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Produce => Under Glass => Topic started by: Smileyk on July 18, 2007, 22:34:54

Title: Yellow patches on Tomato leaves?
Post by: Smileyk on July 18, 2007, 22:34:54: My tomatoes have yellow patches on the leaves - any idea what it is?

I feed them once a week so assumed they weren't lacking in anything but something is wrong. I've had this before and ignored it and the tomatoes were fine (and plentiful) but I thought I should make an attempt to working out what is actually causing it!

Thanks!
Title: Re: Yellow patches on Tomato leaves?
Post by: Fork on July 18, 2007, 22:47:49: Probably short of some trace element like magnesium.
Title: Re: Yellow patches on Tomato leaves?
Post by: Chris Graham on July 19, 2007, 08:38:35: Yeh you probably need to give them some magnesium.

I had too and just sprinkled some on the soil (in pots) and watered in. Seems to have done the trick.

Tip - Boots the chemist has Epsom Salts (Magnesium) for £1.50 and you get quite a lot.
Title: Re: Yellow patches on Tomato leaves?
Post by: laurieuk on July 26, 2007, 12:51:07: My tomatoes have yellow patches on the leaves - any idea what it is?

I feed them once a week so assumed they weren't lacking in anything but something is wrong. I've had this before and ignored it and the tomatoes were fine (and plentiful) but I thought I should make an attempt to working out what is actually causing it!
Quote from: Smileyk on July 18, 2007, 22:34:54

Thanks!

If it is just the lower/older leaves that are going yellow I would not worry.Leaves go yellow once they have served their purpose and younger ones are taking over,some people remove these older leaves but if you let too much sun in it can harden the skins. A lack of magnesium usually shows as yellow areas between the veins rather than all over the leaf.
Title: Re: Yellow patches on Tomato leaves?
Post by: tim on July 26, 2007, 13:07:02: Smiley - does your feed have Magnesium in it - like most Tomato feeds?

(Another post for DISORDERS??)
Title: Re: Yellow patches on Tomato leaves?
Post by: Smileyk on July 26, 2007, 19:07:03: Just checked and the tomato feed does have magnesium in it. The yellow starts off like spots and then spreads out. It's not on the very top leaves but it is on leaves from about 3/4 down.

Should I take a pic?
Title: Re: Yellow patches on Tomato leaves?
Post by: valmarg on July 27, 2007, 15:42:22: Smileyk, you probably need to feed more often than once a week.

valmarg
Title: Re: Yellow patches on Tomato leaves?
Post by: cleo on July 27, 2007, 17:24:30: I could be missing something but if they are going yellow towards the bottom of the plant I wouldn`t worry
Title: Re: Yellow patches on Tomato leaves?
Post by: tim on July 28, 2007, 05:55:50: Spots don't sound like Mg deficiency?
Title: Re: Yellow patches on Tomato leaves?
Post by: laurieuk on July 28, 2007, 14:59:43: It really does sound like age, mine are the same and I would not worry.

Quote from: Smileyk on July 26, 2007, 19:07:03
Just checked and the tomato feed does have magnesium in it. The yellow starts off like spots and then spreads out. It's not on the very top leaves but it is on leaves from about 3/4 down.

Should I take a pic?
Title: Re: Yellow patches on Tomato leaves?
Post by: davyw1 on July 28, 2007, 15:10:54: The main three dissorders for yellow spots on Tom,s are
Gray Leaf Spot Spots with a yellow halo

Powdery Mildew

Spotted wilt
Title: Re: Yellow patches on Tomato leaves?
Post by: petengade on July 28, 2007, 15:44:06: Mine are the same, could it possibly be the beginning of tomato mosaic virus?
Title: Re: Yellow patches on Tomato leaves?
Post by: davyw1 on July 28, 2007, 17:46:41: Add this to your favourites/Bookmarks.

http://aggie-horticulture.tamu.edu/tomatoproblemsolver/leaves/index.html
Title: Re: Yellow patches on Tomato leaves?
Post by: Smileyk on July 30, 2007, 19:16:27: Great site that thanks!

Could be leaf mold.......
Title: Re: Yellow patches on Tomato leaves?
Post by: laurieuk on August 07, 2007, 21:17:56: It is like reading a medical book,it gives you a lot of things to worry over.