PHOSGUARD CALCIUM BO

PHOSGUARD CALCIUM BO is the flowering and fruit-set grade, a liquid phosphite that carries calcium and boron into the reproductive stage of the crop. Where the base grades lead on defence alone, this one pairs systemic plant-health activity with two elements that govern successful flowering and fruit development: calcium for cell-wall integrity and fruit firmness, and boron for pollen viability and fertilisation. It is built for the window from flowering through early fruit growth, when structural quality and set are decided. The grade fits foliar and fertigation programmes on fruit and vegetable crops.

Key Benefits

• Switches on the plant’s defence response. Phosphite primes phytoalexin and phenolic synthesis and cell-wall reinforcement, keeping the crop’s own defences active through the reproductive stage.
• Hardens the crop against oomycete pressure. The phosphite is directly unfavourable to organisms such as Phytophthora and the downy mildews, adding protection when flowers and young fruit are most vulnerable.
• Supports flowering and fruit set. Boron underpins pollen viability and pollen tube growth, improving fertilisation and set at the reproductive stage.
• Builds structural fruit quality. Calcium is incorporated into cell walls and middle lamellae, giving developing fruit firmness and resistance to physiological disorders.
• Moves systemically to new growth. Full translocation carries the activity into the expanding flowers and fruit a spray cannot fully reach.

How It Works

PHOSGUARD CALCIUM BO delivers phosphite, the phosphonate ion, which crops absorb quickly and move systemically through both xylem and phloem after a foliar spray or fertigation application. Inside the plant, phosphite acts in two complementary ways that depend on concentration. At higher local concentrations it is directly unfavourable to oomycete organisms such as Phytophthora, Pythium, and the downy mildews, slowing their growth and energy metabolism. At lower concentrations it primes the crop’s own defence system, triggering the synthesis of phytoalexins and other phenolic compounds, reinforcing cell walls with lignin and suberin, and raising the activity of defence-related enzymes. Because it is fully systemic, the protection reaches new growth and tissues the spray never directly contacted.

Calcium and boron add a distinct, structural role at flowering and fruit set. Calcium is built into cell walls and middle lamellae, giving developing fruit firmness and resistance to physiological disorders, while boron is essential for pollen viability, pollen tube growth, and successful fertilisation. Delivering these two elements alongside systemic defence support makes this grade a reproductive-stage tool as much as a plant-health one.

When to Use PHOSGUARD CALCIUM BO

PHOSGUARD CALCIUM BO is targeted at the reproductive window, from flowering through early fruit growth.

• Apply PHOSGUARD CALCIUM BO from early flowering to support pollen viability and fruit set.
• Use PHOSGUARD CALCIUM BO through early fruit growth to build cell-wall integrity and firmness.
• Include PHOSGUARD CALCIUM BO in foliar or fertigation programmes on fruit and vegetable crops at the reproductive stage.

Plants mount their strongest defences when they are healthy and unstressed; when a crop is under pressure those responses slow, which is exactly when systemic support earns its place. Applying ahead of and through high-pressure periods keeps the crop’s defences primed when it cannot fully prime them on its own.