Tomato Plant Response to Soil Salinity1
- I. Papadopoulos and
- V. V. Rendig2
Tomato (Lycopersicon esculentum var. VF 145) plants were grown in a greenhouse to determine the effects of salinity on growth and yield. The plants were grown in soil (Typic Xerofluvents, coarse-loamy, mixed, nonacid, thermic) using regular or four-compartment containers allowing splitting of the root systems. Nutrient solutions made saline with NaCI and CaCl2 to electrical conductivities (EC) of 1, 2, 3, 4, and 5 dS/m (dS/M = mmho/cm, referenced at 25°C) were applied twice a day in the undivided root systems. In the split-root series, each of the four compartments was irrigated with solutions of different EC, while the regular containers were irrigated with a nutrient solution satinized to a level equivalent to the mean value of the solutions used for irrigating the four-compartment units. The nutrient solutions were recycled through the containers, so that responses of plants subjected to increasing salinity up to 35 dS/m could be evaluated. With increasing salinity fruit fresh weights decreased markedly, with lesser decreases in shoot weights in both systems. Plants with their root systems divided and growing in containers with differentially salinized soil were less severely affected. Yield and growth correlated better with the initial electrical conductivity (ECin) of the nutrient solutions applied than with the EC values of the solutions extracted from the soil. Roots were less sensitive to root-zone salinity than were tops. In the split-root system, any reduction in the root growth in the compartments with high salinity levels was compensated for by more growth of those portions of the root system in the less saline environment. During the latter part of the growing period, levels of soil solution salinity were generally greater in the soils in which plants were grown in the undivided root systems than in soils in the split-root systems.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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