Boron and Molybdenum: Keys to Good Flowering and Fruit Set

Q: Can boron be mixed with other treatments?

Yes, some formulations are designed to be mixed into your regular treatment. Run a mixing test and check the technical data sheet.

Q: Which crops need the most boron?

Fruit trees, grapevine, olive, citrus, brassicas, sugar beet and crops with multiple flowering flushes such as strawberry.

Quick answer: boron is essential for pollen to germinate and the pollen tube to grow: without enough boron there's poor fertilization, flower drop and misshapen fruit. It also helps make better use of calcium. Molybdenum is involved in nitrogen use and enzymatic activity. Both are mainly applied as a foliar spray before and during flowering, with carefully adjusted doses, since the margin between boron deficiency and excess is narrow.

Deficiency symptoms

Boron: poor fruit set, flower drop, misshapen or cracked fruit, dying terminal shoots, thick or deformed young leaves.
Molybdenum: pale leaves resembling nitrogen deficiency, curled or necrotic margins; more common in acidic soils.

Which product to choose

Product	Composition	Recommended for	Recommended dose
Florecer Boro	11% soluble boron, high purity	Correcting boron deficiencies during flowering	Foliar or broadcast; ask our team
Rociada	2% soluble boron in a plant-based complex, with detergent and surface-drying effect	Boron supply during flowering while cleaning the leaf surface	Fertigation 3-4 L/ha · Foliar 1.5-2.5 L/ha
Polinia Premium	2% boron + 0.02% molybdenum with wetting adjuvants	Grapevine, fruit trees, tropical crops (mango, cherimoya, persimmon), citrus, strawberry and raspberry	Foliar 2-2.5 L/ha
Follaje Premium	2% molybdenum	Molybdenum deficiencies and leaf recovery	Foliar 2-3 L/ha
Fluvia	2% boron + 0.5% silica with a plant-based wetting complex	Humid periods: reduces surface moisture on the leaf; mixes with your regular treatment	Foliar; ask our team

For a more complete boost to flowering, combine boron with biostimulants such as Esencia Premium (amino acids and micronutrients bound to seaweed), Florecer Max, or, in melon and watermelon, Impulso Fruital.

When to apply boron

Pre-flowering (flower bud): the most effective moment to ensure good fruit set.
Full flowering: a second application in crops with staggered flowering.
Post-harvest in fruit trees: so buds build up reserves for the next flowering.

Precautions

Don't exceed the recommended doses: excess boron is toxic and burns leaf margins.
Avoid applying during the hottest hours of the day.
If you're already using a multi-deficiency corrector that contains boron, factor that in so you don't double up the supply.

Frequently asked questions

What is boron used for during flowering?

It allows pollen to germinate and the pollen tube to reach the ovule. With boron deficiency, fertilization fails, flowers drop, and fruit sets poorly or comes out misshapen.

Can boron be mixed with other treatments?

Yes, products like Polinia Premium or Fluvia are designed to be mixed into your regular treatment. Always run a mixing test beforehand and check the technical data sheet.