Allotment Gardening Advice Help Chat

Growing => Growing in Greenhouses & Polytunnels => Topic started by: argonaut on July 16, 2020, 21:12

Title: Cucumber Disease
Post by: argonaut on July 16, 2020, 21:12

My Greenhouse Cucumber plant (min F1 all female) has developed what looks like brown scab on many leaves …. Is this Anthracnose ?  If so should I try and get some anti-fungus treatment.  Assume it was the Hot Wet weather last month.
Or should I take off the good fruit and destroy it.
They are container grown (Quad Grows) so it’s not in the soil.

Title: Re: Cucumber Disease
Post by: Aunt Sally on July 16, 2020, 21:22

Have you looked to see if there is anything nibbling it ?   Spider mite for instance.

Title: Re: Cucumber Disease
Post by: Aunt Sally on July 16, 2020, 21:28

Having looked at sone pictures of blight and anthracnose on cucumber leaves, it does look very similar.

(https://s3.amazonaws.com/plantvillage-production-new/images/pics/000/100/238/original/5481751-PPT.jpg?1490027447). (https://s3.amazonaws.com/plantvillage-production-new/images/pics/000/100/254/original/5481764-PPT.jpg?1490036166)

I’m not sure if there’s a fungicide available in the UK.

Provanto Fungus Fighter Plus  Has a picture of curcurbit on the bottle so that could be helpful

Title: Re: Cucumber Disease
Post by: argonaut on July 16, 2020, 21:36

I looked at some online pictures and the best fit seemed to be a fungus disease ... however several sites list different names ...either Anthracnose or Alternaria

Its producing loads of fruit - so shame to cull it.

Title: Re: Cucumber Disease
Post by: JayG on July 17, 2020, 09:52

I've always had a few leaves looking like yours, including this year - being cukes it could be almost anything, including sun scorch if exposed to full sunlight. Once the leaf is damaged it is prone to fungal attack - I just cut them off to avoid encouraging the spread of botrytis in the GH.

As long as the plant is still growing strongly and producing I wouldn't be unduly worried unless the number of unhealthy looking leaves overtakes the number of healthy ones.

Title: Re: Cucumber Disease
Post by: argonaut on July 17, 2020, 11:51

The new leaves start fine .... it seems they then get this once full size.

Title: Re: Cucumber Disease
Post by: JayG on July 17, 2020, 12:10

On fine days are they in full sunshine all day?

If so it's probably worth considering some form of shading (I use old bubble wrap hung in strategic positions to diffuse it a little.)

Title: Re: Cucumber Disease
Post by: argonaut on July 17, 2020, 12:25

They are in a greenhouse which has shading to the glass

Title: Re: Cucumber Disease
Post by: JayG on July 17, 2020, 14:40

Keep them well fed - I alternate a high nitrogen liquid feed with tomato feed.

Keep us posted as to how they do.