From

Location

Message

Date Posted

Illinois

Hi everyone,

I have a nice four lobe fruit which was pollinated 8 days ago. It is growing nicely but on day 5, I noticed the leaves at the base of the plant turning yellow and brown. I came back yesterday (two days later) and they have all died... there are no leaves within 1' of the original planting location. And now I see that the next leaf up the vine is starting to turn yellow.

What is causing this and how do I fix it? I'm guessing this is a lack of potassium? However, I balanced my soil at the beginning of the year and added the right amounts of micro and macro-nutrients to fix any deficiencies.

7/29/2014 10:32:02 AM

Farming- a bunch of catastrophies that result in a lifestyle

Post a pic, but it doesn't sound nutrient related......usually nutrient issues take time, weeks, to 'kill off' leaves. This sounds like a disease to me. If you can put up a picture, people will be able to help you better. Try to add what you are spraying the plants with/frequency of. Watering conditions, ect. Nutrient deficiencies don't cause leaves to die in two days that I am aware of.

7/29/2014 10:50:14 AM

Illinois

Good idea. Here you go:

http://imgur.com/qTUpos5

7/29/2014 11:00:43 AM

Illinois

As for watering, I've been keeping it consistent at around 2" per week (adding whatever the rain didn't bring). I spray with a dilute mixture of seaweed powder and fish fertilizer once per week. That's it!

7/29/2014 11:09:34 AM

Springfield, VT

Is it possibly spidermites ?

7/29/2014 11:19:16 AM

Illinois

I don't think so. I checked the underside of the leaves with a magnifying loupe and don't see any insects. Here's a pic I took of the underside of small leaf in the original pic that is yellowing. The black stuff appears to just be dirt.

http://imgur.com/380r1BB

7/29/2014 11:34:18 AM

Illinois

I thought I would add that all of the other vegetables in the garden are doing really well... it's the best year ever for me. We have potatoes, grapes, blueberries, strawberries, garlic, onions, and broccoli.

7/29/2014 11:36:21 AM

Illinois

Hey, I just noticed that the bottom leaves of the broccoli are turning brown... pics I've seen online suggest nitrogen deficiency... is that a possibility?

7/29/2014 11:40:43 AM

Anamosa, IA BPIowegian@aol.com

Nitrogen deficiency is definitely a possibility with 2" of water per week, especially if you are using an inorganic form of nitrogen. It can leach out. Organic sources like compost, manure and a prior legume crop stay in the soil better. One inch per week is usually adequate, unless you have sandy, excessively drained soil. And that increases the leaching. It is possible that you have some kind of fungal disease. Do you use any fungicides? Maybe someone else has a better idea.

7/29/2014 1:07:23 PM

Farming- a bunch of catastrophies that result in a lifestyle

LOL, cool leaf close up!! Anyway. I think it is more an overall look at the plant that's needed. N deficiency (someone swat me if I'm wrong) shows up in the older leaves first and progresses 'down' the plant towards younger leaves. In a pumpkin, and in your first pic it does look as though the 'older' portion of the plant is more yellow than the 'younger' portion. I still maintain though that those leaves in pic that are all brown in 2 days isn't just N problem. Could be where the issue with the leaves started, but that looks like an advance fungal infection of some sort. Gummy stem blight shoots to mind because of the leaf just ahead of those that has the characteristic browning. I don't think it's an advanced case of anthracnose....not 'speckly' enough....sorry, I lack the scientific terminology....Could be Downey Mildew, pic not close up enough in first pic to see if the 'mottling' is there that is characteristic of it.
You said your spraying with a dilute mixture of seaweed and fish once a week. maybe the stress of lack of N leads to more rapid decline by the fungus around? You have a soil test done recently? 2' of water a week is a lot, especially if like Io suggested, and your soil is real sandy. Did you balance soil in the spring with man made or organic ferts?

7/29/2014 3:12:57 PM

Illinois

Hi LB,

Yes, I had a soil test done in the spring and balanced out with synthetic fertilizers. However, I also sheet mulched with top soil, peat moss, and various green and brown plant matter. The pumpkin is mostly in this area. The native soil (Midwest) is rich in organic content but is heavy clay.

I don't think this is downy mildew... didn't see the characteristic color on the leaves. They simply started browning and died very quickly.

It has been raining a fair amount and the soil is moist. However, it is a raised bed (6") with good drainage.

7/29/2014 3:21:00 PM

Illinois

Ah, I should've mentioned that I used cow manure when sheet mulching as well.

7/29/2014 3:21:37 PM

Farming- a bunch of catastrophies that result in a lifestyle

Wouldn't hurt to get a quick soil test done, this time of year they come back pretty quick from our extension office. Are leaves still turning brown like that pic in just 2 days? Generally only a fungus moves that fast

7/29/2014 3:28:03 PM

Illinois

It's possible that I just didn't notice it, but there were leaves there a few days ago, I'm sure of it. The last photo I have was taken 19 days ago and there is an edge of one of the first leaves which had turned brown for a few inches.

I guess we'll see in a day or two...

7/29/2014 3:46:58 PM

Connecticut

To me this looks like plant stress related to nitrogen deficiency. The image in the link does not seem to indicate any disease. This is typically seen this time of year and becomes more evident when there is a growing pumpkin.

I suggest some blood meal (two hand fulls) sprinkled lightly under the plant and then watered in. You can use Urea or Calcium nitrate, but these are more concentrated and growers tend to over add these materials, the blood meal is only 12% N vs Urea that is 48% N

One advantage to nitrogen is that it is quick acting and you should notice a slow down in the yellowing (if it is nitrogen) only 3-5 days after watering in the blood meal.

With the information presented I am favoring N deficiency and not a disease, so that is positive.

7/30/2014 10:03:05 PM

Illinois

I applied some old tomato fertilizer (fairly balanced) I had sitting around the day I wrote this. Yesterday, I also applied an foliar application of Miracle Grow yesterday.

I haven't seen any more damage to the plant so its looking good...

7/31/2014 12:02:46 PM

Illinois

Looking good. Pumpkin is not growing at the same rate as last year (it's been cold and there's not as much salad). However, it put on 3 lbs yesterday and the leaf rot has completely stopped.

I'd say it was almost definitely a nitrogen deficiency.

8/3/2014 8:32:35 AM

Farming- a bunch of catastrophies that result in a lifestyle

I love being wrong when it turns out good.

8/3/2014 4:57:52 PM