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Subject:  Yellow leaves on plant

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bluesilver

Tasmania Australia

Hi, i am not sure what has caused this or mainly what i am shirt of, thinking it could me Magnesium, but still a bit unsure.
Here is the link in my diary to the plant in question.
http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=251179
We have had a week of very hot weather,(above 30 c, 86 f)
It is a 1435 Wuersching, and has just been pollinated 2 days ago.
The other plant next to it planted a week later (1744.5 Fulk) doesn't seam to have any issues like this as yet.
I haven't had any fertilizer on either of them for about a week, so doesn't appear to be over fertilizing.
Any ideas would be greatly appreciated.
Cheers.

1/9/2016 6:23:36 PM

ACpumpkin

Tasmania, Australia

I recon magnesium, give the Epsom salts a try. Looks like you have sandy soil like I also have down south. I was pretty low in Mg on soil test this year. Cheers ac

1/10/2016 3:51:09 AM

Team Z

Germany

Was it very rainy or cold the days before? You also should check your stump. Mine was rotting..

1/10/2016 7:38:20 AM

Twinnie(Micheal)

Ireland

Could well be the cold

1/10/2016 8:08:24 AM

Condo*

N.c.

Hey Bluesilver!
If you have a magnesium deficiency a foliar application of 1 tablespoon Epsom salt to one gallon of water applied once this week and again in a week should rapidly make a difference in your leaf coloring. Another consideration I have is that you appear to have about a four foot walkway between your plants. The stump of your plant in relationship to the roots of your plant is much like the relationship between the hub of a bicycle tire and the spokes of the tire. The roots emerge from the stump in all directions and adjacent to your stump you appear in the picture to have a tromped down dry area bisecting prime rooting area.

1/10/2016 8:58:53 AM

removed_20180906

Valencia Spain

Not Cold, read above 86 The weather beforehand would of been 70f. Atleast

1/10/2016 1:01:23 PM

bluesilver

Tasmania Australia

I did think of Magnesium, gave it a foliar feed but at 2 tablespoons per gallon.
Will have to wait and see what that does.
Definitely not cold, hot enough her for watermelons to thrive.
The soil is a clay base soil, but has a lot of klep compost and mushroom compost spread over it.
Stump appears to look fine, but yes, i have a 4 foot walk way between the two plants that is pretty compacted.

1/10/2016 11:33:09 PM

Condo*

N.c.

Due to the fact that the yellow leaves seem to be tracking the main vine that would indicate more of a root/stump issue than a magnesium deficiency. Have you used a systemic like merit? Perhaps you have subterranean animals like voles. There are a lot of possible problems but a sudden heat wave coupled with insufficient water uptake could be stressing your plant. Consider that roots of a plant the size of your plant probably densely occupy a circle with a diameter of 16 feet. That in your case would be about 200 square feet. Your dry and compacted walkway occupies almost half of that area. It looks like you have soaker hoses set up to irrigate your patch but you are not using them. My thought is that your hoses should be about 2 feet apart not four feet. All that being said I am not convinced that the lack of sufficient water is causing your present problem as your plant looks like it is receiving damage or has suffered damage at or about the stump area. If nematodes, particularly root knot nematodes, are a known problem in your area you should think about testing your soil for these pests or contact an agricultural extension agent in your area for an evaluation.

1/11/2016 10:56:08 AM

Pumpking

Germany

Looks like the yellow leaves are leftovers from your plant problem from a couple of days ago, the new growth looks much better and the problem seems to be solved. You need to monitor the development of the leaves which are close to the yellow ones and which are still looking fine...find out if they develop indications of problems within the next couple of days or if they stay healthy.
The compacted soil of the path isn´t a great thing, but it probably isn´t the source of troubles. Many other growers plant their AG plants on one edge of the patch, which basically creates a similar situation...they simply don´t get the best out of their plants, but they don´t create a horrible stress situation for the plants even before the plant has a fruit growing (usuall plant stress begins when the fruit is adding 10-20 lbs a day or something like that).

...just my humble opinion.

1/11/2016 12:05:58 PM

bluesilver

Tasmania Australia

Cheers for the replies, Getting plenty of water, those drip lines are micro sprayers, spray out about 1/2 meter radius, so get plenty of cover.
Been keeping the main root area dry and patch is all fenced in so no animals can get near them.
Might try air rating the soil around the main stump, Plus next time i might need to make a raised walk way instead.

1/11/2016 3:58:31 PM

bluesilver

Tasmania Australia

Been an interesting few weeks.
Been foliar spraying epson salts at the rate of 1 tbs per gallon of water to the underside of the leaves.
So far nothing has changed except it is slowly getting worse.
Most of the leaves around the main steam are either yellow or dying off and can see the central steam easily now.
Had a closer look at the outside leaves, they have gone from the nice dark green color to a lighter shade of green.
Kind of looks like the main fruit is taking all energy from around the plant and absorbing it
(kind of the best way to describe what it looks like)
Fruit is at about the 57 lbs stage.

Was thinking maybe i might have to take a leaf to a lab to get a tissue test done on it.
Second plant looks to be just about to start doing it also, fruit was pollinated on the second one about 2 days ago.

Any more information is always greatly appreciated.
Cheers.

1/27/2016 9:30:40 PM

bluesilver

Tasmania Australia

Foliar spray should of read once a week.

1/27/2016 9:31:36 PM

Nana Rea

Massillon, Ohio

There are many reasons why plants' leaves turn yellow. I have found this helpful.

http://www.saferbrand.com/blog/plants-turning-yellow/?utm_content=

1/28/2016 2:57:26 PM

bluesilver

Tasmania Australia

Cheers for the link,
Appreciated.
All part of the learning curve to this hobby, trial and error.

1/28/2016 4:22:48 PM

bluesilver

Tasmania Australia

Thanks for the reply.
I have 2 photos of the underside and one of the top side of leavef.
http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=251470
http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=251471
http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=251472
There is two photos of underneath the leaf and one of the top of the same leaf to show the early stage of yellowing.

No fungicides have been sprayed on the patch or surrounding areas, Last years pumpkins grew ok, a little bit of die back, but nothing to this extreme.

Last year i planted mustard and oats as a cover crop.

I have a soil test here,

PH, 5.74
CECe 34.3 meq/100g
M3 PSR (ratio) 0.26
Base Saturation meg/100g 87.2
Exchangeable Acidity meq/100g 4.4 (12.8%CEC)
Aluminium Saturation % 6.00
Ca:Mg Ratio (ratio) 4.96
K:Mg Ratio 0.3

Mehlich Phosphorus 411.27 ppm
Potassium 531.76 ppm
Sulphur 686.0 ppm
Calcium 4661.55 ppm
Magnesium 569.87 ppm
Sodium 104.37 ppm
Chloride 18.75 ppm
Zinc 10.44 ppm
Copper 1.56 ppm
Boron 2.19 ppm
Manganese 42.3 ppm
Iron 275.684 ppm

Only thing soil test says is to add 3t/ha in lime
All information and help is greatly appreciated.
Cheers.

2/3/2016 12:22:41 AM

Pumpking

Germany

In addition to the low pH, which indeed could be closer to 7 in a better world, the total amount of ions (if all of them behave like easily water soluble) looks like a pretty salty soup.

2/3/2016 3:13:29 AM

bluesilver

Tasmania Australia

Yes, it definitely needs the lime to bring it up closer to at least 6.4, closer to 7 the better.
So it might be a case of a salt overload maybe? just way too much nutrients and not fully balanced out?

2/3/2016 3:28:19 AM

Pumpking

Germany

With the higher pH you will get rid of some of the excessive aluminium and iron and some of the other cations will then bind a bit stronger to the soil minerals. The other things...you need to water out the other salts. As long as you water too little (when watering your pumpkins), the water will penetrate into deeper soil layers (30-40 cm maybe) and upon evaporation it will migrate to the surface (by capillary action), will evaporate and thus be the elevator for the salts, ions from deeper soil layers will accumulate in the soil closer to the surface. If there isn´t much rain (which dissolves some of the salts and makes them drain away into much much deeper layers of your soil) you need to wash out the excessive salts from time to time. It probably isn´t the best thing to do that while the pumpkins are growing, you better do that at the end of your pumpkin season. In spring you should get a new soil test done which will then tell you which nutrients need to be added (or if there is still plenty or too much of everything).

2/3/2016 6:50:30 AM

bluesilver

Tasmania Australia

All makes pretty good sense.
I am thinking the recommended 3t/ha of lime would go a long way to help that.
All a good learning curve that is for sure and always some pretty good and helpful advice which is always appreciated.

Just a matter of keep watering it for this season and not add anything else till the season is finished.
Still putting on some good amounts of weight per day.
Cheers.

2/4/2016 12:17:25 AM

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