PROBLEM TO BE SOLVED: To provide a liquid fertilizer to improve the sugar concentration of tomatoes by making the effective use of the potential of brown sugar, and having no environmental pollution； and to provide a method for manufacturing the same and a method for using the same.SOLUTION: A yeast of Saccharomyces of 1 to 3 pts.mass is added to 100 pts.mass of a brown sugar aqueous solution of 30-40 mass%, and fermented； Rebaudioside A of 2 to 4 pts.mass is added thereto to make a sugar concentration-improving liquid fertilizer of tomatoes, which is diluted 500 to 1,000 times with water； and the diluted sugar condition-improving liquid fertilizer of tomatoes is sprayed on a culture medium surface in a container on which seedlings of tomatoes are planted during the period when the yeast of Saccharomyces ferments.【課題】トマトの糖度を上昇させるための、環境汚染のない、黒糖のポテンシャルを有効に活用したトマトの糖度向上液肥、その製造方法及びその使用方法を提供する。【解決手段】３０～４０質量％の黒糖水溶液１００質量部に対し、１～３質量部のサッカロミセス属の酵母を加えて発酵させ、これに２～４質量部のレバウディオサイドＡを加えたトマトの糖度向上液肥を水で５００～１０００倍に希釈し、このトマトの糖度向上希釈液肥を、サッカロミセス属の酵母が発酵している期間中にトマトの苗を定植した容器の培地表面に散布する。【選択図】なし
