Read the statements with respect to water management in maize
A. Most critical stage for irrigation is flowering period including tasseling, silking and pollination
B. Water deficit at flowering stage causes heaviest yield loss mainly due to reduction in grain size
C. Under the conditions of adequate irrigation water, irrigations should be applied at 25 % depletion of available soil moisture
D. Under the conditions of adequate irrigation water, irrigations should be applied at IW/CPE of 0.6 or 0.8 throughout growth period of crop
E. As maize is mostly grown in rainy season, applying irrigation is wasteful
Choose the correct answer from the options given below:
Show Hint
For maize, the flowering stage (tasseling and silking) is the most critical window for water. Any water stress during this short period can cause irreversible yield loss, making supplemental irrigation essential even in the rainy season.
Step 1: Understanding the Concept:
Maize is highly sensitive to both waterlogging and water deficit.
Proper scheduling of irrigation based on critical growth stages and crop water indicators is essential for maximizing yield and water-use efficiency. Step 2: Detailed Explanation:
Let us evaluate each of the statements:
- Statement A: "Most critical stage for irrigation is flowering period including tasseling, silking and pollination."
This is correct.
Water stress during these stages disrupts pollen viability and silking synchronization, leading to poor fertilization and barrenness.
- Statement B: "Water deficit at flowering stage causes heaviest yield loss mainly due to reduction in grain size."
This is correct.
Severe water deficit during flowering reduces the number of fertilized grains and limits dry matter accumulation, resulting in smaller grain size and significant yield loss.
- Statement C: "Under the conditions of adequate irrigation water, irrigations should be applied at 25% depletion of available soil moisture."
This is incorrect.
Maize can tolerate up to 50% depletion of available soil moisture without significant yield loss. Irrigation at 25% depletion is too frequent and leads to excessive water use.
- Statement D: "Under the conditions of adequate irrigation water, irrigations should be applied at IW/CPE of 0.6 or 0.8 throughout growth period of crop."
This is correct.
Scheduling irrigation at an Irrigation Water to Cumulative Pan Evaporation (IW/CPE) ratio of 0.6 during vegetative stages and 0.8 during critical reproductive stages is a standard, efficient practice for maize.
- Statement E: "As maize is mostly grown in rainy season, applying irrigation is wasteful."
This is incorrect.
Rainfall is often erratic, and dry spells can occur during critical growth stages. Supplemental or life-saving irrigation during these dry spells is crucial for preventing crop failure.
Therefore, statements A, B, and D are correct. Step 3: Final Answer:
The correct option is (D).
