Mineral deficiencies in tomatoes

Even if you start off by applying nutrients according to a soil analysis, there is no guarantee that deficiencies of certain elements will not manifest later. Bill Kerr offers advice on spotting and treating common deficiencies.

- Bill Kerr

The levels of elements in soil vary constantly as conditions change. Nitrogen is particularly troublesome in this respect, as it is easily transported in its nitrate form by soil moisture. This means that if it rains heavily or the land is over-irrigated, and soil moisture moves below the root zone, the nitrogen will be lost to the plant.

If you are growing tomatoes using drip irrigation, you’ll need to be extra vigilant as it is easy to over-irrigate.

It is impossible to properly determine the depth of penetration by simply looking at the wet surface. You have to probe the soil or use tensiometers to determine the depth to which the irrigation water has penetrated.

A nitrogen deficiency usually starts to show on the older foliage.

IRON AND CALCIUM