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tomato leaves turn yellow and purple

Posted by karthikas none (My Page) on
Sat, Jun 23, 12 at 5:35

Dear all,
I am an amateur gardener. I have some pots in the balcony and I grow flowers and herbs like mint. I do not have problem with them. A month back, I planted some tomato seeds (just the seeds from store-bought tomatoes) in a pot and used the normal soil got from a supermarket. It says that nutrients in it are sufficient for 4-6 weeks. But, the supermarket lady warned me that it will not be sufficient for plants yielding vegetables and fruits and said I need to top up with fertilisers later.

The tomatoes plants grew; there were many plants in the same pot and all was well till a couple of days back. The leaves at the bottom of the plants started turning yellow. Very soon, the whole plant had a purplish hue. And the underneath of the leaves (veins) turned dark purple. A couple of leaves have shrivelled up almost died. In some places, I can see yellow and purple patches. I googled for info, but I am unable to decide whether it is a phosphorous (or some other) deficiency or a disease. Could anyone here kindly help me?

The temperature here varies between 10 and 25 deg C now.
Thanks in advance for all your replies!

Follow-Up Postings:

RE: tomato leaves turn yellow and purple

My recollection is that phosphorous sounds right for purple. And perhaps nitrogen for yellow. Determinate tomatoes get to be big plants. Indeterminate tomatoes make determinate tomatoes look small (7 to 10 feet). The "pot in a pot" looks small for a big plant. I'm thinking you need to fertilize.

Add some NPK, add some mirco-nutrients if possible, fish/kelp fertilizer is good. Micro-organisms in the soil is good.

Compose is good. Tomatoes can be buried deep, the underground stem grows roots. So at a minimum you can toss a bunch on top next time before you water. If you are going to transplant, mix it in the hole.

I'm trying a dose of old horse dodo this year for each plant. Plants are big, have flowers. It may nave been too hot to set fruit in the past week.

RE: tomato leaves turn yellow and purple

Clay is correct about the purple being phosphorous deficiency.

The other glaring problem is if you had many plants in a pot that size there would be too much competition. Realistically, 10 gal pot is the minimum size for 1 indeterminate plant (I would recommend no smaller than 25 gal. but many people claim success at 10 gal.) Fertilize and cull the weaker plants leaving the healthiest one.

RE: tomato leaves turn yellow and purple

They're starving.

Further, way too many in one pot.

Sacrifice the least vigorous by snipping them off so that you can retain the root system of the one plant in good condition.

RE: tomato leaves turn yellow and purple

Thanks to all of you for your suggestions. I am following your suggestions - applying fertiliser, repotting and getting rid of the weak plants. I will let you know if they survive... Hope they would. Thanks to all of you for your time!

RE: tomato leaves turn yellow and purple

Dear members,
I followed your suggestion of repotting and adding NPK fertiliser and it worked. The plants have been growing well. I fertilise them when they show signs of purpling/yellowing leaves at the bottom (which is once in 2 weeks). They flowered and are now bearing fruit!

Yesterday, I noticed a couple of problems; a few the leaves of one plant in the middle region of the plant have oval brown spots, from the tip of the leaf to about 60% inward (plant 1).

More leaves in 2-3 other plants have yellow patches in them with small brown spots (plant 2). This looks different from picture 1 to me.

The third problem is the presence of tiny winged insects on many leaves (in the picture, I have circled the insect in red). These appear on all plants. They look like flies, but from googling, I guess they are aphids. I am unable to get a good picture of these creatures. There are black spots (eggs?) on the leaves, but I am not sure if they are some fungus or the eggs...

I applied fertiliser 2 days back. It has been exceptionally hot here (35 deg C) this week. I noticed that the soil turned dry 2 days back. I water them once daily in the morning usually.

The stems, flowers and fruits look good, till now. The young leaves look fine.

What is the problem with the leaves? Is it a disease of another manifestation of nutrient deficiency? Will cutting off the damaged leaves and those with the insects solve my problem? I am going on a short vacation (5 days) and am worried the plants will be in a worse shape when I return. Thanks again for your precious advice!


RE: tomato leaves turn yellow and purple

Plant 1

RE: tomato leaves turn yellow and purple

Stiull healthy fruits of plant 1.

RE: tomato leaves turn yellow and purple

Finally, plant 2. Sorry for so many posts.

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