Our Insights | Crop Protection
June 04, 2020

Fighting Calcium Disorders with Foliar Applications

As the weather continues to warm up during the transition from spring to summer, calcium deficiencies can produce a variety of disorders in vegetables and tree fruit. These include tipburn in lettuce, blackheart in celery, internal brown spot in potatoes, blossom end rot in tomatoes, corky spot in pears, and bitter pit in apples. All of these disorders occur in rapidly expanding tissue that can have limited supply of calcium from the soil.

Tipburn in lettuce

Source: University of California Agriculture and Natural Resources

Calcium availability is closely linked to water uptake from the soil.  Low soil moisture and/or high heat can reduce uptake of calcium.  Standard practices for mitigating calcium deficiencies include good irrigation management and amending the soil with calcium sources like gypsum.  However, fruit and young  leaves naturally receive a lower supply of calcium because they have lower transpiration rates than mature leaves and do not pull as much calcium up from the soil.  Calcium is also highly immobile within plants, so it cannot easily be remobilized from older leaves

Bitter pit in apples

Source: Washington State University Tree Fruit Research and Extension Center

Calcium plays a critical structural role in the formation and stability of both cell walls and cell membranes. Calcium related disorders occur when a localized lack of calcium leads to poor cell wall and membrane function and eventually causes cell death in the area. Foliar calcium applications that are directly absorbed by the expanding tissue, helps prevent these types of localized disorders from occurring.

Blossom end rot in tomatoes

Source: University of California Agriculture and Natural Resources

Foliar calcium also help with fruit quality of other crops like berries, melons, and stone fruit. The resulting improved cell wall structure enhances firmness of the fruit, and reduces post-harvest diseases such as Botrytis cinerea in berries.

Brandt has several foliar calcium formulations that can help reduce calcium disorders and enhance post-harvest fruit quality. Our BRANDT® Manni-Plex® foliar nutrition line includes several products, including Foli-Cal, Manni-Plex Cal Zn, Manni-Plex Cal Mag, and Manni-Plex Cal-B all utilize sugar alcohol complexes. For sustainable products, our BRANDT® Organiplex™ product line includes BRANDT Organiplex 8% Ca that utilizes an amino acid complex and is approved for organic use.