1. HARVESTING, THRESHING,
DRYING, STORING, AND
MILLING
OF RICE SEEDS
What is this lesson about?
This lesson is about the maturity indices of rice,
methods and systems of harvesting rice, threshing,
cleaning, drying, storing and milling including health
and safety precautions during harvesting.
2. At the end of the lesson, you should be able to:
1.Identify the maturity indices of rice;
2.Discuss the systems and methods of harvesting,
threshing, cleaning, and drying rice;
3.Identify the materials needed in harvesting,
threshing, cleaning, and drying;
4.Harvest, thresh, clean, and dry rice grain efficiently;
5.Observe health and safety precautions during
harvesting; and
6.Consider the value of proper harvesting, threshing,
drying, storing, and milling rice.
4. Harvesting is the process of
collecting the mature rice crop
from the field. It starts from
cutting, stacking, handling,
threshing, cleaning and
hauling. According to some
experts great losses in rice
production happen during
harvesting and other post
harvest activities. Our definite
goal then is to maximize our
yield and minimize grain losses.
5. -Like other cultural
management of rice, correct
timing of harvesting is crucial in
order to have a good quality of
harvest and to prevent crop
losses.
- Grain losses may occur from
the damage caused by rats,
birds, and crop lodging and
shattering during windy days.
- Proper timing of harvesting
ensures good grain quality and
high market value.
6. - Too early harvesting will result
in higher percentage of unfilled
or immature grains which will
result in higher grain breakage
and lower milling recovery.
- Too late harvesting will lead to
excessive grain shattering losses
and increased breakage of rice.
- Timing of harvesting also
affects drying, storing, and even
the germination potential of
rice seeds.
7. -We can determine the
best time to harvest
based on the maturity
date of a given variety or
by examining the panicle
if all the grains are
ripened.
- Rice should be
harvested when 80-85
percent of the grains
turned yellow.
8. - The grain moisture
content ideally is
between 20-25% MC.
-If the crop is too dry,
when these are
rewetted, they break
when milled resulting
in low quality and low
milling recovery.
9. -In dry season harvest, an optimum time of harvest 28 - 35
days after heading gives best grain germination and head rice.
- In wet season harvest, optimum time is 32 - 38 days after
heading.
10. Methods of Harvesting Rice
1.Manual is the method of harvesting rice with the use
of sickle and scythe.
2. Mechanical is the method of harvesting rice with the
use of a reaper or combine harvesters.
11. Whatever method is used in harvesting always take note of the
following:
•Harvest at the right time and moisture content (20-25% MC). Too early
harvesting results in difficulty in separating grains from the panicle and
immature grains from the head will be ground during milling.
•Avoid delays in threshing after harvesting, within an overnight that the
harvested rice is stacked specially if it is wet, the grain quality is
affected.
12. •Use the proper machine in threshing.
There are some machines that allow lots of
grain to go with the hay during threshing.
•Clean the grain properly after threshing.
13. Harvesting could be done through the following:
•Manual harvesting and stacking, followed by
threshing and cleaning by hand. This includes the use
of traditional tools for threshing such as racks, simple
treadle threshers and animals for trampling. This
method has been a thing of the past due to intensive
farm mechanization.
14. •Manual harvesting followed by threshing and cleaning with a
threshing machine. All threshing machine now includes a
simultaneous cleaning of the grains.
•Mechanical harvesting using a rice reaper and threshing by a
threshing machine and by using a combine harvester. The
combine harvester will combine all operations: cutting,
handling, threshing ,and cleaning.
15. List of advantages and disadvantages of common harvesting system
Method Description Advantages Disadvantages
1. Manual harvesting
and threshing
Cutting, stacking,
bundling, handling
and piling by hand
Threshing by
beating
cleaning by
winnowing
Efficient
Most effective in
lodged crop
Less weather
dependent
High labor cost,
skill dependent
Susceptible to
grain damage
Winnowing/cleanin
g necessary
2. Manual harvesting
and threshing/cleaning
by machine
Cutting and
stacking by hand
Threshing by
machine
More effective in
wet season harvest,
wet crop conditions
Higher capacity
than manual
Lower labor
requirements
Higher capital cost
Dependency on
availability of
contractor
Less dependent on
field size
3. Standard combine
harvest
Harvests, threshes,
and cleans crop
mechanically
Transport
harvested grains in
convenient area.
High output,
timelines attained
Produces clean
grain
Spread straw back
in the field, which
will ensure a good
source of organic
material to the
farm.
Higher cost
Less effective in
partially lodged
crop
16. Note:
Avoid burning of rice material wastes such
as the hays, hulls, and other materials.
Farm wastes burning is regarded as one of
the big contributors to global warming.
17. Developing Mastery:
1. What is harvesting?
2. What are the factors to consider
in harvesting rice crop?
3. What is the difference of manual
and mechanical harvesting?
