Wageningen, The Netherlands
December 21, 2011

Source: Wageningen UR Greenhouse Horticulture

Tip burn of tomato leaves is often seen by growers as indication for maximum crop performance, however grey mould (botrytis), can easily infect through the necrotic leaf edges. In this desk study factors that are influencing the occurrence of tip burn and calcium (Ca) deficiency were studied. The project was funded by the Product Board of Horticulture.

Cells formed during periods of Ca shortage have weaker membranes and walls and ‘burst’ after a climatic shock resulting in plasmolysis and disintegration of the membranes. Possibly the disruption of the Ca homeostasis in the cytoplasm. Botrytis uses dead tissue as an entrance to infect the plant. The weak cell walls and solute leaking caused by disruption of the membranes facilitates the infection process of the fungus. Ca uptake and transport are affected by high fruit load, EC and K/Ca in the root environment and transpiration and root pressure. These factors sometimes interact and sometimes are independently effective, resulting in a complex situation. Thus preventing heavy fruit loads in susceptible periods and stimulating Ca uptake and distribution will alleviate the problem. This, in combination with the prevention of climate shocks will help to reduce the occurrence of tip burn in tomato.

This report is only available in Dutch: www.tuinbouw.nl

Website: http://www.wur.nl

Published: December 21, 2011