Bacterial blotch is actually an annually recurring problem and each autumn causes trouble for many growers. Often spraying is reduced This doesn’t always makes sense as mushrooms need water and the casing soil may dehydrate completely if there is too little or no spraying with all the inherent consequences. What should you do instead?
Spraying less in the preparation stage does not have much influence on the later development of bacterial blotch. During this phase it’s better to pay attention to the compost and growth in the casing soil combined with the amount of caccing.
Spraying the mushrooms less only has sense if the number of spraying moments is reduced. Instead of spraying 3 litres on two consecutive days it’s better to spray 4 or 5 litres on one day.
It’s essential that the bed surface does not remain soaked for longer than strictly necessary. After all bacteria are perfectly at home in damp conditions. For this reason too using a drying program is recommended in the autumn.
John Peeters, C point