Fall

Monitor California red scale males using pheromone-baited sticky traps (March through October), plus additional methods (e.g. examine harvested fruit).

• Keep records (example red scale monitoring form—PDF).
• Distinguish male scales from scale parasites and other important insects caught in sticky traps.

Monitor fruit for scale infestation and percentage red scale parasitism by Aphytis melinus and Comperiella bifasciata (August through October).

• Keep records of fruit monitoring results (example red scale fruit count monitoring form—PDF).

Release Aphytis melinus if biological control is compatible with the overall management program.

Monitor (November through March, depending on the date of harvest) for bean thrips in navel oranges, mandarins, and other export citrus that may be exported to Australia and New Zealand.

• Check with the California Citrus Quality Council (CCQC) for current export protocols and requirements.
• If trapping, distinguish bean thrips from other thrips species caught in sticky traps.

Monitor for Asian citrus psyllid by conducting visual surveys of newly forming flush, and by using sweep net surveying or tap sampling. Manage according to the Citrus Pest Management Guidelines. In areas where Asian citrus psyllid is not known to have established (central and northern California), if Asian citrus psyllid is found, contact your local county agriculture commissioner’s office, and report the location.

In areas of California where Asian citrus psyllid is established (southern California), participate in areawide treatment sprays. For maps of the distribution of Asian citrus psyllid and huanglongbing, see the UC ANR Asian Citrus Psyllid Distribution and Management website.

A CDFA liaison will provide research-backed information on Asian citrus psyllid management and coordinate treatments of commercial citrus.

Look for citrus leafminer (June through November) in young citrus orchards (less than 5 years). Manage if needed according to the Citrus Pest Management Guidelines.

Continue Fuller rose beetle treatments in orchards with fruit destined for Korea:

• Trees must be skirt-pruned and maintained sufficiently to prevent tree skirts from contacting the ground from June until harvest.
• Weed control must be practiced sufficiently to prevent a bridge forming from the ground to the skirt from June until harvest.
• Determine current protocols for managing Fuller rose beetle in accordance with the Citrus Pest Management Guidelines.
• Check with the California Citrus Quality Council (CCQC) for current export protocols and requirements.

Maintain records of the above in case they are needed by the packinghouse or APHIS.

Look for aggregations of leaffooted bug and manage their populations if they are damaging harvestable citrus fruit.

Look for other pests and their damage to fruit or damage to leaves and twigs, especially:

• Brown garden snail
• Citricola scale (second instars, November through March)
• Potato leafhopper (September through December)
• Texas citrus mite (October through December)
• Kanzawa mite (October)

Manage if needed according to the Citrus Pest Management Guidelines.

Look for diseases that cause symptoms on fruit, leaves and twigs, and on limbs, trunks, and roots, especially:

• Anthracnose (tear stain and anthracnose rot of fruit)
• Armillaria root rot
• Bacterial blast (Citrus blast)
• Brown rot decay and Septoria spot of fruit (if fruit is likely to be exported to China or Korea respectively, then these diseases are of concern).
• Dry root rot
• Phytophthora gummosis (crown and trunk) and Phytophthora root rot
• Rind disorder (Mandarin rind disorder—treat with oil or water repellants at color break)
• Stubborn disease

Record the date and location of problem trees or sites. Manage if needed according to the Citrus Pest Management Guidelines.

• Survey weeds. Manage vegetation if needed according to the Citrus Pest Management Guidelines.

• Determine whether a preventive application of certain treatments is warranted, including:

  • Fruit rot, rind disorder, and twig blight (bacterial blast) protectants for diseases listed above.
  • Whitewash to preserve fruit quality and to reduce fruit drop and sunburn (new plantings).

  Apply if needed according to the Citrus Pest Management Guidelines.

Provide proper cultural care and good growing conditions, including:

• Sample leaf nutrient levels at least once mid-August through October.
• Fertilize if needed.
• Irrigate and adjust scheduling to meet trees' varying water needs.
• Provide frost protection (PDF) when cold threatens.

Determine whether application of a plant growth regulator is warranted. Consider

• Gibberellic acid (GA3) to prevent fruit senescence in grapefruit, lemons, limes, navels, and pummelo.
• 2,4-D to reduce preharvest fruit drop of navels, Valencias, and grapefruit.

Harvest mature fruit in coordination with other management activities to ensure good postharvest fruit quality and food safety.

• Educate and supervise workers regarding fruit-handling Best Management Practices (BMPs)
• Inspect fruit quality before bins are moved from the picking site to identify grove areas where management practices need improvement.