Salinity and Nitrogen Level Affects Germination, Emergence, and Seedling Growth of Tomato

Abstract

ABSTRACT High salt concentrations in soil restricts establishment of direct-seeded tomato Lycopersicon esculentum Mill. Effects of four irrigation water salinity levels (0.5, 2.5, 5, and 10 ds·m−1) and four nitrogen fertilizer rates (0, 5, 10, and 15 mM) on germination, emergence, and seedling growth of tomato cvs. Pascal, Red Stone, Shohba, Super Marmand, and Tanshet Star were investigated in a greenhouse. Germination percentage, germination rate, emergence percentage, and emergence rate were decreased and delayed with increasing salinity, from 2.5 ds·m−1 to 10 ds·m−1, in all cultivars. All seedling growth characters, except seedling height, were decreased with increasing salinity levels and enhanced with increased N levels. At the germination and emergence stages, cvs. Pascal and Tanshet Star were more tolerant to salinity level than cvs. Shohba, Super Marmand, and Red Stone. The interaction between salinity and N levels was significant for seedling leaf numbers and fresh and dry weight, indicating that N fertilization may reduce negative effects of salinity. However, the results of other characters did not describe any clear trend to indicate that N levels had a direct effect on salinity induced decreased growth.