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Boron Deficiency in Corn

Boron is a key element in plant nutrition. University researchers have found yield increases ranging from 9 to 37 bushels of corn per acre where boron was added. Corn requires high levels of all nutrients to ensure maximum economic yields.

Boron is necessary for:

  • Stimulation of root and shoot development
  • Tassel and silk formation
  • Movement of sugars from leaves to ears
  • Pollen germination
  • Pollen tube growth and seed formation
  • Better water use efficiency and drought tolerance

Irregular distribution of kernels and a general reduction in growth are the first signs of boron deficiency. Severe boron deficiency results in short bent cobs of corn with under-developed tips and very poor kernel development. Yellow or white spots develop between the veins on young leaves, and the spots often coalesce forming streaks. These streaks, which may be waxy and raised from the leaf surface, do not normally develop on fully grown leaves. The leaf tips may be curled. There is also a shortening of the internodes and often the young leaves fail to open. There are indications that high-lysine corn is more susceptible than normal corn to boron deficiency.

How much boron is enough?

  • Corn removes significant amounts of boron from the soil each year. In high yield situations, boron fertilization becomes critically important. Most universities recommend boron at planting, in sidedressing, or fertigated for irrigated corn.
  • Rates of boron fertilization should be based on yield goals along with soil tests and/or plant analyses. The chart above gives general application rate guidelines.

Timing your boron application

  • Boron may be applied in dry bulk blended fertilizer, broadcast before planting, using Granubor® 2.
  • Boron in liquid suspensions may be applied broadcast before planting, banded at planting, or sidedressed, using Fertibor® in suspensions.
  • Boron in liquid fertilizers may be broadcast before planting, banded at planting, sidedressed, or fertigated, using Solubor®.
  • Boron for high-yield, irrigated corn may be applied most conveniently through the irrigation system as Solubor® 4-6 weeks after emergence in two applications up to one pound each.
  • Never apply boron in direct contact with the seed.

Soil Application (Suggested rates of application)

  Granubor 2 Fertibor
LBS./ACRE 4-9 4-9
KG/HA 4.50 - 10.13 4.50 - 10.13

Foliar Application (Suggested rates of application)

KG/HA 2.25 - 4.5

Crop study: Corn

United States 2012

Discover the key findings in a U.S. Borax study (partnering with the University of Missouri) on the impact of borate soil-type fertilizers on corn crops. Watch video

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

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