Manoa lettuce is a lettuce variety susceptible to tipburn. Tipburn is the drying and dying of leaf tissue along the edges of the leaf. During a test at a grower in Hawaii it was shown that by increasing the DO levels and adding ultrafine bubbles, reduction of tipburn is realized and quality and production improvements are made.
Tipburn of lettuce is the drying and dying of leaf tissue along the edges of the leaf. The first symptoms of damage consist of small yellow spots or edges along the leaf edge. Usually they are not found on the oldest leaf, but more on the growing, younger leaves of the head. The damage generally occurs only after a head has formed. The moment when the leaves of the head loosen, is critical for the occurrence of the damage. The very tallest leaves are usually cool. As the deterioration continues, the spots expand and unite, while the tissue disappears. This causes irregularly shaped dead and thinned leaf edges. These often form a starting point for secondary parasitic infections (bacterial rot).
IR L. J. J. van der Kloes, Proefstation voor de Groenten- en Fruitteelt onder glas te Naaldwijk (translated from Dutch)ci 1