[Y.E.A.H]

when i went to water my plants today i noticed one of my butternut squash had this odd pattern on the leaf, it's started spreading onto another butternut squash so i've taken the two plants away from the rest of my squashes. i did look for bugs but there was nothing there. i haven't over watered them and i haven't under watered them. i just can't think of what it could be.

please help 

what ever it is, will it effect other squash ?

thanks in advance

[8doubles]

It looks like water splash marks and sun scorching to me , nothing too serious i hope.

[pink aubergine]

When I saw this post I wondered if you had the same as me which was a chlorosis which I thought had been caused by a virus (altho I realise too early to be transmitted by aphids so thoought it was in the seeds) . Howeveer only the first couple of leaves were suffering this and subsequent leaves recovered.

I agree with 8doubles that it could be sun scorching due to watering in full sun. Can avoid this by watering pot only and not leaves; or watering early morn or in eve.

The other thing it could just be is mildew, I think this because from Pic it not only looks you have some pale spots on leaf but also as though the leaf is curling up from the bottom. if this is so, I would suggest you improve the air flow round them - so not cover them with propagator cover, move plants further apart to maximise air flow, leave a greenhouse door slightly ajar or a window slightly open..... Remember hot air  rises so if there can be a slight movement in the air, this will help the health of the plants.

In my polytunnel I have a door at either end, there are gaps round the door at the lower end, the tunnel is on a slight slope so the hot air rises and a solar fan continually pulls the air through. We have had no fungal diseases at all since this was installed.

best of luck!

[Y.E.A.H]

thanks guys  

these patches on the leaves were thinner than than the rest of the leaf
just thought i'd say  

[pink aubergine]

I'd go with the scorch then, the mildew tends to have a slightly powdery finish to the patch, sometimes even furry!

[sunshineband]

Not mildew, don't worry 

[Y.E.A.H]

nothing too serous then, that's good to know  thanks