IFAS Extension
Application Timing Recommendations
- Only certain blocks with poor air or water drainage are vulnerable to brown rot.
- Most problematic on early-maturing sweet oranges and Navel.
- Applications should start in mid-July with a product with FRAC P 07 mode of action.
- Can get full-season protection if not severe.
- Rotate products if more than one application is needed. Resistance to FRAC MOA P 07 products has been reported in California, but not in Florida yet.
- Copper can be used in August before or after symptom development.
- 2–4 lb of metallic copper is recommended.
- Can give 45–60 days of protection.
- If brown rot starts unexpectedly, Orondis Ultra (FRAC MOA 40+49) or Revus (FRAC MOA 40) are good choices.
- Give at least 30 days of protection.
- Resistance in other Phytophthora spp. has been reported. Carefully rotate modes of action.
Recommended Chemical Controls
READ THE LABEL.
See Table 1.
Rates for pesticides are given as the maximum amount required to treat mature citrus trees unless otherwise noted. To treat smaller trees with commercial application equipment including handguns, mix the per-acre rate for mature trees in 250 gal of water or the recommended rate listed in Table 1. Calibrate and arrange nozzles to deliver thorough distribution, and treat as many acres as this volume of spray allows.
Table 1. Recommended chemical controls for brown rot of fruit.
|
Pesticide |
FRAC MOA1 |
Mature Trees Rate/Acre2 |
|---|---|---|
|
Aliette WDG |
P 07 |
5 lb or 1 lb/100 gal — No more than 4 applications per year for all uses and no more than 20 lb/acre. Do not apply within 30 days of harvest. |
|
Orondis Ultra |
40 + 49 |
5.5–8.0 fl oz — Maximum 1 application a year, and do not apply more than 8 fl oz (0.02 lb a.i. oxathiapiprolin and 0.13 lb a.i. mandipropamid). |
|
Phostrol |
P 07 |
4.5 pt — Can cause phytotoxicity if applied above 90°F, at color break, or after rainfall. |
|
ProPhyt |
P 07 |
4 pt — Recommended application volume of 100–205 gal/acre. Do not apply at extreme low or high temperatures. |
|
Revus |
40 |
8.0 fl oz — Maximum 2 applications a year with a minimum 30-day retreatment interval. Do not apply more than 16 fl oz (0.26 lb a.i.)/year. |
|
Copper fungicide |
M 01 |
Use label rate. |
|
1 Mode of action class for citrus pesticides from the Fungicide Resistance Action Committee (FRAC) 2025. Refer to chapter 4, “Pesticide Resistance and Resistance Management,” for more details. 2 Lower rates may be used on smaller trees. Do not use less than the minimum label rate. | ||
