Leaf roll? Bacterial Canker?
Hello, I was hoping some one might be able to help me identify what is bothering my tomatoes. All of my plants have leaves curling upwards over the entire plant. All leaves are still green though on just one branch on one plant i started to see some brown spots on the edge (photo attached). I cut off the affected branch and split the stem, but tissue looks green and healthy inside. I wanted to identify to know if I should destroy to prevent spread of something, or if it's just because it has been hot this June/July in the 90s already? Plants are on drip and not overhead watered. I have several varieties all affected including an early girl, green zebra, white tomasol, napa chardonnay. The striped Roman seems hit the hardest. The only one that seems unaffected is a spoons.
Weld County Colorado
Diagnosing tomato problems can be difficult, especially in the early stages.
According to the Colorado Master Gardener Handbook, “The Science of Gardening,” VFN varieties are recommended. V stands for resistance to Verticillium wilt, F for Fusarium wilt ((both are common soil borne fungal diseases) and N for resistance to nematodes (not common in in Colorado). Hybrid tomatoes usually have resistance, but many gardeners prefer to trade off the superior flavor of heirloom varieties for disease resistance.
Here is some research-based information from Colorado State University Extension Service: http://extension.colostate.edu/topic-areas/yard-garden/recognizing-tomato-problems-2-949/
Here are pictures of plants you may want to look at: http://vegetablemdonline.ppath.cornell.edu/DiagnosticKeys/TomLeaf/TomLeafKey.html#fusarium
As you suspect, hot weather may be stressing out your plants, allowing them to become more susceptible to disease. Garden sanitation, plant spacing and trellises help.
More questions: Were herbicides applied to your tomatoes, or near your tomatoes? Perhaps herbicide drift might cause the leaf curling? Damage may look very similar to Cucumber Mosaic Virus. Tobacco mosaic virus is another possibility.
Another very common problem you may consider is tomato early blight, resulting from a fungus, Alternaria solni, which causes leaf spots. Treatment? Remove lower leaves, focusing on leaves with spots. Removing just the lower yellow leaves will not be adequate. Wash hands with soap and water immediately after touching diseased leaves to avoid spreading disease to other plants. Mulching helps. Keeping nitrogen levels up in mid-summer is an early means of blight control and will significantly improve yields. However, crop rotation, allowing no tomatoes, peppers, potatoes, eggplants, vine crops, strawberries or raspberries for at least four years, is difficult in the home garden. See: www.ext.colostate.edu/mg/Gardennotes/718.pdf