IMPROVING YIELD OF VEGETABLES GROWN WITH OVER-CANOPY, SALINE IRRIGATION

Saline irrigation decreases vegetable yields.
Losses under sprinkler irrigation can be greater than those with drip irrigation.
The extra loss has been attributed to foliar uptake of salts.
In 3 experiments, we investigated the effect of a short non-saline irrigation applied immediately following each saline irrigation on yields of glasshouse grown onion and potato crops.
Experiments consisted of various combinations of irrigation treatments:

• control – sprinkled with non-saline water for the whole irrigation event, (CONT)
  
• saline – sprinkled with saline water for the whole irrigation event, (SALT)
  
• saline plus flush – sprinkled with SALT water for 92.5 or 85 or 77.5% of the irrigation event and CONT water for the remainder of the irrigation event, (SALT+7.5% or 15% or 22.5%F)
  
• 85% saline – sprinkled with saline water containing 85% of the NaCl added to SALT treatment, (85%SALT)

In the first potato experiment, SALT+15%F with irrigation water salinity (ECi) of 4.3 dS/m had 30% higher yield than the SALT treatment with ECi 4.8 dS/m.
In the second potato experiment, SALT+15%F, ECi 3.8 dS/m, had 60% higher yield than the 85%SALT, ECi 3.8 dS/m.
In the onion experiment, the SALT+15%F, ECi 3.4 dS/m, yield was equivalent to that in the 85%SALT, ECi 3.4 dS/m.
We conclude that these results show that foliar salt uptake is causing yield loss in potatoes, but not in onions.
In potatoes under sprinkler irrigation with saline water, applying a short non-saline flush at the end of each irrigation increases yield.

V International Symposium on Irrigation of Horticultural Crops

R.M. Stevens, J.M. Pech, G.J. Grigson

potatoes, onions, soil salinity, non-saline flushing, sprinkler, foliar uptake

https://doi.org/10.17660/ActaHortic.2008.792.76