By N.K. Saha, M.K. Mondal, E. Humphreys, M.H. Rashid, P.C. Paul, S.P. Ritu

1. Welcome

2. Triple rice in a year:
Is it feasible for low salinity areas of the
coastal zone of Bangladesh?
N. K. Saha, M. K. Mondal, E. Humphreys, M. H. Rashid,
P. C. Paul, S. P. Ritu

3. Rationale
● Fresh water all the year round in much of Barisal
● Current cropping patterns:
○ Fallow/Aus-T.Aman-Fallow/Keshari
○ 0-3 2-3.5 0-1 t/ha
● Possible technology to fit 3 rice crops in a year
● 50% cultivable land medium high (SRDI 2010)
● HYV rice
● River water for Boro, river water & rainfall for Aus
drainage to Aman crop.

4. Hypotheses of the study
M J J A S O N D J F M A M
T. Aman (130-140 d) Boro (140-145 d)
Aus (100-105 d)
● 3 high yielding rice crops per year IS possible in
coastal zone where
○ fresh water available throughout the year
○ ability to drain excess water

5. Objectives
To evaluate combination of planting dates and aman varieties
for triple rice system
● Feasibility
● System yield
● Irrigation water requirement for boro

6. Basic site information
● PSTU farm, Patuakhali
● Clay loam
● Lowland
Drain & Water source ~100 m

7. Experimental design
Treatments:
➢ E1-3: aus sowing dates/establishment method
➢ V1-4: aman varieties
➢ D1-5:boro sowing dates

8. Aus establishment treatments (E)
● E1= Sown 10 April, transplanted 1 May
● E2= Sown on 25 April, transplanted 15 May
● E3= Sown Direct (wet) seeded 1 May
Variety: OM1490 (100 days)

9. Aman variety treatments (V)
RULE:
Transplanting date 10 d after harvest of each aus treatment
E1 and E2:
● V1 BRRI dhan49 (duration 135 d)
● V2 BRRI dhan52 (duration 145 d, submergent tolerant)
E3:
● V3 BRRI dhan33 (duration 118 d)
● V4 BRRI dhan53 (duration 125 d)

10. Boro sowing date treatments (D)
RULES:
● First transplanting date NOT less than 10 d after aman
harvest, & NOT before 15 November
● Second transplanting date 15 d after first
● D1= 15 November
● D2= 20 November
● D3= 30 November
● D4= 05 December
● D5= 15 December

11. Treatment Combinations
Aus Aman Boro CS
E1 =1 May V1= BRRI dhan49 D1= 15 November 1
D2 = 30 November 2
V2 =BRRI dhan52 D1= 15 November 3
D2 = 30 November 4
E2=15 May V1 =BRRI dhan49 D1= 30 November 5
D2= 15 December 6
V2 =BRRI dhan52 D1=30 November 7
D2=15 December 8
E3=1 May V1 =BRRI dhan33 D1= 20 November 9
D2= 05 December 10
V2= BRRI dhan53 D1=20 November 11
D2= o5 December 12

12. Crop management information
● Crop establishment:
Transplanting (all crops): 21 day-old seedlings
20 cm x 20 cm
Direct seeded aus (Dsaus): 20 cm row spacing

13. ● Fertilizers:
Season N
(kg/ha)
P2O5
(kg/ha)
K2O
(kg/ha)
CaSO4
(kg/ha)
ZnSO4
(kg/ha)
Aus 100 60 40 60 10
Aman 100 60 40 60 10
Boro 120 60 40 60 10
DS.aus 10-15 DAE, 30-35 DAE, 45-50 DAE(5-7DBPI) and 60-65 DAE
T.Aus
T.Aman Final land preparation, 25 DAT, 5-7 DBPI and at heading
Boro
BRRI, 2012

14. Irrigation:
● T.Aus and DSaus – irrigated as needed from canal
● Boro– Fully irrigated from canal (pumping)
Drainage:
Excess water during aus & aman– at low tide

15. Weed, pest and disease management
• Good control of pests and diseases (BRRI, 2012 recs)
(except brown spot in aman 2013 and boro 2012-13 first 2
sowings)
• plastic barrier to keep rats out
• netting to keep birds out
Bird nets
Plastic barrier

16. Crop Monitoring
● Phenology dates:
● PI, FL, PM
● Biomass: fortnightly
● Yield and yield components:
● Panicles/m2
● Florets/panicle
● Floret fertility
● 1000 grain wt.
● Grain & straw yield

17. Irrigation monitoring
● The amount of water/plot:
○ pump discharge rate (R), duration of irrigation (T), and plot
area (A).
○ Formula: (R X T)/A

18. T. Aman 2012

19. Field duration of aman crop

20. Field water depth during aman 2012

21. Effect of sowing date and variety on grain yield of
aman

22. Field duration of aus crop

23. Effect of sowing date on aus yield

24. Aus crop

25. Effect of sowing date on boro duration

26. Daily mean temperature during boro 2012-13 and
2013-14

27. Effect of sowing date on yield of boro

28. Boro crop

29. Total system grain yield

30. Duration of the cropping pattern in the field during
2012-13 and 2013-14

31. Conclusion & Recommendation
● It is feasible to fit 3 rice crop in a year
● 13.4 to 17.2 t/ha/yr about 3 x farmers’ harvest
● Average 10-12 day turn around period
● Need for model simulation to evaluate performance
over range of weather conditions
● Will pests & diseases become a problem in triple rice
systems – need for ecologically friendly management
systems

32. Thank you

33. Irrigation water requirement during
boro 2012-13 to 2013-14

34. Irrigation water productivity(kg/ha-mm) of BRRI
dhan28 during boro 2012-13 to 2013-14