Abstract
Lebanon's land mostly consists of carbonate rocks, which are generally calcareous. Calcium carbonate is not easily penetrable by vine roots except via cracks. Farmers resorted to the application of the conventional chemical calcium fertilizer. The study compared the effect of a conventional Ca fertilizer to two organic Lithovit Nano-Ca fertilizers on "Tfiefihi" variety. These products were applied once or twice. Shoot length, leaf number and composition, berry characteristics, and production indicators were investigated for two consecutive years. The highest shoot length was induced by the two-time application of Lithovit standard (T6) (346.70 cm). One-time application of Lithovit Amino25 (T3) recorded the highest leaf number (206 leaves). One-time application of Lithovit standard (T5) increased phosphorus in leaves by 0.04%. The lowest sugar content at harvest was detected in T5 and the highest one in T6. The two-time application of Lithovit Amino25 (T4) caused the highest delay in veraison (26 d). T3 recorded the highest acidity content in berry (3.83%). Nano-fertilizer has hastened harvest by around 25 d compared to conventional Ca fertilizer. T3 significantly reduced the cluster weight compared to all treatments and reduced the yield. Lithovit standard could be a beneficial substitution to the conventional fertilizer especially when applied twice.