Suaeda salsa, a desalinating companion plant for greenhouse tomato

Abstract

To determine its effect on salinity of the growth medium and on tomato (Lycopersicon esculentum Mill.) growth and yield, the halophyte Suaeda salsa (L.) Pallas, or seepweed, was planted as a companion plant in the closed insulated pallet system (CIPS). In this production system, water moves from a bottom reservoir through capillary wicks to the medium in the root pouch in response to plant uptake. Fertilizers are placed at the top surface of the root matrix, so nutrient ions move downward to the roots by chemical ion diffusion to establish relatively stable chemical gradients within the matrix. Plants were subjected to capillary subirrigation water containing 0 or 4 g · L-1 NaCl. Sodium (Na+) concentration of the root medium at termination was 50% lower when S. salsa was grown in the same pouch with tomato. Sodium concentration was also significantly less in the tomato foliage, but S. salsa did not prevent suppression of growth of tomato plants by NaCl. Suaeda salsa plants reduced blossom end rot of tomato fruit but did not significantly affect fruit weight, number or yield.