Soluble salt and ammonium injury on tomato seedlings

Soluble salt and ammonium injury on tomato seedlings

Tomato seedlings are for the most part are easy to grow, but every so often a problem will arise. Distorted leaves and aborted growing tips can often be explained away with evidence of herbicide use in or nearby a greenhouse or a virus originating from the seed. In this case excess fertilizing is more likely the cause.

The problem developed in a growers greenhouse affecting 90% of the crop. The tomato seedlings were in 12 inch patio pots, 3 plants in each pot. A soil test was completed on the soilless mix and the results indicated a soluble salts of 3.04 mS/cm, an ammonium nitrogen level of 46 ppm and a sodium level of 101.2 ppm.

Tomatoes in general can tolerate high salts and high ammonium levels but tomato seedlings 3 to 4 weeks old can be damaged. Leaching the soil with clear water and changing the fertilizer to a higher nitrate form is the recommendation but the plants will need to be watched to see if the new growth will return to normal.

Fact Sheet
Growing Vegetable Bedding Plants

Photo Library: