Understanding Tip Burn in Hydroponic Lettuce: Causes, Symptoms, and Prevention

By Giulio Gabrieli

Tip burn is a calcium-related disorder that results in necrotic areas on the inner leaves of hydroponic lettuce, which can significantly impact the health and salability of the lettuce crop. It can also lead to poor yield and quality in the long run. In this post, we’ll discuss what tip burn is, its causes and symptoms, and how to prevent and treat it in hydroponic lettuce.

What is Tip Burn?

Tip burn is a physiological disorder that causes the edges of lettuce leaves to brown and die back from the tip. It typically affects the innermost leaves of hydroponic lettuce plants, but can also impact the outer leaves in severe cases. Tip burn is caused by a deficiency of calcium in the growing medium, which leads to the development of necrosis in the leaf margins.

Causes and Symptoms of Tip Burn

The principal cause of tip burn in hydroponic lettuce is a calcium deficiency in the growing medium. The deficiency can result from several factors such as salt buildup, high humidity, low light intensity, high temperature, or sudden changes in temperature. When the calcium level is low, it creates stress in the plant that results in the necrosis of leaf margins.

The symptoms of tip burn include the browning of the leaf margins, making them crispy and dry. Initially, the affected leaves may appear to be water-soaked, but over time, the color of the affected areas turns brown or black, and the tissue becomes dry and brittle. In severe cases, the leaves may rot, and the plant may become stunted.

Preventing and Treating Tip Burn

Prevention is always better than cure, and in the case of tip burn in hydroponic lettuce, it can be prevented by maintaining proper growing conditions. Here are some tips to prevent and treat tip burn in hydroponic lettuce:

  • Ensure adequate calcium levels in the growing medium.

  • Reduce or eliminate the use of high-nitrogen fertilizers, which can interfere with calcium uptake.

  • Control humidity levels, as high humidity can cause the plant to transpire excessively, leading to water loss and calcium deficiency.

  • Maintain optimal light conditions for the plant, as low light levels can reduce photosynthesis, leading to calcium deficiency.

  • Provide consistent temperature conditions to avoid sudden fluctuations, which can cause stress to the plant.

Cover image by Giulio Gabrieli on Unsplash