## 3 Results and Discussion
### Tomato Fruit Refractometric Index \"Brix\"  
The total soluble solids--TSS (% Brix) of tomato fruits was significantly affected (Pr < 0.0001) by salinity levels and storage conditions, for all tomato varieties. Moreover, the mean values (% Brix) recorded at high salinity (S-3: 9.5 dS m\({}^{-1}\)) were significantly higher than those recorded at medium (S-2: 6 dS m\({}^{-1}\)) and low (S-1: 2.5 dS m\({}^{-1}\)) salinities, for all tomato varieties (Table 2). The results obtained in this study showed that increasing salt concentrations in irrigation water leads to an increase in the sugar and TSS contents in tomato fruits, and this is accordance with the study by [PERSON] et al. [40]. Also, [PERSON] et al. [41] stated that higher salinity level leads to improved tomato fruit quality by increasing the TSS and sugar contents. Although no significant differences were recorded in the TSS values between the three tomato varieties, the highest mean value (% Brix) was recorded for the Gandhowra-F1 (7.79%), followed by the Forester-F1 (7.49%), and the least mean value was recorded for the Feisty-Red (7.36%). On the other hand, the results showed statistically significant changes (Pr < 0.0001) in the TSS as a result of changes in the storage conditions compared to the control treatment (fresh fruits). Moreover, at storage temperature of 12 \({}^{\circ}\)C, the highest TSS value (8.19% Brix) was recorded for the Ghandowra-F1 variety on the 24 th storage day, while the highest TSS \begin{table}
\begin{tabular}{l l l l} \hline \hline \multirow{2}{*}{**Tomato Varieties**} & \multicolumn{3}{c}{**Salinity Levels**} \\ \cline{2-4}  & **S-1 (2.5 dS m\({}^{-1}\))** & **S-2 (6.0 dS m\({}^{-1}\))** & **S-3 (9.5 dS m\({}^{-1}\))** \\ \hline Ghandowra-F1 & 7.25 \({}^{\circ}\)\({}^{*}\) & 7.87 \({}^{\mathrm{b}}\) & 8.24 \({}^{\mathrm{a}}\) \\ Forester- F1 & 6.91 \({}^{\mathrm{c}}\) & 7.68 \({}^{\mathrm{b}}\) & 7.89 \({}^{\mathrm{a}}\) \\ Feisty-Red & 6.94 \({}^{\mathrm{c}}\) & 7.35 \({}^{\mathrm{b}}\) & 7.80 \({}^{\mathrm{a}}\) \\ \hline \hline \end{tabular} \({}^{*}\)Means with different letters indicate statistically significant differences at the 0.05 significance level (LSD\({}_{10.05}\)).  
\end{table} 
Table 2: The effect of salinity levels on the TSS (% Brix) for the three tomato varieties. values for Forester-F1 (7.83% Brix) and Feisty-Red (7.82% Brix) were recorded on the 16 th storage day and at a temperature of 12 \({}^{\circ}\)C (cold storage). In the case of storing tomato fruits at room temperature (22 \({}^{\circ}\)C), the highest TSS values were recorded for Ghandowra-F1 (7.84% Brix) and Feisty-Red (7.56% Brix) on the 12 th storage day, while the highest TSS value for Forester-F1 (7.63% Brix) was recorded on the 8 th storage day. These results were in line with the finding of [PERSON] et al. [35], which showed an increase in the TSS during the storage periods. In general, a slight decrease in Brix content was noted at room temperature (22 \({}^{\circ}\)C) compared to cold storage temperature (12 \({}^{\circ}\)C). Overall, TSS content of the Ghandowra-F1 and Forester-F1 varieties increased by 6.4% and 4.2% after 24 days of storage, while it decreased slightly with the Feisty-Red variety. [PERSON] et al. [42] reported that the significant changes in the TSS of tomato fruits at different storage conditions may be attributed to the hydrolysis of carbohydrates to soluble sugars and the high water loss during storage periods. Figure 2 shows the TSS results for tomato fruits for different combinations of salinity levels (S-1, S-2, and S-3) and storage treatments (ST-0 to ST-9) for all varieties. The highest mean TSS value (9.12% Brix) was recorded for Ghandowra-F1 for the combination S-3/ST-8, with no significant difference from TSS (8.80% Brix) recorded for the combination S-2/ST-9, while for Forester-F1, the highest mean TSS value (8.49% Brix) was associated with the combination S-2/ST-7, with no significant difference from the TSS value (8.39% Brix) obtained with the combination S-2/ST-8.