POTENTIAL USE OF SPENT TEA LEAVES (Camellia sinensis L.) IN PRIMING TREATMENT TO PROMOTE EARLY GROWTH OF SODIUM CHLORIDE-INDUCED SALT STRESS SEEDLINGS OF BLACK CHERRY TOMATOES (Solanum lycopersicum L. var. cerasiforme)

Abstract

The black cherry tomato (Solanum lycopersicum L. var. cerasiforme) is an important crop, yet it is highly vulnerable to abiotic stresses, particularly salinity, which severely impairs seed germination and seedling growth. Mitigating the effects of salt stress is therefore critical for ensuring stable tomato production. This study examined the potential of spent tea leaf (STL) extract as a seed priming agent to alleviate the detrimental effects of salinity on seed germination and seedling development. Seeds of black cherry tomato were germinated in a growth medium containing NaCl at concentrations of 0, 2.5, 5.0, and 7.0 g/L. At 7 g/L NaCl, significant reductions were observed in germination rate, root length, shoot length, and the seed vigor index. To counteract these effects, seeds were treated with STL extracts derived from black, green, and oolong teas at concentrations of 1%, 2%, and 4%. Among these treatments, seeds primed with 1% oolong STL extract exhibited the most notable improvements across all measured parameters. The oolong STL treatment at 1% resulted in the highest final germination percentage, average daily germination rate, and Timson index under 7 g/L NaCl conditions. Additionally, significant enhancements in shoot length, root length, and fresh biomass were observed in seeds treated with oolong STL compared to those subjected to saline conditions without priming.