Skip to main content
ARS Home » Research » Publications at this Location » Publication #300838

Title: Tomato salt tolerance: Impact of grafting and water composition on yield and ion relations

Author
item SEMIZ, GULUZAR - Ankara University Of Turkey
item Suarez, Donald

Submitted to: Turkish Journal of Agriculture and Forestry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/22/2015
Publication Date: 6/8/2015
Citation: Semiz, G.D., Suarez, D.L. 2015. Tomato salt tolerance: Impact of grafting and water composition on yield and ion relations. Turkish Journal of Agriculture and Forestry. doi: 10.3906/tar-1412-106.

Interpretive Summary: The major quantity of tomato production in the world is via irrigation in arid and semiarid regions of the world. These regions face critical shortages of fresh water, hence there is a need to evaluate and develop crop production systems with recycled wastewater and brackish groundwater. Grafting tomato and other vegetables on different rootstocks is increasingly popular, especially for greenhouse production as it has proven to increase yields. We evaluated the salt tolerance of tomato cv Big Dena under both ungrafted conditions and when grafted on Maxifort rootstock, under a series of 5 salinity levels and two water composition types. We salinized the irrigation water with either a sodium-calcium-chloride composition typical of coastal Mediterranean ground waters as well as a mixed sodium –calcium-sulfate-chloride type water composition, more typical of interior basin ground waters such as those of the Central Valley CA. There were no statistically significant differences in the salt tolerance relative to the water type, indicating that the chloride ion is not an important factor in tomato yield reduction associated with salinity. Grafted tomato plants exhibited increased yield both under control and elevated salinity levels relative to non-grafted plants. In contrast to absolute yield relationships, expression of salt tolerance in terms of relative yield, provides the misleading conclusion that non-grafted plants are more salt tolerant than grafted plants. Our data also indicate that for tomato, decreased yield under saline conditions is well related to increased leaf sodium concentrations. This information is of use to irrigation specialists, plant breeders and vegetable producers utilizing or evaluating use of saline or recycled waters for irrigation.

Technical Abstract: We evaluated the salt tolerance of tomato cv Big Dena under both non-grafted 2 conditions and when grafted on Maxifort rootstock, under a series of 5 salinity levels and two irrigation water composition types. The salinity levels of the irrigation water were -0.03, -0.15, -0.30, -0.45, and -0.60 MPa osmotic pressure (corresponding to specific electrical conductivity values of 1.2, 4.0, 8.5, 12, and 15.8 dS/m, respectively). We salinized the irrigation water with either a mixture of salts with a predominant composition consisting of Na+-Ca2+-Cl- salts, a composition typical of coastal Mediterranean ground waters or alternatively, a salt composition that was of mixed Na+-Ca2+-SO42—Cl- ions, a water composition more typical of interior continental basin ground waters such as those of the Central Valley California, U.S.A. We determined that there were no statistically significant differences in the tomato salt tolerance (fruit yield) relative to the water type. This result indicates that in the range of Cl- concentrations tested in our experiment (up to 150 mmol L-1), Cl- is not an important factor in tomato yield reduction associated with salinity. Grafted Big Dena on Maxifort tomato plants exhibited increased yield both under control and elevated salinity levels relative to non-grafted Big Dena plants. In contrast to absolute yield relationships, expression of salt tolerance in terms of relative yield, as salt tolerance is commonly expressed, provides the conclusion that grafted Big Dena on Maxifort tomato plants are slightly less salt tolerant than non-grafted Big Dena plants. Our data also indicate that for tomato, decreased yield under saline conditions is well related to increased leaf Na+ concentrations.