Suddenly Yellow Leaves

[AlittleSalt]

Sometimes, while growing tomato plants, the leaf section/s will suddenly turn yellow. We looked at this plant yesterday evening about 13 hours ago. It looked green. I noted that I need to remove some new lower growth, but otherwise it looks like a healthy 5' tall tomato plant that is growing like a weed.

It is a Porter tomato plant growing from seed that I saved myself. It's parent was grown by seed that I saved the year before. I sprayed Daconil on it a few days ago. All 9 of the plants in the last picture are Porter plants. I named the raised bed, "The Porter Bed". We plan to grow only Porter there year-after-year. They are really good looking plants that produce a lot of cherry tomatoes.

I woke up right at sunrise, opened the curtains, and there it is - yellow leaf sections. (Pictures 1 and 2) It happens every year, and I've always shrugged it off as - stuff happens. I always remove the yellowing leaf section/s, but it still has me wondering why this happens? Why do they suddenly turn yellow?

[MikeInCypress]

As we age our hair turns gray. As tomato plants get older leaves turn yellow.

MikeInCypress

[Worth1]

Originally Posted by MikeInCypress

As we age our hair turns gray. As tomato plants get older leaves turn yellow.

MikeInCypress

Works for me.

Worth

[AlittleSalt]

Hmm, aging and stuff happens ... Works for me too

[hornstrider]

I'm picking yellow leaves from the bottom every day. It seems the more fruit the plant produces the more yellow leaves I have to pick. I guess the plant gets tired.

[Elliot]

could be a fungus or other disease. Do you have horticultural experts you can take a sample to?

[zipcode]

That doesn't really look like normal aging. But can't say what it is either. Sudden lack of nitrogen maybe?

[Gardeneer]

Originally Posted by zipcode

That doesn't really look like normal aging. But can't say what it is either. Sudden lack of nitrogen maybe?

Yellow leaf, that much up high, does not look normal aging at this point in season. A weak plant/root system tend to abort older leaves early, to prioritize its resources.

[b54red]

It could also be the early signs of fusarium wilt especially if the yellowing first takes place mainly up one stem. Since my soil is riddles with all three races of fusarium that is always my first instinct when I see yellowing beyond normal aging. Since I started grafting using rootstock resistant to all three races of fusarium it is rarely a problem except on volunteers that I sometimes allow to grow. You can check for fusarium by cutting one of the stalks that is showing yellowing and check for the tell tale signs of yellowing or browning inside the stem.

Bill

[AlittleSalt]

Bill, you are probably right. I noticed there are a few more on the same plant today.

[oakley]

I don't worry much with a few lower yellowing leaves, even if sudden like an overnight.
Especially if on a full grown healthy looking plant setting bloom and fruit.

Usually weather stress, too much water or too little reaching the root mass. I usually start a regular feeding of fish/seaweed fert when i start seeing blossoms for a nitrogen kick....instead of my stingy weaker feeding.

Too much rain i have some rubber matting 2ft squares i can slip over like a collar.
Too little rain and hot weather, a real good deep slow soak with some fish fert, rather than multiple short waterings. Lots of mulch.

I always think of those as the plant is self-pruning since the lower few leaves are not really needed. But it is most likely one of the above.

Diseases/critters usually show much more leaf stress. specks, browning, rings, holes, etc.

[AlittleSalt]

It has been very humid for a week or longer. We have the AC on not because it's hot but to make it less humid inside. The dew point is near the nightly low temperatures leaving dew on the plants for half the day.

[Starlight]

Have you tried giving them some Epsom Salt. Helps alot sometimes if it is a nutrient deficiency. You might try on a couple of plants and see if it helps at all. If it doesn't I'd go with what has been posted already.

[AlittleSalt]

I haven't tried it yet Star. It is only that one plant out of 9 plants in that raised bed. I'll give it a try.

I forgot to add in post 12 - notice how the yellow area is on one side and not the other.

Bill, I just cut off a leaf section - the liquid is clear. I even mashed part of the stem to get more juice out of it and the same results - clear.

[AlittleSalt]

I cut/split the branch with a razor blade. This is what it looks like inside