White Spots on Tomatoes could be Cotton Spot

There are many plant conditions that are caused by fungus. One such annoying condition is known as cotton spot. This fungal infection is caused by fungi proliferation as a result of warm, wet conditions during the early fruit production cycle of many plants.
When the soil is heavy or doesn't drain well for any reason, fungi spores can rapidly grow and spread throughout stagnant areas allowing fungus to grow in, on and around our plants.
Cotton spot appears mostly on cucurbits and tomatoes, and is particularly noticeable on the tomato fruits. It appears as yellow spots under the skin. Once peeled, the spots are white - hence the name. Sometimes the cotton spot will peel away with the skin, while other times it is found that the infection has grown into the meat of the fruit. 
cotton spot on interior of skin cotton spot in tomato meat cotton spot infection in tomato
   Cotton Spot Infection        Fungus on Interior of Skin      Fungus Infection in Meat     Cotton Spot Tomato Infection
There are several ways in which a fungus may affect a plant: root damage, foliage damage, and fruit damage. Knowing that fungi like warm, wet conditions to grow in gives us a starting point at which to begin to fight fungi before they become an issue in our gardens.
Improved drainage can often be achieved by adding either soil, sand or both. In addition, calcium can be added to the soil for both drainage and nutritient fortification. Natural soil treatment and amendment products can also be used to help prevent fungal infections such as cotton spot from beginning in the first place.
Garden Vigor offers products that help to fight fungus proliferation. Garden Vigor's VermActant supplies mycorrhizae to stave off the bad guy fungus in your soil. And Emerald Mist has micronutrients that enable healthy plants to better fend off fung.
For more information on plant and soil interactions or to ask specific questions, Contact Us.