Leaves are turning yellow like this

Hi Suresh Marpuri. Compare symptoms with Magnesium Deficiency, Early Blight and late-blight/">Tomato Late Blight by clicking on green link for checking symptoms and taking control measures from Plantix library. Also need to apply good amount of Farm Yard manure or Vermicompost along with recommended dosage of fertilizers to get good growth of your Tomato plants. You can also use fertilizer calculater available here on home page of Plantix to get good growth and yield crop. You can also create a "Cultivation Tips" for Tomato in Plantix. It provides you information on how to optimize your crop production.