Irrigation in vining peas: how much water?

The amount of water you use is just as important as the timing when managing the irrigation of vining pea crops. The best increases in yield come when you allow well-timed moisture stress at key points in the crop’s development.

This information was last updated in 2012.

Key points

• Some moisture stress at specific times in the growing season can support higher yields. 
• Too much water at the wrong time can suppress yields.  

How much water do vining peas need? 

Studies suggest that during vegetative growth and when flowering begins, the optimum irrigation is 25mm of water. At the pod fill stage, you should not irrigate to more than 30mm. 

Note that the best increases in yield are seen when the crop is under moisture stress at certain points of development as described in the timing of irrigation page.  

The impact of too much water 

Of course, when weather conditions have delivered adequate moisture for your crop, there will be little advantage in irrigating – and it is also important to realise that too much water can suppress yields.  

If roots are bathed in water for a prolonged period, plants will stop functioning properly and crop development will suffer. In extreme waterlogged conditions, plants will die.   

If roots are waterlogged for 24 hours, the pea plant stomata will close and transpiration will stop; if this continues for a further 24 hours, then leaves begin to desiccate and roots begin to break down. 

This damage is irreversible and plants will exhibit typical foot rot symptoms which reduces yield significantly. 

Original author

James Scrimshaw, PGRO