Hello Daniel,

It is interesting that the same thing happened last year after pruning. The leaf tissue appears to be desiccated. Desiccation can occur from chemicals, or wind or sun damage. It could also be related to insufficient or incomplete watering.

Do you clean your pruners before you prune? What do you use? Typical sanitizing cleaners are 10% bleach solution or rubbing alcohol. These typically do not affect the plant tissue. As part of pruning, do you fertilize or apply herbicides at the same time? Fertilizers are compounds that can desiccate the plant tissue. Errant herbicide can burn the tissue as well.

The area that shows the bleaching – was that previously protected from the sun until other foliage was removed by pruning? If that leaf surface was protected, then all of a sudden was in strong sunlight, it could become sun scalded. Wind and sun can desiccate leaf tissue rapidly.

Are these tomatoes in containers? Containers with good drainage can make it difficult to maintain good and consistent soil moisture. Too little irrigation could lead to stunted, dehydrated new growth.

Beyond the bleached tissue, there does appear to be some fungal disease on leaves.

If this condition results in severe damage to your tomato plants, you may want to send a tissue sample to the MSU Diagnostic Labs to get a definite assessment of the cause. Take a tissue sample of any discolored foliage and send it to the MSU Diagnostic Labs for identification. The following website describes the services and the fee structure for analysis performed by the Diagnostic Lab.: https://www.canr.msu.edu/pestid/

This website provides directions and tips for taking a good sample: https://www.canr.msu.edu/pestid/submit-samples/

Thank you very much. 

Sent from my iPhone

On Jul 14, 2024, at 9:15 PM, Ask Extension <<personal data hidden>> wrote:



Hi Daniel,

What I see in the photos you attached is not consistent with Yellow Tomato Leaf Curl Virus.  That doesn't mean it is not a viral pathogen.  

Do you buy plants from the same grower each year?  Is the yellowing and curling fatal or does the plant eventually return to normal growth?  If the yellowing and stunted growth ends up being fatal, you should consider sending a sample to the lab for analysis, so you know positively what is affecting your plants.

Hello Daniel,

Forgive me if this is information you already understand, but I want to make sure you are pruning your tomatoes correctly and not cutting off the "leader".

https://hort.extension.wisc.edu/articles/tomato-pruning/