EFFECT OF POTASSIUM NITRATE AND SULPHATE ON GROWTH,ROOT MORPHOLOGICAL TRAITS,POTASSIUM UPTAKE AND UTILIZATION EFFICIENCY OF TOMATO SEEDLINGS

Water culture experiments were conducted to investigate effect of potassium on seedling growth,root morphology traits and potassium uptake and physiological K use efficiency with different potash(KNO3,K2SO4),different K levels(0.0 mmol/L,2.0 mmol/L,4.0 mmol/L and 8.0 mmol/L) and two varieties(TFGL,MF802).After treated with the levels of 4.0 mmol/L and 8.0 mmol/L,root length and plant height of tomato plants were significantly higher than that treated with potassium sulphate.At the level of 8.0mmol/L,the number of tomato root tips with potassium nitrate was significantly higher than that with potassium sulphate in TFGL.K content and the root diameter of plants treated with potassium sulphate was significantly higher than treatments with potassium nitrate in MF802.Results showed that potassium treatment with 8.0mmol/L was the most suitable for tomatoes.Potassium nitrate is beneficial to the growth and development of tomato,and potassium sulfate is sensitive to potassium absorption.Under the treatment with the same potassium level,no significant difference was found in the fresh weight and dry weight of two different tomato varieties.