Looks like cold damage since the leaves look otherwise healthy and the damage is taking place between veins (and also not on a continuous leaf margin).

Plants usually outgrow and survive this just fine as long as a hard freeze or continuous cold period doesn't move in.

It's generally a good idea to wait until nights get into the 50s somewhat predictably (though a few trips into the 40s for a few hours won't hurt too bad) to plant out toms...and provide cover for low-40s or below.

It's also a good idea to harden off seedlings going from inside to outside to get them acclimated to wind/weather to form a bit more protection on the leaf surfaces. Early cold damage is a lot more common that late/established-plant cold damage.

Thank you! I thought I'd hardened them off enough, but evidently not. It's also been a pretty cool March and I haven't been covering at night...

Is your cottonseed meal sourced organically? Cotton is one of the most heavily sprayed crops, and the pesticides they use are not restricted to food grade chemicals.

So perhaps the tomatoes are being burned by residual pesticide from the cottonseed meal.

Second, google images of "tobacco mosaic virus." Are you a smoker?

Tobacco mosaic virus TMV hasn't been an issue in this country for over 30 years unless you are smoking imported Turkish cigarettes.

I agree with nc-crn - most likely they just weren't hardened off and/or protected sufficiently. Are they mulched already in that photo? Is your soil that warm already? If not I'd sure pull back the mulch.

Dave

its physical damage due to cold or wind. Nothing to worry about. The next leaves will be fine.