Field Identification
The poster child for humid pecan country—olive-black velvety lesions on leaves, petioles, and nuts that turn crop into a scab museum. Susceptible cultivars in crowded, dew-heavy orchards get hammered first.
Lesions start small and expand under prolonged leaf wetness; infected nuts show black sunken spots and may drop early. Conidia splash and wind-dispersed spores reinfect all season in rainy years.
How to Deal With It
Organic Control Methods
Sulfur rotations and copper products per organic rules; lime sulfur may be used in dormant windows on tolerant timing. Biofungicides with Bacillus subtilis or Reynoutria extracts can supplement—not replace—sanitation in wet years.
Antagonistic bacteria and yeasts applied to foliage compete for infection sites when humidity is high.
Plant resistant cultivars; widen spacing and prune for sun and air movement; destroy fallen leaves where practical; avoid overhead irrigation.
Shake limbs after harvest to dislodge old foliage in small plantings; use reflective ground cover in research trials to speed drying.
Scout at leaf out and nut sizing; begin protectant programs before first spring rains on susceptible varieties.
Let Nature Handle It
Natural Enemies
- Antagonistic Bacteria
- Competitive Yeasts
- Hyperparasitic Fungi