First of all, yellowing and brown spots on the leaves of tomato plants can be a sign of different types of diseases, such as early blight, late blight, or septoria leaf spot. These diseases are usually caused by fungi that thrive in warm, humid environments and can spread rapidly in crowded, humid conditions. Based on your description, your tomato plants may be experiencing some type of fungal disease. Brown spots on the leaves, along with the white residue you mentioned, are common signs of fungal infection. Additionally, the presence of fruit flies on plants could also indicate fungal growth, as fruit flies are attracted to the sweet odor produced by fungi. To address the problem, it is important to take some steps to prevent further spread of the disease. First, you should remove all infected leaves and dispose of them in the trash, rather than composting them. This will prevent the spores from spreading to other plants. You may also consider applying a fungicide spray to the remaining leaves, especially if you see new spots appearing. As for leaf yellowing, this could be due to a variety of factors, including nutrient deficiencies, overwatering, or pests. You mentioned that your soil was low in nitrogen and phosphate, so applying organic fertilizer was a good next step. However, it can take a while for the plants to recover, as the yellowing can be the result of previous stressors. As for fruit flies, you may want to try some natural remedies, such as using sticky traps or applying a dish soap and water solution to the floor. These methods can help reduce the number of flies without the use of harmful chemicals. Finally, since you mentioned that you are a novice tomato gardener, it's always a good idea to do some research and educate yourself on common problems tomato plants can face. I would recommend visiting a website like https://thegardenplants.com/pests-diseases/leaf-problems/, which from what I've seen has quite a bit of information on leaf problems on various types of plants, although I don't think there is an article on tomatoes many of the solutions for these problems are useful regardless of the plant in question. I hope this information is useful to you and good luck with your tomato plants!

How recently was this planted? Plants coming out of shaded positions at nurseries can burn during sunny weather later when placed in full sun. If they were kept in the shade long enough beforehand that leaves were formed in the shade, that are not adjusted to full sun.

regardless of where you live.. didnt fall start last week??? and it was recently transplanted ... and its a largish plant ... its stressed ... and finally.. its a deciduous tree ... the stresses are making it shut down a bit early ... i am presuming this is a eastern redbud.. Cercis canadensis ....of which i am familiar... if not.. then my answer might change .... i only mean to point out that your use of a common name can lead to confusion .... so use of the latin name would make it specific .... one of the reasons trees are planted dormant ... is that you dont have leaves to worry about on deciduous trees .... or they are dormant on evergreen plants .... either way.. you usually just dont have to look at something like this.. and then worry ... anyway.. just water deeply and properly with near drying before repeating ..... and see what happens .... see link on watering ... since it deciduous.. there is no use spraying anything on leaves that are going to fall off this time of year ... imo ... ken https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

I know you've been around the forums for a while, so I'm wondering if you've been monitoring soil moisture levels with a 'tell'? A tell is much more effective than a "moisture meter" or a digital device (a finger). The symptoms do look like there are issues in play which are related to an overly water-retentive soil and or a high level of salts in the soil. Please tell us how you decide when it's time to water, how you fertilize, what you use, and how often you apply the fertilizer. Does your pot have a drain hole? Do you have a set-up so that once water exits the drain hole, there is no possibility of the effluent finding a pathway back into the soil. What kind of temps, light levels, humidity, is the plant dealing with? Water uptake is an energy-driven process, and it takes oxygen in the root zone to burn the food to make the energy. An inadequate oxygen supply = limited root function = an inability to move water to the plants most distal parts (leaf tips/margins) = the manifestation of the symptoms depicted in your images. So, let's wait to see what you have to say, then see if we can determine what needs fixing, then develop a plan to get it fixed. Al