Rice Production Technology

Varieties:
54 HYV and 4 Hybrid varieties has been discovered from BRRI. The latest HYV variety is BRRI DHAN 55 from BRRI. This variety has been approved by the technical committee. It is hoped to get the approval of National Seed Board within a few days.

Selecting the Appropriate Season:

Seasons in Bangldesh:

There are three seasons for the cultivation of rice in Bangladesh. They are namely Aush, Aman and Boro. They are discussed below:

         

Aush Season:

In aush season rice can be cultivated by broadcasting and transplanting method. The Suitable time for sowing seed is 15-30 Chaitra (March 29 to April 13). Rice cultivated in this season is not photosensitive. Life time is shortest than the others. Only 120 days. For transplanting the age of the rice will be 25-30 days.  Popular varieties of aush season is BR-1(Chandina), BR-2 (Mala), BR-3 (Biplab), BRRI Dhan-27 etc.

Aman Season:

Life time of aman rice is 140 days. Some transplanting aman rice are photosensitive, some are insensitive and some are partially sensitive. On the basis of this factor the time of sowing and transplanting can be forwarded or back warded depending on the variety. Mentioned that the varieties of transplanting aman rice are sown from 15 Ashar to 15 Srabon (June 29 to July 30) and the seedlings of 25-30 days age are transplanted from 15 Srabon to 15 Vadro (July 30 to August 30).

It is proved that if seeds are sown in 15-30 Ashar (June 29 to July 14) and transplanted from 15-30 Srabon (July 30 to August 14) the yield will be the highest. The popular aman varieties are BRRI DHAN-32, BRRI DHAN- 33, BRRI DHAN- 40, BRRI DHAN- 41 etc.

Boro Season:

Life time of boro rice is 160 days. The varieties with lifetime less than 150 days  are sown in the beginning of Agrahayan (November 15) and the varieties with more than 150 days life time is sown after 20 Kartik (November 4). The sowing must be completed by 15 Magh (January 28). Because later than that the yield may be lesser. The popular varieties are BRRI DHAN-28, BRRI DHAN-29, BRRI DHAN-47 etc.

Sorting of Quality Seed:

Disease free, clean, vigor that means quality seed is must for expecting a good yield. To sort out the good seeds urea-water solution at 1.5:40 ratio is used. Dipping the seeds in the solution the healthy seeds are drowned at the bottom and the quality less seeds remain floating at the surface.

Seed Treatment:

Prior to seeding in the seedbed seeds should be treated with Agrosan GN 1.5gm/kg seed or Granosan M 1g/kg seed.

Preparation of Seed Bed:

500 square meters nursery bed is required to transplant in one hectare of land. The seed bed is produced in 4 ways- Dry seedbed, Wet seedbed, Floating seedbed and Dapog seedbed.  

Dry Seedbed:

For dry nursery bed the land should be prepared by several plows and cross plows along with laddering to break the clods and level the soil.

Wet Seedbed:

Wet seed bed is mostly used in Bangladesh. Loamy soil and clayey soil is perfect for wet seed bed. The land is water logged for 7-10 days. After rotting of weeds and crop residues the land is paddled by several plow and cross plow followed by laddering to level the soil.

Dapog Seedbed:

When there is no chance to make a dry or wet seedbed due to flood or other circumstances dapog method is used. A concrete floor, plastic sheets, banana leaves without mid rib etc. are used and surrounded by banana trunks, plastered by mud to retain water and protect seeds from spreading out. Water should be sprinkled at least a day to protect seeds from drying out.

Floating Seedbed:

Suitable for flood affected condition. A floating platform is prepared on standing water by using bamboo mating of floating banana rapt. The platform is fixed with poles and 2-3 cm thick layer of mud is placed over the platform.

The length of seed bed is 3m and width is 1m. A drain of 10-12 inch is helpful for intercultural operations.

Seed Rate:

For direct seeding 80-100 kg/ha

For transplanting 35-40 kg/ha

Seedlings in one square meter can cover an area with 25-30 square meters.

Sowing in the Seed Bed:

Dry seedbed: Dry seeds are sown. 100-150 gm seeds/m² are used.

Wet Seedbed: Sprouted seeds are sown in the seedbed.

Dapog Seedbed: Pre germinated seeds are sown over the well arranged banana leaves, concrete floor or plastic sheets. Usually 3-4 kg seeds/m² is used.

Floating Seedbed: Pre germinated seeds are used as wet seedbed.

Care for Nursery Bed:

After sowing the seeds in the nursery bed care should be taken to raise healthy, strong and vigor seedlings. In case of wet nursery bed water should be kept in all time. Irrigation, drainage and weeding is given when need. If required fertilizer is supplied at following doses:

For 500m² seedbed

Manure/Fertilizer	Dose
Cow dung	1-1.5 tons
Urea	3-4 kg
TSP	3-4 kg
MP	1.5 kg