In my part of the world in the U.S., late blight kills a tomato plant within a week or so. There are brown spots on leaves and stems. There's not much you can do to halt the disease.

There are a couple different diseases in the U.S. commonly called early blight that are not related to late blight (or each other). I think they also are associated with a lot of leaf browning and death, and not limited to the tomatoes. You may have diseases we don't have, and vice versa. Do you have a service that tracks disease in your area? Local experts are the best source of advice.

Thanks for the response. I am actually from the US. U just happen to live part time in NZ, where I recently took up growing tomatoes for the first time. But from speaking with a lot of folks out here, it seems the diseases are basically the same. Blight being the big one, especially with all the humidity. We are pretty remote and there are no real experts I can go to around here.

My understanding is that late blight is pretty harsh, but early blight can be kept at bay with copper. So that's what I've been doing. All seemed okay until these bruises appeared on a couple of fruit. Is your opinion that if the leaves and stems are not showing signs then it's probably not blight?

I've been looking at some pictures of sunscald and it doesn't look too dissimilar from some of those, but I'm not really sure.

Anyone else have any specific ideas?

Thanks again.

There are a lot of folks on this forum who know more about tomato diseases than I do. A good source of information with photos to help you diagnose problems is Cornell University's Vegetable M.D. Online, which I link to below.

Here is a link that might be useful: Tomato Disease Identification Key

Microphobik, Late Blight always begins with lesions on the leaves. Later, they are visible on stems as well. If the plant doesn't die within the first 2-3 days, it's typically several days (or more) later before you will see spots on the fruit.

The spots on the leaves are fairly distinctive, so I'd try to determine whether you think that's the type of leaf lesions you have. Here is Cornell's page of Late Blight photos (scroll down). Note that none of these leaf lesions are small, round, dark spots.
http://www.longislandhort.cornell.edu/vegpath/photos/lateblight_tomato.htm

When I look at the photo of your fruit, I think the spot in the middle is probably sunscald (I almost never see sunscald here, so I'm not good at identifying it, but that spot certainly doesn't look like Late Blight). But to the left there might be a Late Blight lesion; I can't see enough of it to be certain. Generally newer Late Blight fruit lesions are roundish, mottled in color, and bumpy rather than smooth. (The Cornell photos of lesions on green fruit don't include any new lesions.)

The good news is that fruit on infected plants are edible. Some people eat fruit with lesions, but I haven't tried. You can save seeds from infected plants and the LB won't be transmitted to the next generation.

If you have had Late Blight spores in the area (they can blow in from miles away), they will continue to blow around and re-infect your plants. It's important to bag infected plant tissue and dispose of it off your property, as that reduces the number of spores.

This year I had LB (that's 3 of the 5 years I've grown tomatoes here). I spent a couple of months trimming the bad bits off what was initially about 30 plants. A lot of time and back pain. There were victories and defeats, but I got some fruit. That's better than some years....

If you're going to be growing tomatoes on that property in the future, it would be a good idea to ask your local agricultural agent whether you need to take precautions in order not to infect next year's plants. In the U.S., freezing winter weather takes care of that problem, but there may be other variables in NZ.

Disclaimer: I am not an expert, but I have seen a lot of Late Blight.

Thanks missingtheobvious, that was really helpful. After looking at more pictures and watching the plant for a few days I'm thinking that this may just be sun scald. Hoping anyway. Thanks again.

That is a picture of classic "SUNSCALD". It is caused by too much hot sun on one area of the fruit. Basically, it cooks that area. Let it go and when the fruit matures and is ready for harvest, simply cut that littl section out and eat the rest.

Ted

Thanks Ted, that makes me feel a lot better.