How to Manage Pests UC Pest Management Guidelines Pathogens:
Rhizopus stolonifer and Monilinia spp. (Reviewed 3/09, updated
11/12) In this Guideline: SYMPTOMS AND SIGNS The first
indication of hull rot usually comes several weeks before
harvest, when leaves on a shoot wither and die. Closely examine
fruit on this shoot for a brown area on the outside of the hull
and either tan fungal growth in the brown area on the inside or
outside of the hull (this indicates Monilinia) or black fungal
growth on the inside of the hull (this indicates Rhizopus).
Fungi invade hulls and produce a toxin that kills the shoot
attached to the fruit. Because the shoot is killed, other green
fruit on the shoot don't mature and they remain on the tree
after harvest. The disease causes dieback of shoots and fruiting
wood that reduces productivity in future years. COMMENTS ON THE
DISEASE Almond hulls are susceptible to hull rot fungi from the
beginning of hullsplit until the hulls dry—a period that can
last from 10 days to 2 months depe