PHOSGUARD AL

PHOSGUARD AL is the aluminium phosphite grade, formulated for the most demanding oomycete situations. Pairing phosphite with aluminium gives this liquid an additional direct effect against organisms such as Phytophthora and the downy mildews, on top of the systemic defence response the phosphite primes in the plant. Fully systemic, it carries that protection to both root tissue and new canopy, which makes it well suited to root-disease-prone crops. It is the most robust grade in the range for crops under sustained pressure, applied through foliar or fertigation programmes.

Key Benefits

• Triggers the crop’s defence machinery. Phosphite primes phytoalexin and phenolic synthesis and cell-wall reinforcement, putting the plant’s own defences on alert.
• Delivers robust resilience to oomycete pressure. The aluminium phosphite form adds direct activity against oomycetes through aluminium ions and a low formulation pH, on top of the induced defence response.
• Protects both roots and foliage. Full systemic movement carries the activity to root tissue and new canopy alike, suiting root-disease-prone crops.
• Fits sustained, preventive programmes. Applied through fertigation or as a foliar spray, it supports crops where Phytophthora and downy mildew pressure builds across the season.

How It Works

PHOSGUARD AL 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.

In this grade the phosphite is paired with aluminium. The aluminium phosphite form contributes additional direct activity against oomycete organisms, through aluminium ions and a low formulation pH, on top of the systemic defence priming the phosphite provides. The combination gives this grade the most robust profile in the range for crops facing sustained root and foliar oomycete pressure.

When to Use PHOSGUARD Al

PHOSGUARD AL is reserved for crops under sustained, heavy oomycete pressure, above and below ground.

• Apply PHOSGUARD AL preventively where Phytophthora or downy mildew pressure is sustained through the season.
• Use PHOSGUARD AL through fertigation to support root health on root-disease-prone crops such as avocado and citrus.
• Include PHOSGUARD AL as a foliar spray to carry protection into new canopy growth.

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.