Nature and Farming

Thresher options for the farmers

With the rise in popularity of the axial flow threshers in the 70's, various sectors of society have since benefitted -- from the small farmer to the big farmer to the non-farmer-worker-turned-thresher-operator to the farm machine manufacturer to the money-lender-businessman. Currently, farmers have a wide range of threshing system options from which to choose depending on the volume of palay to be threshed, available capital and labor resources, availability of threshers for rent and the existing socioeconomic structures and systems. The threshing can be done by the farmer using the reliable and almost zero-cost hampas method, by paying for the threshing service or by pooling resources of a farmer group to purchase a thresher unit.

Basic data or, existing thresher models are presented on the other side of this sheet. This information may be helpful to farmers or groups of farmers in their initial assessment of existing threshers (as taken from IRRI and UPLB handouts). As of 1989, prices of threshers range from P2,000 to P6,000 depending on size and model.

Thresher options for the farmers

SOME BASIC INFORMATION ON EXISTING PALAY THRESHERS MODELS

THRESHER MODEL	RATED CAPACITY (kg/hr)	POWER REQUIREMENT	LABOR REQUIREMENT	TRANSPORT ABILITY	OTHER FEATURES
Pedal thresher	120	foot-powered	2 persons	carried by 2 men	hold-on threshing
Portable thresher	300-600	5 hp engine	2-3 persons	carried by 2 men	throw-in or hold on threshing with air winnowing
Axial flow thresher
- TH7	500	7 hp engine	3-4 persons	carried by 4 men	throw-in threshing with an air and screen cleaning mechanism
- TH8	1000	10 hp engine	3-4 persons	pulled by power tiller, light truck or animal	throw-in threshing with an air and double-screen cleaning system
Thresher/ Sheller	1000-1500 (palay) 500 (corn)	16 hp engine	3-4 persons	pulled by power tiller, light truck or animal	modification of axial flow threshers to make applicable to both palay threshing and corn shelling

For details contact:

1. Agricultural Engineering Department International Rice Research Institute Los Ba Laguna

2. Agricultural Mechanization Development Program College of Engineering and Agro-lndustrial Technology University of the Philippines Los Ba Laguna

3. Agricultural Engineering Division Bureau of Plant Industry San Andres, Malate, Manila.

Dryers: investment for the rainy days

WHY DRYERS (especially for the rainy season)?

1. Farmers can avoid selling wet palay (unmilled rice) at low prices.

2. Higher milling recoveries are obtained from properly dried grain.

3. Farmers can better save their seeds for the next planting (common practices of using electric fans and frying pans to dry seeds on rainy days are costly and inefficient).

4. Dryers require less space compared to sundrying.

5. Most dryer designs make use of farm wastes for fuel.

Dryers

As far as small farmers are concerned, dryers are for rainy season use. However, if they are paying for the use of the drying pavement and hiring workers to mix and haul the grains, dryers may still prove more economical even in the dry season.

LIMITATIONS TO USING DRYERS AND WHAT MAY BE DONE:

1. Entails higher operational and investment cost compared to sundrying.

Dryers cost from P2000 - P40,0000 per unit. The investment cost per farmer may be decreased if a group or cooperative owns the dryer. The dryer can also be rented out to generate income. A drying cost of about P4.45/cavan (1 cavan = 50 kg) has been calculated for one dryer model (1988 estimates).

2. Limited grain-drying capacity. If there is need for drying large volumes, the multistage drying technique may be used. This involves first drying the grain to 18-20% moisture content (MC) and then drying it a second time to the required13-14%MC. This technique may be used because simply lowering the grain MC to 18-20% greatly delays grain deterioration.

If the task is to dry only 2-40 cavans of grain per day, then the existing dryer models may be used without resorting to the multistage drying technique.

INFORMATION ON SOME EXISTING PALAY DRYER MODELS

MODEL	RATED CAPACITY*	POWER/FUEL REQUIREMENT	FEATURES	DESIGN/ PROMOTED BY
UPLB Multipurpose Dryer	2-12 cavans per batch/day	no motor engine required; uses charcoal rice hulls, wood chips and other farm wastes for the burner	originally designed for copra drying but adapted for grains drying	UPLB
CPV Rotary Flash Dryer	3-4 cavans per hour	1.5 kw motor to drive dryer cylinder; 2 kw motor to drive blower; uses rice hull for the burner	multistage dryer; a smaller, simplified version of MA- IRRI rotary dryer	Central Philippines University College of Agriculture (CPU-CA)
IRRI Batch Dryer	20 cavans in 4 to 6 hours	3 hp gasoline engine or 2 hp electric motor to drive blower; uses kerosene or rice hull for the burner	compact and portable; automatic safety device to shut off burner assembly	IRRI
UPLB Flatbed Dryer	40 cavans in 8 hours	5 hp gasoline engine or 3 hp electric motor to drive blower; uses kerosene or rice hull for the burner	compact and portable; automatic safety device to shut off burner assembly	UPLB

*One cavan = 50 kg.

For details on technical design, contact:

1. College of Engineering and Agro-lndustrial Technology University of the Philippines at Los BaCollege, Laguna, Philippines

2. Agricultural Engineering Department International Rice Research Institute (IRRI) Los Ba Laguna, Philippines

3. Central Philippines University College of Agriculture lloilo, Philippines

Slicer for sesbania and other green manures

The slicer is an indigenous blade-toothed, animal-drawn weed chopper which has been used by farmers in Northern Luzon for generations. Since rice was cropped only once a year, the slicer was originally used to cut viny and tall weeds that grew during the long fallow period after rice harvest. The slits in the soil made by the slicer also facilitated plowing.

One objection to the use of green manure crops by many farmers is the difficulty of incorporating the biomass into the soil. The slicer, with its capability of handling large amounts of biomass produced during long fallow periods, should help overcome that difficulty. The slicer could help to make green manuring (the practice of growing and incorporating plant biomass for fertilizer) more attractive to farmers.

USING THE SLICER:

The slicer, with a weight on the board, is pulled by a carabao. As the carabao steps forward, the plants are pressed down. The front board of the slicer further presses the green manure crop to the ground and the blades then cut the biomass into pieces. The slicer is pulled ever the green manure several times depending upon the amount and thickness of the biomass. If the crop growth is dense, a cries-cross passing may be needed to finely chop the biomass.

Using the slicer

LIMITATIONS:

· If the green manure is too tall, it may be difficult for the carabao to pass through the field.

· If the stalks or stems become woody, the slicer may not be able to cut the stems very well.

MATERIALS NEEDED FOR SLICER:

Farmers can easily make a slicer with local materials. The blades can be ordered from blacksmiths at P25 (5 blades are needed). The wooden board that holds the blade would cost only P50 to P80. The draw bar can be made from any hard wood like kakawate (Gliricidia septum) or coffee branches.

The slicer design illustrated here is the same as that used by farmers in Northern Luzon with the exception of one extension hole in each of the five blades The original design haz only one hole in one end of each blade. IIRR engineers added the other hole to double the life of the blades. Only one end of each blade is attached to the slicer. The other end is worn down by constant contact with the soil. When that end is worn down almost to the hole, the blade is turned around. The end originally attached to the board now serves as the slicing end of the blade.