I bought some yellow fleshed beets at a nice farm stand in the fall. They looked good to me on the outside. Once I cooked and cut them open, though, this very dark (at least after cooking!) hollow center was revealed. It was present in all of the several beets in the bunch. The good news is that it could just be cut out and the beets were still delicious.

Beet.hollowheartJAllen

Photo by Joan Allen, UConn

But what might have caused this symptom? There are a couple of possibilities and the cause was not determined. Those that come to mind include inconsistent water supply and boron deficiency. Sometimes when a crop is growing slowly due to limited rain or irrigation followed by a sudden plentiful supply of water, the growth rate can suddenly increase and result in this ‘hollow heart’ symptom or disorder. I know this happens in potato but I’m not sure whether it’s likely in beet. There’s a major difference between the two….potatoes, while they grow underground, are actually stem tissue. You can tell because they have buds, what we commonly call the eyes. Beets, on the other hand, are root tissue.

Boron is a micronutrient for plants and a deficiency has been associated with hollow sections of stems or roots in some crops. Beets are listed among those crops that have a high boron requirement relative to others. Factors that can influence the availability of boron to plants include soil pH, sandiness of the soil, and soil organic matter content. A consistent and adequate amount of water uptake by the plant is necessary to take in boron from the soil. This is influenced by transpiration, the loss of water from the leaves. Conditions that reduce transpiration, such as humid, cloudy or cool weather, can be related to deficiency. High pH (alkaline) reduces availability of boron. Sandy soils or those with low organic matter content are more prone to boron deficiency.

How could the cause in this case have been figured out? Soil and tissue analysis can be used to measure nutrient availability and content in the plant parts. Soil tests can check not only nutrient content but also organic matter levels. UConn’s soil and tissue analysis lab info can be found at www.soiltest.uconn.edu. If a boron deficiency is confirmed, soil can be amended using borax, boric acid or Solubor. Different vegetables have different boron requirements. Lists of those most likely to develop a deficiency can be found in this fact sheet from UMass.

J. Allen