1. Time and stage of harvest and harvesting techniques for rice
Next
End

2. Time and stage of harvest and harvesting techniques for rice
Abstract: Identification of maturity and correct stage of harvest is one of the most important aspects in rice cultivation. Premature harvest of rice affects the quality due to ill-filled and chaffy grains and over matured harvest induces shattering. Some of the factors considered while deciding time of harvest of rice are economic part aimed, products utility and post harvest storage.
Previous
Next
End

3. Time and stage of harvest and harvesting techniques for rice
Manual and mechanical methods of harvesting are the two methods of harvesting of rice crop, decided depending upon the purpose, time and labour availability.
Though manual methods are used for many decades in developing countries, mechanical methods of rice harvest not only resolve the present day labour crisis, but also, cost and time.
Previous
Next
End

4. Time and stage of harvest and harvesting techniques for rice
Learning objectives:
To learn the maturity symptoms and of various criteria of harvesting rice crop.
To study the harvesting time, stage and methods; and machineries available for harvesting of rice.
Introduction:
Rice is the most important food crop of the world.
Higher production and quality of rice not only rely on cultivation but also, harvesting of rice.
Right time of rice crop harvest is one of the most important factors to get higher yield and good quality produce
Previous
Next
End

5. Time and stage of harvest and harvesting techniques for rice
Premature or delayed harvest often adversely affects quality of the produce.
Physiological and harvest maturities are two maturity judgments made in rice crop to decide the harvesting time.
At physiological maturity (during which the translocation of photosynthates stops), the rice panicles completely matures at top and few grains at bottom at immature stage.
Previous
Next
End

6. Time and stage of harvest and harvesting techniques for rice
Whereas, during harvest maturity the crop looks dried appearance due to drying of all most all the leaves.
Harvesting may be the most important operation in rice and the farmers are following traditional techniques for harvesting rice, but new equipments and machineries are introduced to nullify the labour problems.
Previous
Next
End

7. Time and stage of harvest and harvesting techniques for rice
I. TIME OF HARVESTING
Yields of rice crop are expected high when it is harvested the economic product is at its optimal quantity and quality.
Ideal time to harvest of rice depends on a number of factors, including the economic part, utilization of the product and post harvest storage.
Previous
Next
End

8. Time and stage of harvest and harvesting techniques for rice
Economic part
The economic product in rice is mainly grain and straw is also used for cattle.
Rice is to be harvested when the grain is fully matured and filled so as to get maximum quality and quantity.
Utilization
Rice grain is either used as grain (for human food) or seed. If the produce is used for grain, harvesting date can have flexibility but, not for seed.
Immature seeds spoil germination whereas, over dried seeds form splitting and cause germination.
Previous
Next
End

9. Time and stage of harvest and harvesting techniques for rice
Post harvest storage Rice after harvest need to threshed and dried to safe moisture (<14%). Maturity Rice can be harvested at physiological maturity or at harvest maturity or storage maturity depends on situation or need of produce. Physiological maturity Physiological maturity refers to a developmental stage after which no further increase in drymatter in the economic part
Previous
Next
End

10. Time and stage of harvest and harvesting techniques for rice
In rice, moisture content of grains is very high during milking stage and it gradually deceases due to accumulation of photosynthates. Sudden fall of moisture content from 40% to 20% is an indication of attaining physiological maturity. The grains at this stage are of hard dough consistency.
Physiological maturity symptom of rice
Previous
Next
End

11. Time and stage of harvest and harvesting techniques for rice
If grain is harvested prior to its physiological maturity, it would have low drymatter, poor quality and will shrivel upon drying.
Golden yellow colour of the grain and senescence of lower leaves are the key symptoms of physiological maturity of rice.
Previous
Next
End

12. Time and stage of harvest and harvesting techniques for rice
Harvest maturity
Harvest maturity for a crop is when the product of interest is at best quality and maximum yield.
Harvest maturity generally occurs 7-10 days after physiological maturity in rice.
The important process during this period is loss of moisture from the plants and grains.
Hard and yellow coloured grains, golden yellowing of leaves are the important symptoms of harvest maturity in rice.
Previous
Next
End

13. Time and stage of harvest and harvesting techniques for rice
Harvest maturity symptoms of rice
Previous
Next
End

14. Time and stage of harvest and harvesting techniques for rice
Storage maturity
When there is no scope or chance for post harvest drying, the crop is to be harvested at a stage where it can be directly stored.
For grains, <14% moisture content is advocated.
Generally, in rice, harvest maturity is advocated because; it avoids both immature of grains (due to physiological maturity) and splitting of grains (due to storage maturity).
Previous
Next
End

15. Time and stage of harvest and harvesting techniques for rice
II. STAGE OF HARVEST Determination of harvesting date is easier for determinate crops like rice. The following are the criteria for harvesting of rice crop days after flowering Less than 4-9% green grains in a panicle Milky grains in a panicle - less than 1% Moisture content of grains - less than 20% About 80% of panicles are straw coloured and grains in lower portion of panicle is in hard dough stage.
Previous
Next
End

16. Time and stage of harvest and harvesting techniques for rice
III. HARVESTING TECHNIQUES Two methods are followed in different countries for harvesting of rice crop, largely depending on timely labour availability and costs associated with harvesting. Manual harvesting of rice is still the major method of harvest in developing countries since the combined harvesters may spoils the straw, while mechanized harvesting dominates in developed countries and river basins where the transplanting and harvesting of rice in large areas at once
Previous
Next
End

17. Time and stage of harvest and harvesting techniques for rice
Manual harvesting
Manual harvesting of rice is most common in under-developed and developing countries.
The sickle is the most common and the major traditional tool for harvesting.
The output is low and the effort required for operation is high.
Previous
Next
End

18. Time and stage of harvest and harvesting techniques for rice
Manual harvesting of rice
Previous
Next
End

19. Time and stage of harvest and harvesting techniques for rice
Mechanized harvesting
Machines are available for harvesting rice.  The machine cuts the paddy stubbles and laid down the harvested crop in the field.
Later, the harvested rice stem should be bundled and stacked in a dry place if not threshed immediately.
Combine harvester
The combine harvester combines operations such as cutting, handling, threshing and cleaning.
Previous
Next
End

20. Time and stage of harvest and harvesting techniques for rice
The combine paddy harvester can harvest about 4 ha/day and can be operated in fields as small as 30 cents.
It needs only a driver and helper to operate the machine. 
There is no wastage of grains and the cost of operation is equal to the wages paid for manual labour. 
Combine harvesting of rice has been accepted by farmers in regions with labour shortage during harvesting period. These are more suitable for custom hire service.
Previous
Next
End

21. Time and stage of harvest and harvesting techniques for rice
Combine harvester
Previous
Next
End

22. Time and stage of harvest and harvesting techniques for rice
Summary: The main factors considered for deciding for time of harvesting are the economic part, utilization of the product and post harvest storage. Main economic parts in rice are grain and straw and harvesting after maturity provides good quality of grains. Rice can be harvested at physiological maturity or at harvest maturity or storage maturity depends on situation or need of produce.
Previous
Next
End

23. Time and stage of harvest and harvesting techniques for rice
Golden yellow colour of the grain and senescence of lower leaves are the key symptoms of physiological maturity of rice.
Hard and yellow coloured grains, golden yellowing of leaves are the important symptoms of harvest maturity in rice.
Rice grains are stored at <14% moisture content.
Previous
Next
End

24. Time and stage of harvest and harvesting techniques for rice
About 80% of panicles are straw coloured and grains in lower portion of panicle is in hard dough stage is the main symptom of harvest of rice.
Harvesting of rice is done in two methods, viz., manual and mechanical means.
Sickle is the most prominent tool used for harvesting rice manually; whereas, combined harvesters do the job in mechanical means.
Previous
Next
End

25. Time and stage of harvest and harvesting techniques for rice
Assessment:
1.Golden yellow colour of the grain and senescence of lower leaves indicates physiological maturity of rice (True/False).
2.Hard and yellow coloured grains, golden yellowing of leaves are the important symptoms of storage maturity in rice (True/False).
3.Rice grains are stored at <10% moisture content. (True/False).
4.Sickle is the most prominent tool used for harvesting rice manually (True/False).
5.Combined harvesters are used mainly for harvesting rice in mechanical means (True/False).
Previous
Next
End

26. Time and stage of harvest and harvesting techniques for rice
References:
Rajendra Prasad, A text book of Rice Agronomy. Jain Brothers, New Delhi.
Nakra, C.P Farm machinery and equipments. Dhanpati Rai and Sons, New Delhi.
Reddy, S.R Principles of crop production. Kalyani Publisher, Ludhiana.
Yellamanda Reddy, T. and G.H. Sankara Reddi Principles of Agronomy. Kalyani Publisher, Ludhiana.
Previous