Rice is the principal food crop of Assam and NE India. More than 90% population of the region depends on rice for their caloric requirement. Rice has been playing a key role in all spheres of life in the region. Realizing the importance of the crop in the state, rice research was initiated through establishment of a Rice Experimental Station at Karimganj in 1913. Ten years later, i.e. in 1923, another rice experimental station came up at Titabar in the Brahmaputra Valley of the state which is situated at 20 km away from Jorhat, on Titabar- Borholla road. The station was recognized as a funded centre of All India Coordinated Research Project on Rice (AICRP on Rice) in the year 1965 and it was brought under the administrative control of Assam Agricultural University, Jorhat in 1969. Considering the immense contribution of the station in the field of agricultural research and development, especially in rice, it has been upgraded to an institute and renamed as AAU-Assam Rice Research Institute, Titabar on 27th January, 2023.
The mandate of the station is to generate technological packages through interdisciplinary research and disseminating production technologies to the farmer\'s field to increase rice productivity and sustainability by adopting applied, basic and location specific, need based research on rice, to conserve the genetic resources of rice besides producing quality seeds of popular high yielding varieties. Besides the mandated activities of the institute, every year nearly 60-70 AICRP on Rice trials are conducted under six disciplines, viz., Plant Breeding, Crop Physiology, Entomology, Plant Pathology, Agronomy and Soil Science.
AAU-Assam Rice Research Institute (AAU-ARRI), Titabar has so far developed more than 48 rice varieties through its breeding program. At present, the institute is maintaining around 7000 accessions of different categories out of which around 3000 are indigenous rice cultivars. Many of these cultivars are now being utilized in the breeding programs within and outside the state.
Out of the total sanctioned posts of seven Scientists, four Field Assistants, one Stenographer, one Driver and one Tractor Operator under AICRP on Rice, all the posts are filled up except the lone posts of Stenographer and Tractor Operator.
Recently
in 2022, AAU-ARRI, Titabar has developed and popularized an unique high yielding purple
rice variety namely Labanya. This
newly developed variety is a
lodging friendly high yielder with a yield level of 4.5-5.0 t/ha and a duration
of 145-150 days. It is aromatic with a lower Glycemic Index (GI) and an
intermediate amylose content of around 18%. Labanya is easy to cook is having
higher antioxidants and flavonoids, phenolic compounds, essential amino acids,
minerals, protein, fiber content compared to normal rice. Labanya was launched
as a product for sale in December 2021 and since then it has been made
available online on e-commerce platforms such as Amazon as well as in offline
marketplaces. Several value added products like bread, cookies, kheer, pulao,
beer, ready-to-eat roasted powders and so on are being made from Labanya which
is gaining a huge popularity in the locality.
A high yielding medium slender grain rice variety with high milling
recovery and good cooking
quality.
Suitable for flood-prone double cropped areas.
The variety can withstand
12 days of complete submergence
Maturity duration: 135-140 days.
Yield: 4.5-5.0
t/ha
Year of Notification: 2022
During
2017, two new submergence tolerant varieties viz., Ranjit Sub-1 and Bahadur
Sub-1 have been developed with the help of Marker Aided Selection and
released for the state. Ranjit Sub-1
and Bahadur Sub-1 can tolerate
submergence up to 12 days. The grain types of these two varieties are similar
to their respective recurrent parents, Ranjit
and Bahadur. These are the first
two varieties from entire North East India developed with the help of
biotechnological interventions.
· Derived from the
cross Ranjit/ Swarna Sub1//
Ranjit
· Year of release/ recommendation: 2018
·
Suitable for flood-prone areas, can withstand
two weeks of submergence at vegetative stage
· Matures in 145-150 days
· Yields 5.5-6.0
t/ha
· Non lodging
· Medium slender
grains with high milling
recovery
· Good cooking
quality
Bahadur Sub1
· Derived from the
cross Bahadur/ Swarna Sub1//
Bahadur
· Year of release/ recommendation: 2018
· Suitable for flood-prone areas, can withstand two weeks of submergence at vegetative stage
· Matures in 140-145 days
· Yields 5.5-6.0 t/ha
· Medium bold
grains with high milling recovery
· Good cooking
quality
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Status Paper on Rice in
Assam
AAU-Assam Rice Research Institute, Titabar-785630
Assam, India
1Chief
Scientist (Retd.), AAU-ARRI, Titabar
2Director
of Research (Agri.), AAU, Jorhat
3Principal
Scientist (Retd.), AAU-ARRI, Titabar
4Sr.
Scientist (Rice Breeder), AAU-ARRI, Titabar
5Scientist
(Entomology), AAU-ARRI, Titabar
6Professor,
Dept. of Crop Physiology, AAU, Jorhat
I.
INTRODUCTION
Assam
is one of the seven states of northeast India, which is located between 240
N and 28018/ N latitudes and 890.4/E and 9600/ E longitudes. The State is surrounded by Arunachal Pradersh, Nagaland, Manipur and Myanmar in
the East Mizoram, Tripura and Meghalaya in the
South Bangladesh and West
Bengal in the West and Bhutan and Arunachal Pradesh in the North. The state is surrounded by many hills in
all directions. The total geographic area of Assam is 78438 sq. km with a population of 3.12 crores as per census
2011.
The two main rivers viz., the Brahmaputra and the Barak flow through the state with 40 and 7 major tributaries each, respectively.
The Brahmaputra valley occupies about 5.6 million ha with 24 administrative districts while the Barak valley is about 0.7 million
ha with 3 districts. The Brahmaputra
flows from the east (Sadiya) to west (Dhubri). The altitude at Sadiya is 134 m
while in Dhubri it is 35 m. The
Brahmaputra valley is an alluvial plain having varying topography. The Barak River flows from east to west through undulating plains.
There are two hill districts viz. Karbi Anglong and North Cachar Hills in the state occupying about 1.5 million ha. The hills constitute a part
of the Barail and the Meghalaya ranges with maximum altitude of about 1000 m
above mean sea level. Thus, the state has three distinct
physiographic units - the plains,
the plateaus and the hills.
The
state has its climatic and physiographic features favourable for rice
cultivation and the crop is grown in
a wide range of agro-ecological situations. It is grown from hill slopes of
Karbi-Anglong to very deep-water areas of North Lakhimpur and Dhemaji during
very wet humid months to drier period
of the year. Wide variation of
physiographic features and climatic characteristics have resulted three
distinct growing seasons
of rice viz., ahu (Feb /March
- June /July), sali (June
/July - Nov /December) and boro (Nov /December
-May /June). To match with diverse land situations
encountered with varying growing season, diverse varieties are traditionally
grown in the state since unknown
past. Ahu or autumn rice is grown
during February/March to June/July.
As
per the final estimates, the total area under paddy cultivation during the year
2022-23 was 22.58 lakhs hectares. The area under autumn rice is 0.79 lakhs
hectares (3.5 percent of total rice area), winter rice is 18.51 lakh hectares
(79.78 percent of total rice area), and summer rice is 3.78 lakh hectares (16.72
percent of total rice area) during the year 2022-23 (provisional). Total area
under paddy shows a steady decline mainly due to decline in area under autumn
rice (ahu rice). Area under Winter Rice and Summer Rice marginally declines.
The total rice area decreases 1.92% in the year 2022-23 over the previous year
2021-22. Total production of rice in the state during 2022-23 is 59.15 lakh
tons and the contribution of autumn rice, winter rice and summer rice is 2.02%,
79.05% and 18.92%, respectively during the year 2022-23. Details of the
different classes of rice in Assam are presented in Table 1.
Table 1. Agricultural classes
of indigenous rice in
Assam
Seasonal class* | Growing season | Duration | Remarks |
Ahu (Autumn rice) | March/April | 80-130 | Photoperiod insensitive, early maturing usually |
Dumai |
| 80-90 | Generally |
Murali |
| 90-100 | -do- |
Chengri |
| 90-100 | -do- |
Ahu (transplanted) |
| >100 | Grown transplanted |
Sali (Winter rice) | June/July to Nov./Dec | 150-180 | Photoperiod |
Sali |
| 150-180 | Coarse grained |
Lahi |
| 150-180 | Medium grained |
Joha |
| 150-180 | Scented, fine grained |
Boro |
| 150-180 | Glutinous or sticky rice, |
Chakuwa |
| 150-180 | Soft rice with |
Asra | April/May to Dec./Jan | 240-270 | Medium deep-water rice, grown broadcast or transplanted in the low-lying areas, |
Bao | April/May to Dec/Jan | 270-300 | Deep water or |
C. Boro (Summer rice) | Nov.-May/June | 180-200 | Photoperiod |
D. Hill Rice (Jhum) | Mar/April | 210-250 | Photoperiod insensitive. Grown in hills slope |
*Based on the time of harvest.
II.
ZONAL INFORMATION
a.
Climate
By and large the climate of Assam is
subtropical with warm humid summer and cool
dry winter. Due to its large variation of physiography, the state has a very
wide variation of climatic conditions. Climate of North East (NE)
India, including Assam is distinct from that of the rest of India due to special features like topography,
alternating pressure cells over NE India and Bay of Bengal, predominant maritime tropical air mass,
the roving periodic Western disturbances and the Local Mountain and valley winds. The climate of the Brahmaputra and
Barak valley are characterized by hot and wet summer
and mild to moderately
cold dry winter.
India
enjoys a typical monsoonal climate and Assam is no exception. Four distinct
seasons viz., Pre-monsoon
(March-May), Monsoon (June-September), Post-monsoon (Oct-Nov) and winter (Dec-Feb) are quite obvious in the State.
Pre-monsoon is not very hot in the State. Rainfall starts generally from the 3rd week of
March and the weather becomes pleasant. During winter and pre-monsoon seasons, western disturbances bring precipitation in the region.
The
State gets more than 60% of the annual precipitation during monsoon season,
which starts in the 1st
week of June. Because of the movement of the trough line towards north of India (around Himachal) or due to weak
depressions in Bay of Bengal,
sometimes the monsoons get weaker
after it starts blowing. This leads to a dry spell of 7-15 day duration during
the season. It is called “monsoon
break” and is deleterious to the crops, particularly to the standing paddy
crop. The season is characterized by
flood, inundation and water logging. Along the Brahmaputra and Barak valley, the ground water level comes
to the surface. The monsoon season
receives maximum amount of rainfall
(62-65% of annual rainfall) followed by pre-monsoon (20-23%), post-monsoon (6- 8%) and winter
(2-3%) season.
b.
Soil type
Soil of Assam are described to be originated from residual or transported materials. The residual material is
derived from the rocks of Archeans age which consists mainly of gneiss, schists and granites. The
transported type consists of material brought from flowing rivers from Himalaya and Assam. pH
ranges from acidic to heavily acidic in most of the areas. The low pH status
is due to the leaching of bases under the
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