Foliar smoke-water application improves growth and changes the leaf mineral composition of radish, spinach and turnip seedlings

•Smoke–water (1:2500 v/v) foliar application was tested on radish, spinach and turnip seedlings.•Essential mineral elements were determined in the leaves of seedlings of these vegetables.•Smoke–water significantly stimulated the length and weight of seedlings of examined vegetables.•Potassium and zinc levels were markedly improved in leaves with smoke–water.•Smoke–water, a promising technology for growing vigorous vegetable seedlings. Smoke–water, a smoke-saturated solution derived from the smoke generated by burning plant materials, promotes seed germination and growth of various plant species. There are many reported studies where seeds are treated and soils are drenched with smoke–water to explore the beneficial effects of smoke. However, little information is available on the influence of foliar spraying of smoke–water on the seedlings of commercial vegetable crops for better growth prospects. This study, therefore, investigated the effects of standardized smoke–water (1:2500 v/v) foliar application on the seedling growth of radish (Raphanus sativus L.), spinach (Spinacia oleracea L.) and turnip (Brassica rapa L.), and determined the mineral elemental composition of leaves. Smoke–water foliar treatment significantly enhanced the length and weight of seedlings compared to the seedlings sprayed with water (control). Mineral elements, potassium and zinc, were increased notably in the leaves of all smoke–water foliar-treated seedlings. This can be attributed to increased photosynthetic activity that resulted in longer and heavier seedlings. The results of the present study provide an opportunity to incorporate the use of smoke–water for raising vigorous and healthier vegetable seedlings for better yield. Moreover, it can minimize the input of conventional chemical sprays that are detrimental to the environment.