Watch out for this
The theme for this week’s Grower2Grower articles is ‘pest and disease pressure’. I have pushed back other articles as I believe it is incredibly important to stress to growers to be vigilant at this time. If you look after your crop now it will pay rewarding dividends in July and August. I have been told off, by my editor, as the articles are a bit doom and gloom (well it is winter!).
Late last week I came across cucumber plants whose leaves have on them what I suspect is a fungal infection, either a gummy stem blight, which attacks the leaf, or a Downey Mildew type fungus. This is an assumption I have made and can’t confirm without proper testing. My advice to the grower was to discuss product options with the local horticulture supplier in regards to applying a biological or chemical fungicide the following week. The problem with this disease is the speed with which it can cause damage. The weather conditions have been absolutely terrible over the weekend, with rain and warm humid weather aiding its spread. The structure they are growing in also lends itself to making life difficult.
Using your heating systems to aid in the control of excess condensation and high humidity is your best defence against disease pressure in the Winter. Even though it is quite warm it is still very important to keep a dry environment where possible. I would use heat and vent practice during this period or otherwise you could be in that spray suit a lot this Winter.
All of the above photos demonstrate the decaying and dying back of the leaf.