Orchardists need to justify their water use.  Irrigation of farmland accounts for approximately 70% of water use in the valley.  Projected climate change indicates a longer growing season, higher water demand, and less available water in the future. Competition with residential, recreational, industrial and environmental users for water resources in the valley means users must quantify their water use and demonstrate responsible management. Responsible irrigation practices also reduce the risk of water contamination and improve relationships with water providers and other users.  Combined with an increase in orchard productivity, irrigation management is beneficial to all water users.  This section explains how water management affects tree fruit production and how to use it to improve orchard productivity.

How does irrigation affect the orchard?

Proper watering practices are essential for the support and nourishment of the root system.  The consequences of improper watering can include:

Overwatering

• Physical damage to soil structures

• Decreased infiltration capacity

• Root death

• Increased susceptibility to soil pathogens (eg. crown rot)

• Soil acidification

• Nutrient & cation losses

• Poor fruit quality

Underwatering 

• Decreased nutrient uptake

• Heat stress & sunburn

• Premature fruit & leaf drop

• Early maturity

• Reduced return bloom & set

• Poor fruit quality Lower yield

What are the economic implications for the grower? 

Costs related to inefficient irrigation include:

• Time, labor and energy spent maintaining and operating inefficient systems

• Revenue losses due to poor quality fruit and trees

• Wasted nutrient/fertilizer inputs

• Fines for exceeding water allotments