Tipburn primarily impacts leafy greens, such as lettuce, Swiss chard, and cabbage, thriving within the controlled microclimates of greenhouses. It emerges as a result of environmental factors, primarily a localised calcium deficiency in the rapidly growing tissues. Calcium is vital for cell wall integrity, and when in short supply, it weakens plant cells, leading to the hallmark symptom of Tipburn - the necrosis of leaf edges.
The initial signs manifest as browning along the sides of the leaves, especially on the youngest, rapidly growing leaves. The affected areas may appear dry and papery, eventually leading to tissue collapse. Underlying factors, such as fluctuations in humidity (low a night and high during the day), fluctuations in temperature, or inconsistent water supply, often worsen Tipburn. Important to note, leafy greens that are affected by Tipburn are still perfectly edible and do not create any issues for people who consume them. The bigger problem is your customers thinking you produce is of lower quality and paying you less for your harvest, so you are better of getting rid of the affected lettuce heads to keep up the premium feeling of your produce.
How to prevent Tipburn
Nutrient Management: Maintain proper Calcium levels through precise nutrient level management in your water supply. Regularly test and adjust the Calcium supply meeting the specific needs of your crops.
Temperature Stability: Prevent drastic temperature fluctuations, which can stress the plants and hinder Calcium utilisation.
Monitor Electrical Conductivity (EC): Regularly measure EC levels to assess nutrient availability and ensure an appropriate Calcium supply. You can do this for example with sensors from our partners at Sigrow or Aranet.
Manage Liming: to control Tipburn you need to manage liming so that soil pH is always above 6.0 (limit ammonium forms of nitrogen).
Production planning: Tipburn is less likely to occur when head maturation occurs during cooler temperatures. You can adjust yearly planning for this and also adjust you HVAC computer to reflect the specific stage of growth of your produce.
If you are aware of Tipburn and make sure you regularly check your equipment you too can have a Tipburn-free harvest.