Does anyone have an idea what is killing our tomato plants? This is our fifth season, and it's the first time we see these symptoms. We grow them in the soil (some in raised beds, others on the ground level, and a few in big pots). Probably half of them have this issue (and they are in different locations of the garden). We used potting soil, compost (home made), and potato plant food. Tomato plants came potted from local nurseries (Sacramento, CA). Thank you!