Botanic Garden >> Gardening > >> Question and Answer >> Plant Diseases

Rotten Pecans: Weather, Scab, and Alternate Bearing

Pecans that are watery, shriveled, or rotten often reflect weather during the previous growing season—drought during nut fill or excess rain at harvest. Pecan scab (fungal spots on leaves and shucks) is the main disease, but alternate bearing (heavy crop one year, light the next) is genetic and normal.

Checklist

How did the crop look last two years?
Are nuts watery, shriveled, or scabby?
Search "pecan scab" images to match symptoms.
Soil test for nutrient balance (via county extension).

If scab is confirmed, resistant cultivars and timed fungicide sprays are the commercial approach; homeowners can focus on sanitation (remove fallen shucks) and tree health.

Plant Diseases: Pecan Tree Limb Drop: Drought, Weevils, and Borers; Pecan Red Kernels and Casebearer Larvae: Spray Schedule Necessity; Chitalpa Dieback: Prune Dead, Encourage Basal Sprouts; Pecan Nuts Poor Quality Two Years Running: Soil Test and Water; Pecan Nuts Moldy or Shriveled: Water Stress, Not Disease; Pecan Tree No Nuts: Water, Zinc, Fertilizer, Pruning Guide; Pecan Tree Nut Problems: Weevils, Scab, and Spray Schedule; Why Tree Roses Die in Winter & How to Protect Them; Pecan Trees Not Bearing: Fertilize, Water, Soil Test; Managing Zinc Deficiency in a Mature Pecan Tree

Garden Articles

Pecan Tree Black Nuts and Spider Webbing: Phytophthora Root Rot and Harmless Barklice

Pecan Tree Bark Exfoliation: Normal Aging Process, Not Disease

Lilac Damaged by Hornets? Likely Secondary to Underlying Decline

Eliminating Invasive White Mulberry Tree Near Fence

Shipping Georgia Pecans: Growers Association Lists Shippers

Replacing a Pecan Tree: Choose Scab-Resistant Varieties

Pecan Phylloxera: Gall Management and Nut Production Protection

Plants

Mushrooms at Base of 50-Year-Old Mimosa: Possible Root Disease

White Oak Progressive Branch Dieback: Internal Decay Suspected

Chanticleer Pear Crown Decline: Rootstock Issues and Need for On-Site Evaluation

Green Growth on Old Pecan Trees: Resurrection Fern or Lichens

Paper Birch Decline: Testing for Life and Making the Call

Pecan Tree Bark Peeling: Normal Aging Process

Pecan Phylloxera: Timing Sprays for Gall Prevention