Q: My potatoes have cracks in them. What causes this and how can I correct it?
A: The good news is the cracks are not caused by an insect or disease but by physical conditions in the soil and climate. The growth of the potato has alternating times of good nutrition and water followed by drought and temperature changes or such environmental conditions. Some potato varieties are more susceptible than others. For instance, ‘Atlantic’, used for making potato chips and ‘Red Lasoda’ for cooking often produce cracked tubers. ‘La Chipper’ and ‘Harley Blackwell’ are not as susceptible but they have been known to produce cracks during hot, wet years.
So what can you do? There are a few things to reduce the potential of cracked potatoes. The most important thing is to keep soil moisture consistent. Not too wet, but not too dry. Having said that – not too much can be done about excessive rain like a tropical storm but be sure irrigation is not the culprit. However, when the tubers are growing quickly (usually later in the season), they will need more water to stay healthy. Space plants in even rows and equal distances from each other. Overcrowding potatoes is not a good practice for strong plant and tuber growth. Be sure fertilizers are applied evenly as well. Attached is a publication from the University of Florida on this cracking problem. http://edis.ifas.ufl.edu/pdffiles/HS/HS18200.pdf