Effects of constant and fluctuating salinity on the yield, quality and calcium status of tomatoes

SummaryTomato plants were grown in nutrient film (NFT) at constant salinities of 3, 5.5 and 8 mS cm−1 and also with the salinity fluctuating from 8 mS cm−1 during the day to 3 mS cm−1 at night (the 8/3 mS treatment). The yield was always depressed at 8 mS cm−1. During the first four weeks of harvesting this was mainly due to reduced fruit size, but later fruit number also decreased. The 8/3 mS treatment reduced fruit size and number more than a constant 5.5 mS cm−1 (the average of the fluctuating salinities), suggesting that 8 mS cm−1 affected the long-term development of the plants. Increasing the salinity by addition of either major nutrients (K, Mg, Ca and NO3–N) or NaCl gave similar responses. The sugar and acid contents of the fruit juices increased with salinity but these responses disappeared when the data were expressed on a dry matter basis. This lack of response to salinity was confirmed by the sugar analyses of fruit after freeze-drying. Increasing the salinity with NaCl depressed the K content...

[1]  L. Ho.  The Relationship Between the Rates of Carbon Transport and of Photosynthesis in Tomato Leaves , 1976 .

[2]  W. Pill,et al.  Effects of soil water regime and nitrogen form on blossom-end rot, yield, water relations, and elemental composition of tomato. , 1980 .

[3]  G. Winsor,et al.  Effect of nitrogen, phosphorus, potassium, magnesium and liming on the composition of tomato fruit , 1967 .

[4]  G. Winsor.  SOME FACTORS AFFECTING THE QUALITY AND COMPOSITION OF TOMATOES , 1979 .

[5]  G. Steucek,et al.  Phloem mobility of magnesium. , 1970, Plant physiology.

[6]  D. Ehret,et al.  The effects of salinity on dry matter partitioning and fruit growth in tomatoes grown in nutrient film culture , 1986 .

[7]  D. Ehret,et al.  Translocation of Calcium in Relation to Tomato Fruit Growth , 1986 .

[8]  D. A. T. Southgate,et al.  McCance and Widdowson's The Composition of Foods. 4th edition. , 1978 .

[9]  A. Picken,et al.  An analysis of the accumulation of water and dry matter in tomato fruit , 1987 .

[10]  C. Guttridge,et al.  Effects of night time humidity and nutrient solution concentration on the calcium content of tomato fruit. , 1984 .

[11]  P. Adams,et al.  EFFECT OF SALINITY AND WATERING LEVEL ON THE CALCIUM CONTENT OF TOMATO FRUIT , 1986 .

[12]  A. Poljakoff-mayber,et al.  Changes in growth and water-soluble solute concentrations in Sorghum bicolor stressed with sodium and potassium salts , 1984 .

[13]  J. Rudich,et al.  Low Water Tensions in Defined Growth Stages of Processing Tomato Plants and their Effects on Yield and Quality , 1977 .

[14]  P. Adams,et al.  Effects of Diurnal Changes in the Salinity of the Nutrient Solution on the Accumulation of Calcium by Tomato Fruit , 1989 .

[15]  L. Ho.  Environmental Effects on the Diurnal Accumulation of 45Ca by Young Fruit and Leaves of Tomato Plants , 1989 .

[16]  G. Hobson,et al.  The constituents of tomato fruit--the influence of environment, nutrition, and genotype. , 1981, Critical reviews in food science and nutrition.