I have been asked several questions about tomato issues recently. One of the most common questions is the cracking or splitting of a perfectly good tomato on as it ripens on the vine.
This is caused by pressure inside the fruit that is more than the skin can handle. Cracks are usually on the upperpart of the fruit and can be concentric (in concentric circles around the stem) or radial (radiating from the stem). While this phenomenon is somewhat of a mystery, here is what I know about the growth of a tomato.
Tomatoes have a root system that is very dense and fibrous and is very good at taking up water.
Unfortunately, the root system can become unbalanced with the top of the plant, and that is where our troubles begin.
Early in the season it may be small in relation to the top growth resulting in blossom-end rot during hot dry weather.
Later it may be so efficient that it provides too much water when we get rain or irrigate heavily after a dry spell. This quick influx of water can cause the tomato fruit to crack.
Blossom end rot is when the flat, leathery area on the blossom end of the fruit - opposite the stem end. This condition is often first seen when the fruit is about half-grown and continues as it matures. This is not a disease but a non-parasitic disorder that is most common on tomatoes. Blossom-end rot is the result of a calcium deficiency in the blossom-end of the fruit. Calcium is required in relatively large amounts when fruit is growing rapidly.
If demand exceeds supply, deprived tissues break down leaving the characteristic leathery bottom. This may be the result of low calcium levels in the soil (rare in Kansas) but can also be caused by a sharp change from cool to hot weather, extreme soil moisture fluctuations, drought stress, root damage due to deep cultivation or waterlogged conditions, or excessive growth due to too much nitrogen fertilization.
So, while Mother Nature and is helping contribute to these issues, they are not detrimental to the plants.
For more information on tomato issues or other gardening questions, contact the Ford County Extension Office at 620-227-4542.