A low-cost hand-operated seeder for hill seeding pre-germinated rice on to puddled soils

Vu Dinh Phien

Date

1990

Abstract

The conventional reciprocating-cell-bar-type seed metering was developed successfully for hill seedling pre-germinated rice onto puddle soils. The three modifications are as follows: 1. The cylindrical hole was extended towards the rear margin adding a semi-elliptically shaped canal-like depression sloping gently from the upper end towards the mid-bottom sector of the hole in order to minimize seed damage. 2. A reciprocating finger located just above the cell moves in opposite direction with the metering bar in order to prevent bridge of sprouted and wet seed clinging together by the entanglement of its roots and also to direct the seed into the cell, resulting in improved and more consistent cell filling. 3. A gap was established at the mechanism connecting the metering bar and operating handle of the seeder, making the cell to stop momentarily when exposed to seed mass while the the finger keeps moving over the cell to improve cell filling. Consequently, this improved metering device gave better seeding quality, seeding accuracy of 97.12% and seed damage of 1.13% as compared with 86.96% and 14.40% respectively from the conventional metering device of the same type. By laboratory experiments, the main design parameters of this improved metering device were determined on the basis of highest seeding accuracy and lowest seed damage responses. The optimum level of combination of parameters for seeding rate of 8-14 seeds/hill was found as follows: depth of round cell (or thickness of metering bar), 7mm; diameter of cell, 10-13 mm; clearance between agitating finger end and top surface of cell, 4.5-7.0 mm; stroke of metering bar, 19-25 mm; length of additional sloping canal, 19-22 mm; and speed of metering bar < 70 cycles/min. Seeding quality is almost not dependent on seed level in hopper. With the improved metering device, a low-cost hand-operated seeder for hill seeding pre-germinated rice onto puddle soils was developed. The prototype was tested and evaluated in laboratory and field conditions. Test results indicate that the seeder is simple, easy to fabricate and operate, and able to drop even up to 72-hour old pre-germinated seeds in distinct hills. The following are some main specifications: number of rows, 6; row spacing, 20 mm; hill spacing, adjustable; seeding rate, adjustable within 8-14 seeds/hill; field capacity, about 500 m2/hour; seeding accuracy, about 94%; seed damage, about 1.4%; hill-seed grouping, 89%; weight,10 kg; construction materials, wood and sheet metal.

Document Type

Master Thesis

Language

English

LC Subject

Rice

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 995 1990 A2 V8

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