2013 Annual Report
We completed a greenhouse alfalfa experiment using 15 genotypes, salinity levels and two different water qualities. We evaluated plants grown under water compositions typical of interior continental inland valleys (such as the Central Valley of California), as well as waters more representative of coastal saline regions. We did not see differences in yield related to these two different water types, thereby indicating that this factor is not critical to representing alfalfa tolerance to salinity. We found significant differences in alfalfa genotype response to salinity and have selected several genotypes for further salt tolerance evaluation.
We established, in a greenhouse study, that grafted tomato plants had greater yield under both non-saline control conditions as well as under saline conditions. We examined the impact of water composition as well as salinity on marketable fruit yield (mass) fruit size, number of fruit and shoot and fruit ion composition. Our data indicate that for tomato, decreased yield under saline conditions is well related to increased leaf sodium concentrations. However, grafted plants had reduced leaf sodium contents relative to non-grafted plants at all salinity levels. Increased solution chloride was not related to changes in yield, suggesting that yield reduction from chloride ion toxicity is not a consideration for tomato. Additionally, grafted plants had increased yield but slightly higher leaf chloride concentrations as compared to non-grafted plants, again indicating that chloride ion concentration was not a factor in yield loss under saline conditions. Grafting is recommended as an option to increase tomato yield regardless of irrigation water salinity.