P. K. Sarkar
Chief Scientific Officer
IWM Division, BARI, Gazipur-1701
A. Khatun
Principal Scientific Officer
IWM Division, BARI, Gazipur-1701
S. K. Biswas
Senior Scientific Officer
IWM Division, BARI, Gazipur-1701
The study was undertaken to study the water productivity of maize (BARI Hybrid Maize- 5) under deficit irrigation practices and to predict crop growth stages during which the crop can withstand water stress with limited effect on yield. The results showed that variation in timing and amount of irrigation had a reasonable impact on grain yield. The stem-elongation stage (30-35 days after sowing) was not found very sensitive to water stress. Water stress at maturity stage also had a limited effect on yield. Imposing water deficit at the heading stage (60-70 days after sowing, treatment T3) resulted to the highest yield reduction. Water productivity was observed the lowest (1.88 kg/m3) for the same treatment and the highest (2.62 kg/m3) for the treatment T4 (stress at the grain filling stage). The highest yield (8.003 t/ha) was obtained from the treatment T1 which was fully irrigated (four irrigation at four growth stages). On the other hand, a slightly low yield (7.930 t/ha) was obtained from the treatment T2 (three irrigation at three stages except stem elongation). This result implies that omitting irrigation or a slight stress at the stem elongation stage is not very harmful in respect of grain yield.
Deficit irrigation, Irrigation, Maize
Crop-Soil-Water Management
The main objective of the study was to investigate the impact of deficit irrigation on maize yield and to identify the sensitive growth stages to soil water stress.
The experiment was conducted at the experimental field of IWM Division, BARI, Gazipur during 2012-2013. BARI Hybrid Maize 5 was used as the test crop. The treatments were selected based on applying irrigation at different growth stages as below:
T1 = Full irrigation (at 15-20 days after sowing (DAS), 30-35 DAS, 60-70 DAS and 85-95 DAS)
T2 = No irrigation at stem elongation stage (30-35 DAS)
T3 = No irrigation at heading stage (60-70 DAS)
T4 = No irrigation at grain filling stage (85-95 DAS).
The crop was planted on 20 December 2012. The crop was harvested on 13 May 2013. The soil of the experimental field was silty clay loam. The field capacity was 32%. The bulk densities were 1.51 gm/cc. There were 4 irrigation levels in the experiment. Irrigations were applied as per treatments.
Annual Report, IWM Division, BARI, Gazipur
Based on the results obtained from the last year's study, the conclusion is that water stress at the heading stage (60-70 DAS) is most harmful in respect of grain yield. Water stress at the stem elongation stage (30-35 DAS) is not very harmful and irrigation may be omitted at that stage. So farmers are suggested to ensure irrigation at the heading stage (60-70 DAS) to avoid decrease of grain yield.