Troubleshooting
Pecan 'Desirable' problems — and how to fix them
Pecan 'Desirable' (Carya illinoinensis 'Desirable') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Pecan scab
'Desirable' is highly scab-susceptible; this fungal disease blackens husks and leaves and ruins crops in humid regions. Best grown in drier climates or with a rigorous fungicide programme.
Alternate bearing
Tends to crop heavily one year and light the next. Thinning excess nutlets and steady irrigation and feeding smooth the cycle.
Zinc deficiency (rosette)
Shows as small, crinkled, bunched leaves on shortened shoots. Correct with foliar zinc sulphate sprays during spring flushes.
Poor pollination
A protandrous (Type II) cultivar; without an overlapping protogynous (Type I) pollinator such as 'Pawnee' nearby, nut set is sparse.
Prevent pecan 'desirable' problems before they start
Most pecan 'desirable' issues are care-mismatch, not bad luck. Dial in the basics:
Looking for pecan 'desirable' in general rather than its problems? Read the full pecan 'desirable' care guide — light, water, soil and feeding.
Pecan 'Desirable' problems — FAQ
Why is my pecan 'desirable' pecan scab?
'Desirable' is highly scab-susceptible; this fungal disease blackens husks and leaves and ruins crops in humid regions. Best grown in drier climates or with a rigorous fungicide programme.
Why is my pecan 'desirable' alternate bearing?
Tends to crop heavily one year and light the next. Thinning excess nutlets and steady irrigation and feeding smooth the cycle.
Why is my pecan 'desirable' zinc deficiency (rosette)?
Shows as small, crinkled, bunched leaves on shortened shoots. Correct with foliar zinc sulphate sprays during spring flushes.
Why is my pecan 'desirable' poor pollination?
A protandrous (Type II) cultivar; without an overlapping protogynous (Type I) pollinator such as 'Pawnee' nearby, nut set is sparse.