A pox on my pumpkins!

[Randall]

All,

I am growing Chinese/Japanses pumpkins in Western Australia.
They are growing ok and flowerbuds have started to come but I have noticed that the leaves near the root-base of the vine are turning yellow at the edges, going brown and dying.

Also, along the veins of the leaves the leaf tissue is turning clear, as if the fluid-equivalent of blood coming into the leaf and killing the chlorophyll. Some of the leaves have whitish blobs on them, not unlike mould.

This 'pox' seems to be travelling along the vine from the root end. Leaves are dying off steadily along the vine although new leaf-stalks are budding.

I can send photos. No sure how to get them into this post though.

Any tips?

They get a lot of water directly on their roots.
The soil is mostly sand with some humus (land was previously a market garden)
There is a shade cloth to baffle the vicious WA sun

Cheers
R

[Kisal]

Welcome, Randall! I'm sorry I don't have advice about your pumpkins, but I know pictures would be a great help to our members. You can find instructions for how to post pictures on forums at the link below:

[url=https://www.helpfulgardener.com/forum/viewforum.php?f=23]Helpful Gardener's Tips & Suggestions for New Members[/url]

[applestar]

Do you have squash vine borers in Australia? The adult moth lays eggs at the base of the squash and pumpkin vines and the larvae burrows in the stem near the base, then chew their way up the plant. Look for timy holes with sawdust like particles. What you describe could be early symptoms, followed by a sudden wilt. By that time the plant can't be saved.

The white spots could well be mildew - powdery or downy. If it's in early stages, spraying with milk solution, mixed 1 milk : 8 water may help. If you have compost, compost tea spray helps too.

Kisal is right though, one good photo speaks 1000 words....

[rainbowgardener]

Here's the instructions on how to post pictures:

https://www.helpfulgardener.com/forum/viewtopic.php?t=3724

agree with applestar that the white part sounds like powdery mildew, which squash and pumpkins are fairly prone to. If you type powdery mildew into the Search the Forum feature, you will find lots written about it.

A bad case of powdery mildew does eventually lead to older leaves yellowing and dying, so I'm not sure if you have the mildew and something else or not.

[Randall]

Ok, here goes...

[img]https://img689.imageshack.us/I/plaguedpumpkin.jpg/][/img]

Link:
https://yfrog.com/j5plaguedpumpkinj

Thanks for all the tips...


Randall

[gixxerific]

how about this!:D

[img]https://img689.yfrog.com/img689/6298/plaguedpumpkin.jpg[/img]

Sorry can't help much with plant problem. I looked trough 2 books now and that looks closest to scorch, too much heat. But you said there is mold like signs so that probably isn't it, it also kinda looks like potassium deficiency with the discoloration. I could be way off though.

[Randall]

Thanks Gixxerific.

I'm trying to work out if the yellowing is related to the mildew or not. My pumpkins are dying by inches at the moment and I am hoping the one flower I have blooming is not going to be the last.

Is this the effect of mildrew or someting else?

Thanks in advance....

[gixxerific]

looking further into what I wrote above I found this, again it might not be the problem but best I can come up with.

From Rodales: Controlling Pest and Disease -

Potassium deficiency: Older leaves begin to show yellow patches first, with brown tips and many brown patches near the margins. Leaves appear scorched and have ragged edges as dead tissue from the edges falls away. Symptoms may be confused with bacterial wilt or some fungal diseases. Plant growth is poor, leaves are smaller than usual, and shoots are thinner.

Good luck

[serial_killer]

From Rodales: Controlling Pest and Disease
Good luck

Is this available online somewhere, or do you have the book?

[gixxerific]

It was in a few books I have but [url=https://www.extension.umn.edu/yardandgarden/diagnostics/mainvegetables.html]this[/url] kinda looks like it too.
[img]https://www.extension.umn.edu/yardandgarden/diagnostics/Images/veggiedisease/cucumberanthracnose-pdc.jpg[/img]
Anthracnose can form lesions on seedlings, leaves, petioles, stems and fruit of susceptible cucurbits. Lesions appear somewhat angular and red-brown, and dead tissue
in the center of the lesion may drop out

[Kyt]

Randall,
May ask what kind of fertilization program you are using on your pumpkins. My husband grows Giant Pumpkins here in Southern Georgia and he has to battle the heat, powdery mildew, wilt, and everything imagneable. Maybe if I knew what kind of fertilization program you was using. I could help you a little more with your problem.

Also, are you watering during the day overhead or spraying any pesticides during the day overhead.

The yellowing most likely is a cause of a iron deficency.

A little information would be helpful to assist with your problem.

[Kyt]

I had my husband come and look at the picture you had posted. He said it was a disease. What you needed to do is cut off the affected leaves get them away from your patch and burn them. If you have plants that are oozing that it is a soil born disease.

[Randall]

Wow, thanks for all the help!

Kyt: If there's one thing Western Australian soil is not lacking it is iron (we export it as iron ore to China). Potassium though.. not sure how to combat that, short of blend-up some bananas...

I fertilise with something called 'Charlie Carp' (European carp are a pest in Australia so they catch them and blend them into fertiliser...) which has K in it.

I've noticed healthy leaves growing out of the main vine so I'll cut off my unhealthy ones.

Thanks all
Randall