When we have the stretches of high temperatures that we see each summer, we can experience problems with vegetable fruit set and quality.  Tomatoes are one of the most common plants that I get questions about in the Extension Office.

Daytime temperatures over 90° F and night temperatures over 70° F reduce fruit set in tomatoes.  Flowers die and drop due to lack of pollination or the pollen being non-viable.  Once temperatures cool, fruit set will resume.

There are a couple of causes of white spots in the tomato fruit.  One is weather related and that is internal white tissue that is only noticeable when the fruit is cut.  The hard, white areas tend to be in the outer walls of the fruit, although it can also appear in the center of the fruit.  High temperatures during the ripening period seem to trigger the symptoms.  The darker red varieties are more resistant to this problem.

Another cause of white spots that are usually visible in the skin is damage from sucking insects – mostly stink bugs of some type.  When they insert their proboscis into the fruit to feed, they inject an enzyme to

help break the fruit down, so they can easily suck the juices out.  This enzyme causes the white spots.  In my garden my major pest is a type of stinkbug called the Eastern Leaf-footed Bug.  It gets its name from the “leaf-like” appendages on it rear legs.  Just like a stink bug this insect feeds on fruits, and in my garden it is the tomatoes that suffer damage.  You can handpick these pests and drop in soapy water or use an insecticidal soap.  One of my co-workers was so disgusted by them that she took her leaf blower to them and blew them away!

In both cases of white spots in the tomatoes, the fruit is still edible, just cut those spots out.