There is a disorder called yellow shoulders. The lower 1/2 or 2/3 will ripen but the top will not.If you leave the fruit on the vine waiting for it to turn red completly in can rot and fall off.

Hi temps can cause it as well as nutrient diffencey

Good Luck

Hmm ok I think I know why this is happening then. I looked up yellow shoulders on a search and found that like you said, it is mostly caused by high temps. So that's when I realized it's my fault.

You see, every year I have problems with chipmunks and/or birds taking large chunks out of my tomatoes just before they fully ripen. And the beginning of this year was no different. So I bought several yards of this wedding veil material- basically a very fine fabric mesh- and cut it into approx. 12" squares. I wrapped up tomatoes that were just starting to ripen with this material, and I figured since it is a mesh air can pass through it that there would be no problems. But I guess that was a wrong assumption.

Damn it, this mesh was working so great too! Every tomato I harvested was perfect- no holes in it or chunks gouged out... well except for the yellow shoulders.

I don't think the mesh fabric protection did it. Some kinds of tomatoes are more susceptible than others.

Beyond that, you might rig temporary protection above the plants during a hot spell. I use old window screens to cast a small amount of shade, but still allow plenty of light to get through.

I don't think the mesh did it either. I think you have the same thing I have bad on my Early Cascade - sublethal sunscald. I used to think you only get the sunscald on fruits in direct sun but with high temperatures too it affected foliage-covered fruit too. I think saturated soil may have contributed too at the time (steam heat?). My EC was in a cage on the south border so it was really exposed and is hit hard.

The only others to have sunscald are my 5 Sophies Choice that I didn't cage and lost a lot of leaves to early blight when I didn't spray soon enough in June - just before a week of temps around 90. Next year EVERYTHING gets caged, even small determinates.

I don't know about "yellow shoulders," but it sounds to me like you may have a cell tower near your garden, and those pesky, little, grey UFO guys who hide in microwaves are coming out at night and pulling the ripening tomatoes off your plant.

I think you guys who are doubting the mesh is having this effect are right!

I now realize that many of my Pruden's Purple tomatoes also have this yellow shoulders problem, and I never applied the mesh to them (for some reason the birds or whatever never seemed to go after them).

And the weather has been much more mild since I last posted here and so far no more problems with the yellow shoulders.

It's gotta be just simply too much heat during those weeks.

Thanks again !

What is sublethal sunscald? My tomatoes are developing brown areas on them that are quite nasty. Is this what it is? I've been very bad about watering properly and it has been very hot here so perhaps this is what it is?

My prudens purples did this too. Only about half of each tomato was edible, the top was hard and yellow. We had blistering heat here too this summer, I guess that did it.

I just logged on to ask this same question, and I saw that it had already been posted. We've had an unusually warm summer here in the "thumb" of Michigan, and some of my tomatoes have yellow or orange shoulders as well. I wondered if it was a nutrient deficiency, but the heat makes more sense since I have been really good about fertilizing this year. Thanks for the info!