Field Crops> Wheat (Triticum aestivum L.)> Water Management

Adequate soil moisture is required for normal development of the wheat plant at all the stages of growth. The crown root initiation stage and heading stage are critical stages when plant suffers most due to moisture stress.

The following schedule of irrigation should be followed for dwarf varieties of wheat:

In case of dwarf high yielding varieties, a pre-sowing irrigation should be given and crop sown when the field becomes fit for operation.

First Irrigation: The first irrigation to the standing crop should be given 20-25 days after sowing, i.e., at the crown root initiation stage. In cooler regions like hilly tracts and in late sown wheat, it is desirable to apply first irrigation approximately 25 to 30 days after sowing. Delay in giving this irrigation should be avoided as it would result in upsetting the synchronous tillering in these varieties, subnormal heads, poor root system and finally poor grain yield. It is the most critical stage for irrigation.

Second Irrigation: At tillering stage, within 40-45 days after sowing.

Third Irrigation: At late jointing stage, within 70-75 days after sowing.

Fourth Irrigation: At flowering stage, within 90-95 days after sowing. Irrigation at this stage is also important because during this period plants suffer most from soil moisture deficiency. The grain number and grain size are reduced considerable.

Fifth Irrigation: At dough stage, within 110-115 days after sowing.

The total number of irrigations required will vary depending upon soil type, winter rainfall, amount of water applied per irrigation.

Under limited supply of water the following schedule of irrigation should be adopted for best utilization of available quantity of water.

Where only one irrigation is possible, give it at crown root initiation CRI stage, i.e., 20-25 days after sowing.

Where two irrigation are available, first irrigation should be given at CRI stage and second at flowering stage.

Where three irrigations are possible, first irrigation should be given at CRI stage, second at late jointing (boot) stage and third at milk stage.

These recommendations strongly stress the importance of irrigation at CRI stage. It has been sound that each week delay in first irrigation from CRI stage results in yield reduction of 2-3 quintals per hectare.