse, water-buffalo), the stems have to be cross-cut (bucked) to a shorter length at the plantation in order to reduce the load for the animals (Figure 14). The length of the logs cut depends on their later use. The logs must be marked on their lower end after bucking in accordance with their position in the stem, i.e. bottom log (1), middle log (2), top log (3) etc., because the quality of lumber also depends on its vertical position in the stem. The marking facilitates later grading (Figure 15).
Fig. 14: Skidding behind horse
Source: FAO, 1985
Fig. 15: Marking of logs in field
Source: FAO, 1985
If agricultural tractors are available, two methods can be applied for skidding:
Method 1:
The tractor is stationary at the collecting point. The entire stems are pulled out by means of a winch (yarding method) connected to the tractor's power take-off.
Disadvantage: The stem ploughs through the ground while being pulled, it collects mud and grit, which facilitates decay and makes later sawing more difficult.
Method 2:
The entire stem is pulled by the tractor, bottom first, with the help of a chain and a skidding bar fitted to the hydraulic lift of the tractor. The skidding bar can easily be manufactured locally from mild steel. For lifting the stem, a normal chain will do (Figures 16, 17).
Advantage: The stem is lifted at the front end, and only the top portion slides over the ground and collects dirt.
Fig. 16: Skidding bar
Source: Jensen, 1981
Fig. 17: Skidding by tractor
Source: Jensen, 1981
At the collecting point or landing, the stems are cross-cut (bucked) according to the length required, usually 5 – 6 m (Figure 18). The length depends on the end-use of the timber. It is obvious that in order to achieve highest recovery, a stem with strong sweep is cross-cut into shorter logs than one with a straight bole.
In situations where the stems are to be used as transmission poles, only straight, sound palms should be selected and cut to the appropriate length.
Fig. 18: Bucking of coconut palm stems
Source: PCA, 1977
The means of transportation to the sawmill depends on the amount of stems to be transported and on the distance to be covered. Oxen or buffalo driven carts, flatbed trucks, or four-wheel bunk-trailers towed by agricultural tractors can be used. Loading can be done with the help of an agricultural tractor with a forklift. Another possibility is the construction of a slide, made from shorter upper ends of the coconut palm stem, leading to the trailer platform. The logs can then be pulled over this slide with ropes and the help of draught animals stationed on the opposite side of the vehicle.
| Important |
| Swift removal of the palms from the plantation and landing is essential in order to reduce the danger of decay! |
The unloading at the log-yard can be done manually, over a slide made of smaller coconut logs, or with the help of a forklift tractor. The log-yard should be dry and well drained. All vegetation should be removed and the area either gravelled or cemented. This is important to reduce the danger of insect and fungal attack during storage. Also, in order to minimize this danger, the storage time in the log-yard should be as short as possible. A water tap should be close by to allow the washing off of any dirt and grit of the logs before sawing.
| Remember |
| Logs are easier sawn when still wet. Dirty logs blunt the tools faster. |
