Tomato Salinity

A few years ago I was operating a small greenhouse on the Greek Isles, a place where wind and heat become your enemy. We grew 45 varieties of tomatoes, many heirloom and the end result was near perfect despite some mishaps here and there.

One of the secrets to growing tomatoes is the use of brackish water, a certain percentage salty water, which helps the tomatoes grow more sweet.

Salinity in soil is measured by passing an electrical charge between two electrodes with a soil sample in between. Salt increases conductivity, so the salinity of the soil can be measured by how well the electricity transmits between the two points.

According to the Journal of Agricultural and Food Chemistry, scientists discovered that a diluted seawater solution actually had a beneficial effect on cherry tomato fruits, probably because of the slight stress caused on the plants.

Plants were watered with 10 percent seawater and fresh water after they had been growing for three weeks and were past the stage where the seawater would kill them. The red-ripe tomatoes were tested for flavor and nutrients, and the scientists discovered significant improvements in both.

The tomatoes’ weight was slightly lower but they were sweeter and tastier because of the increased sugars and acidity. They were also higher in ascorbic acid, vitamin E and antioxidants.

After all, a tomato is more than 85% water and if you roast a tomato you will extract and concentrate the flavors.

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