What is going on with my tomato plants
Recently, my tomato plant's leaves started to turn brown and die. The main stalks are fine and it continues to produce and ripen fruit. However, with the lack of exterior branches, the tomatoes are sun-scorching and dying. The plants are about 4 months old and have had fruit for about a month. This started in one corner of my raised beds and has spread through the front line of the garden. It has affected about 5 plants so far.
Your tomatoes look like they were subject to a type of environmental issue as well as a fungal leaf spot. the leaves look like they may have been sprayed with a pesticide or possible fertilizer burn. The area looks hot and dry, crowded, with poor air circulation. Tomatoes need 4-6 sq ft of growing area and will be more productive with 8-10 hours of sunlight. Provide consistent moisture and mulch with an organic mulch to keep weeds down. See our tomato profile http://extension.umd.edu/growit/vegetable-profiles-tomatoes
Tomatoes are also susceptible to several leaf spot diseases. Two common foliar diseases are early blight and septoria but it does not matter which disease it is because the management is the same. Select disease resistant varieties, remove the lower leaves to slow the upward spread of the disease, keep plants well mulched to minimize soil splashing, water at the base of the plants, provide adequate spacing, and spray with an organic fungicide (fixed copper) early in the season to lessen the spread of the disease. Fungicide treatments can help to protect new or un-infected foliage, they are not curatives. It is too late to spray. Remove infected plant material at the end of the season. See our website for more information and photos on early blight http://extension.umd.edu/growit/early-blight-vegetables and septoria http://extension.umd.edu/growit/septoria-leaf-spot-vegetables