Effects of NaCl salinity on miniature dwarf tomato ‘Micro‐Tom’: I. Growth analyses and nutrient composition¹

Supported in part by Illinois Agricultural Experiment Station (Projects 65–353 and 65–363); The Horticulture Research Institute; University of Illinois College of Agriculture Office of Resident Instruction; and the Fred Gloeckner Foundation. Dr. J. Scott's (University of Florida Institute of Food and Agricutural Science, Gainesville) generous donation of ‘Micro‐Tom’ seeds and Dr. W.L. George's (University of Illinois College of Agriculture) helpful suggestions regarding experimental design and culture are greatly appreciated.

Abstract

The growth and nutrient composition of miniature dwarf tomato selection Lycopersicon esculentum ’Micro‐Tom’ plants grown from seedling to harvest in solution batch culture at four different NaCl salinity levels (2.4 [control, no NaCl], 7.6, 12.8, or 18 dS‐m^‐1 solution conductivities) was studied. Specific leaf area and relative growth rate generally decreased with increased NaCl. Shoot‐root, root mass, and leaf area ratios initially increased but later resumed control values. Although reduction in leaf area in response to higher NaCl was noted at 4 weeks, leaf and root dry mass was not significantly reduced until 12 weeks. At 12 weeks, enhanced carbohydrate partitioning toward shoot vegetative growth was observed in the highest NaCl level as reduced harvest index and increased leaf and stem mass ratios. An immediate proportional increase in leaf Na and decrease in Ca occurred with solution NaCl concentration. Although leaf K declined significantly between 4 and 8 weeks, there were no differences between treatments. Cu and Zn content escalated with increasing NaCl, with Zn increasing three fold between the lowest and highest NaCl levels.

Notes

Supported in part by Illinois Agricultural Experiment Station (Projects 65–353 and 65–363); The Horticulture Research Institute; University of Illinois College of Agriculture Office of Resident Instruction; and the Fred Gloeckner Foundation. Dr. J. Scott's (University of Florida Institute of Food and Agricutural Science, Gainesville) generous donation of ‘Micro‐Tom’ seeds and Dr. W.L. George's (University of Illinois College of Agriculture) helpful suggestions regarding experimental design and culture are greatly appreciated.

Assistant Professor, Graduate Assistant, Associate Professor, and Professor (corresponding author) Department of Horticulture, University of Illinois.