The Blueberry News – July 2019

16 | The Blueberry News FloridaBlueberryGrowers.org

topic of the season

continued from page 14

continued on page 18

Pest/

Problem

Management

Options

Amount of

Formulation

per Acre

Effectiveness

(Least = + to most

= +++++)

REI

(restricted

entry

interval)

PHI

(postharvest

interval)

Comments

Algal stem

blotch

Make applications after harvest on a monthly interval

following bacterial canker use instructions.

Ensure good cane coverage and canopy penetration.

Do not mix with Aliette, any phosphite fungicide, or any

acidifying agents. Do not exceed 28 lb. per acre per

year. Copper products provide preventive management

of algal stem blotch only.

Kocide 3000 1.75–3.5 lb. ++ 48 h0 days

TABLE 8. LATE-SEASON AND POSTHARVEST BLUEBERRY DISEASE MANAGEMENT

CONTINUED

Septoria and

anthracnose

leaf spots

and

Phytophthora

root rot

Many formulations and products that contain copper

are labeled for use on blueberry at various rates

and application intervals. Carefully follow all label

instructions for any product to avoid phytotoxicity. Algal

stem blotch is not likely to specifically appear on the

label, but these products can be used as long as the

crop and site is on the label.

Other copper

products

Apply Aliette® as a foliar spray for Phytophthora and

Pythium root rots and Septoria leaf spot.

Subsequent applications can be made at 14- to 21-day

intervals. Two or three fungicide applications following

harvest are generally sufficient to prevent major

outbreaks of Septoria leaf spot.

Assuming that hedging is conducted immediately

following harvest, this is a good time to consider

an application. Do not exceed four applications per

acre per year.

Do not tank mix with copper and foliar fertilizers, and do

not apply in acidic water or add acidifying agents because

these practices could damage fruit or foliage. When tank-

mixing this product with others, test the mix on a small

area to make sure that phytotoxicity does not occur.

Fosetyl-Al

(Aliette®

WDG)

5 lb. ++++ 12 h 12 h

Apply as a foliar spray for Phytophthora and Pythium.

Also effective against Septoria and anthracnose leaf spots.

Do not tank mix with copper and foliar fertilizers and do

not apply in acidic water or add acidifying agents because

these practices could damage fruit or foliage. When tank-

mixing this product with others, test the mix on a small

area to make sure that phytotoxicity does not occur.

Potassium

phosphite

(Prophyt®)

4 pt. ++++ 4 h 0 days

Apply as a foliar spray for Phytophthora and Pythium.

Also effective against Septoria and anthracnose leaf spots.

Do not tank mix with copper and foliar fertilizers and do

not apply in acidic water or add acidifying agents because

these practices could damage fruit or foliage. When tank-

mixing this product with others, test the mix on a small

area to make sure that phytotoxicity does not occur.

Mono- and

dipotassium

salts of

phosphorous

acid

(Agri-Fos®)

2.5 qt. ++++ 4 h 0 days

Subsequent applications can be made at 14-day intervals.

Apply immediately after harvest. Two or three fungicide

applications after harvest are generally sufficient to

prevent major outbreaks of Septoria leaf spot. When

hedging is conducted immediately following harvest, this

is a good time to consider an application. Do not exceed

1.44 qt. per acre per season. Do not apply more than two

sequential applications of Abound® before switching to a

fungicide with another mode of action.

Azoxystrobin

(Abound®)

6.2–15.4 fl.

oz.

Septoria and ++++ 4 h 0 days

anthracnose

leaf spots