Expert Help Needed - pics included

[HoustonHeat]

I am new to gardening. I had very healthy green plants but in past few weeks they all are turning lighter colors but one in particular is turning purplish. Is this just the heat or is this curly top disease or just a NPK deficiency? I heard low P could cause purple color?

[zipcode]

It does look like very low nutrients, especially N.
Did you fertilize with anything? When fruit start growing, the plant needs lots more nutrients.

[gdaddybill]

It looks like fairly extreme nutrient deficiency. Low phosphorous can cause the purplish cast but I think the plants need a good balanced fertilizer. Try an organic like 4-4-3 + CA on the soil and foliar applications with a hose-on sprayer. The sprayer type that you put in the container straight and it blends from the saturated solution at the top(no rubber hose in the container) are relatively safe to use. There shouldn't be any foliage burn if the soil is watered first.

[RayR]

Nutrient deficiency, I don't think so.
You better check the underside of the leaves for mites.

[WhippoorwillG]

I will stick with nutrient deficiency and heat. If you are growing in containers, I will double down on that assessment.

[jillian]

Yes, looks like they are starving for nutrients.

[HoustonHeat]

Thanks all the responses. I am going to fertilize well and maybe add some black cow manure compost a neighbor recommended. These are not in pots but rather a 1ft x 8ft garden box that is 6 inches in the ground. It's natural earth bottom with some potting mix mixed into soil. The wood frame is just to keep the weed eater at bay.

[HoustonHeat]

I have looked for insects but cannot locate any. I will google notes pictures and look again. I also will plan a neem oil + seaweed foliage early in morning..

[oakley]

Oh, sad. Looks like you are growing in raised beds? Being a new gardener, what is your
soil like or what was used to get going this year. You have mulched so that's a good
thing.

Sometimes too much and too little looks alike. Difficult to get to a nice well balanced
level of care, being water or ferts/food.

Looks to me like over-fertilizing. And out of balance what was used. If they were very
healthy looking to grow all that foliage, your soil if a bagged variety, may have had all
you needed for a while. If you have not fed at all since planting, ignore me, lol.
(but some bagged soils do have a slow release fert)

*cute blue weim ...i know that look so well

(we were posting at the same time...)

[ginger2778]

Originally Posted by RayR

Nutrient deficiency, I don't think so.
You better check the underside of the leaves for mites.

Exactly this! I agree 100%. Mites mimic nutrient deficiencies, especially iron, and Phosphorous.

[ginger2778]

Originally Posted by HoustonHeat

I have looked for insects but cannot locate any. I will google notes pictures and look again. I also will plan a neem oil + seaweed foliage early in morning..

I can see some right in the picture of the enlarged purple leaf. You need at least 10 to 14X magnification to see mites fairly well, they don't show to the naked eye.

Pyrethrins or Permethrin is a better treatment for mites.

[RayR]

Originally Posted by HoustonHeat

I have looked for insects but cannot locate any. I will google notes pictures and look again. I also will plan a neem oil + seaweed foliage early in morning..

Do you know you can't see mites with your naked eye? Either use a 10X or better magnifier or do the white paper test, put a white sheet of paper under the leaves and slap the leaf with your hand. If you see any tiny specks moving around, you have mites.

[HoustonHeat]

Well little doggy..... I did the paper test and while it did not reveal much I did see 2 specs moving around.. I assume where there is 2 there is 200?

[zipcode]

One can see adult mites easily with naked eye (I guess it depends on the eyes though). Young ones, well also with some difficulty, but you need to know exactly what you are looking for.
To have such bad deficiency in actual soil is really hard, not sure what to say, I'm fairly certain it's not the common two spotted mite though, at least not the main culprit.

What has happened between the point when the plants looked good till now?

[RayR]

Originally Posted by zipcode

One can see adult mites easily with naked eye (I guess it depends on the eyes though). Young ones, well also with some difficulty, but you need to know exactly what you are looking for.
To have such bad deficiency in actual soil is really hard, not sure what to say, I'm fairly certain it's not the common two spotted mite though, at least not the main culprit.

What has happened between the point when the plants looked good till now?

You must have super vision or some really big mites in Europe. The only type of mites I've had to deal with in the north are Two Spotted Spider Mites. In the Southern US they have an assortment of mites that feed on tomato plants, Two Spotted Spider Mites, Red Spider Mites, Broad Mites, Tomato Russet Mites and God knows what else.
What looks like a nutrient deficiency at the soil to some people here except Marsha and I. is a nutrient deficiency in a round about way if you consider that mites suck the life out of leaf cells and dead cells can't transport nutrients.