{Helianthus annuus}
Sunflower malformed flower development

Spotting a Boron Deficiency

Malformed sunflower development.

Sunflower malformed flower center development

Spotting a Boron Deficiency

Malformed flower center development.

Aborted flower head from insufficient boron.

Spotting a Boron Deficiency

Aborted and malformed sunflower head caused by boron deficiency.

Sunflower incomplete seed development

Spotting a Boron Deficiency

Incomplete seed development caused by boron decficiency.

Sunflower malformed head

Spotting a Boron Deficiency

Malformed head caused by boron deficiency.

Boron Deficiency in Sunflower

Boron deficiency symptoms first appear on the youngest leaves which become progressively smaller and malformed. The stem will be short due to lack of extension of the cells in the internode. Distortion of flower heads is commonly seen and seed set on the head is very uneven; sections of the head may show no seed set at all. This symptom is associated with the boron requirement of the pollen tube. When the deficiency is very severe, the growing point dies and no flowers will be formed.

Soil Application (Suggested rates of application)

  Granubor 2 Fertibor
LBS./ACRE 6-18 6-18
KG/HA 6.75 - 20.25 6.75 - 20.25

Foliar Application (Suggested rates of application)

LBS./ACRE 4-13
KG/HA 4.5 - 14.625

U.S. Borax, part of Rio Tinto, is a global leader in the supply and science of borates—naturally-occurring minerals containing boron and other elements. We are 1,000 people serving 500 customers with more than 1,700 delivery locations globally. We supply 30% of the world’s need for refined borates from our world-class mine in Boron, California, about 100 miles east of Los Angeles.  Learn more about Rio Tinto

Copyright © 2018 Rio Tinto. All Rights Reserved.