Growth Cracks

Disease Identification

Description

Growth cracks are an environmental disorder found on fruit that is approaching peak ripeness.  They occur on the ends of fruit nearest the stem and run either radially along the length of the fruit or circumferential.  Early on, these cracks are quite shallow in depth but if conditions are right, the cracks will continue to widen and deepen.  Infection of the fruit often follows.

  • Leaves: Not affected
  • Stems: Not affected
  • Fruit: Cracks will appear on the fruit often near the stem.

Images

Tomatoes

Growth cracks on tomatoes often originate at the stem and continue down the fruit. They may also be seen spiraling around the fruit.

Affected Plants

Disease Control

Life Cycle

Growth cracking of fruit is primarily caused by uneven applications of water.  As fruit begins to mature, the outer skin becomes tougher and less flexible.  If heavy rain or excessive watering occurs, the roots can take up large quantities of water, pushing it into the fruit and causing it’s brittle skin to split.  The plant often does a good job of sealing these cuts leaving little more than a scar where the split occurred.  However, if rainfall and/or watering continues, the split will increase further.

Apart from being unsightly, growth cracking usually doesn’t affect the fruit.  However, if conditions do not improve or water is allowed to sit on the fruit, the cracks can introduce disease resulting in ruined produce.  If you notice cracks appearing and continued rain is in the forecast, it is advisable to pick the fruit early as the condition will only worsen.

Management

  1. Long, Deep Watering:  During the summer, supplemental watering may be necessary to maintain adequate fruit production.  If this is the case, it is critical that you water very slowly over a period of an hour or two in order to ensure the water soaks deeply into the soil.  longer watering sessions encourage plant roots to grow deeper and rely less on water near the surface.  Often, it is a rapid influx of this surface water that causes the fruit to split.
  2. Picking Produce Early: Because the skin of fruit becomes tougher  as it gets closer to peak ripeness, harvesting produce slightly early and allowing them to finish ripening off the vine may reduce if not eliminate instances of cracking.  The only downside to this method is the fruit is often less flavorful than if it was left on the vine to fully mature.
  3. Resistant Varieties:  Some varieties have been shown to resist cracking and may be worth pursuing if cracking remains an issue.  The downside is these varieties generally produce fruit with thicker and tougher skins which may be less desirable to consume.  It is a balance between resistance to cracking and enjoyment of eating.