Studies on cracking in tomato fruits. I

Mechanism of fruit cracking

Abstract

This study was made to determine the factors closely associated with the tomato fruit cracking in the summers of 1957 and 1958.
1. Although tomato fruit absorbed 0.6 to 2.4 grams of water at immersion in water, cracking did not occur unless it had approached to the pink stage.
2. Removal of two-thirds of the leaves from the vine increased concentric crackings, but decreased radial and side crackings. Shading of fruits decreas-ed all types of crackings. The least cracking was found on the plants whose leaves were removed and whose fruits were covered with black paper bags.
3. Soil moisture also had a marked influence on the cracking of tomato fruits. By keeping plants at low soil moisture, severe of cracking was reduced, while enhanced at high soil moisture. The change from low to high soil moisture induced more cracks than that from medium to high soil moisture.
4. Among the factors concerning the cracking, elasticity of fruit skin, sugar content of fruits, and root pressure seemed to be most important.
5. Radial cracking was induced by internal ex-pansion pressure of fruit, and concentric one by water uptake through the corky spots on the fruit.