Commercial Blackberry, Strawberry, and Blueberry Insect and Disease Control – 2015

The amount of insecticide or fungicide to use is given in per gal amounts for the home or backyard grower and in per 100 gal/acre amounts for the commercial grower. The home or backyard grower can determine the amount of spray needed to cover their plants completely by filling their sprayer with water and then spraying their plants until the water is almost ready to drip off the leaves. Determine how much water was used and add the correct amount of chemical from the appropriate table below. Commercial growers should calibrate their sprayers by spraying a measured area, measure the amount of water needed to refill the tank. Divide this amount by the fraction of an acre sprayed to get the gallons applied per acre. Mix the amount of chemical desired per acre with water to give this much spray material.

 

BLACKBERRIES*

For commercial growers, use the rate/acre column regardless of the amount of water you are spraying per acre. Read and follow all label directions. For home gardeners, if no rate is given then the product(s) are not recommended for home use.

 

Table 1.

Table 2.

r Restricted Use Pesticide

1. See Table 1 for date of last application prior to harvest.
2. tbs = tablespoon; lb = pound; gal = gallon.
3. Apply Brigade 2EC 2-4 qt/acre in a minimum of 100 gal of water as a drench to the crown area and lower canes. Drench will kill borers already hatched in soil. Applications made in fall Oct.-Nov. will have the best efficacy. Not recommended for homeowners.
4. Raspberry crown borer is a significant pest of caneberries in Oklahoma and will eventually cause the demise of plants if left uncontrolled. Seasonal treatment each year is recommended. Capture applied in late October or early November as a soil drench to the lower canes and soil around the canes will provide excellent control if adequate (50-100 gallons/acre) water is applied with the material. This is a restricted use chemical, not recommended for home-owners.
5. Red necked cane borer – The red necked cane borer is a 1/4 inch long beetle with a black head and wing covers, and a reddish thorax. Adults are typically present in brambles from May until June. Larval stage red necked cane borers tunnel within canes in a spiral fashion, producing 3” long swollen, galled areas. Galled canes should be rouged out and destroyed whenever they are found. Insecticide applications are only effective on the adults. In blocks with a history of red necked cane borer injury, scout for adults in May. Application of insecticides at petal fall and again in 10 to 14 days typically provides good control of red necked cane borer. Keep records to help refine pest management efforts in subsequent years.
6. Spotted Wing Drosophila (SWD) is a new invasive insect pest that has been detected recently in many states including Oklahoma in 2013. The adult females lay their eggs in ripe fruit. After hatching, the larvae feed and cause damage to the fruit. Monitoring traps and ripe fruit should be evaluated weekly from ripening until harvest. A spray program should begin when SWD is detected in monitoring traps or fruit. Sprays should be timed 7 days apart unless a rain event occurs then reapplication will be necessary.

 

* All diseases, information and fungicide treatments are applicable to both blackberries and raspberries unless otherwise noted.

 

STRAWBERRIES

Read and follow all label directions. For commercial growers, use the rate per acre column, regardless of the amount of water you are spraying per acre. For home gardeners, if no rate is given then the product is not recommended for home use.

 

 

Table 3.

 

 

Table 4.

 

Table 5.

1. See Table 1 for date of last application prior to harvest. If no number is provided then that chemical cannot be used on that crop
2. tbs = tablespoon; tsp = teaspoon; pt = pint; qt = quart; lb = pound; gal = gallon.
3. Rally is highly effective for control of powdery mildew and leaf blight. Captan and will not control powdery mildew. Cabrio, Pristine, and Abound are registered for Leafspot, Powdery Mildew and Anthracnose.

 

* Spotted Wing Drosophila (SWD) is a new invasive insect pest that has been detected recently in many states including Oklahoma in 2013. The adult females lay their eggs in ripe fruit. After hatching, the larvae feed and cause damage to the fruit. Monitoring traps and ripe fruit should be evaluated weekly from ripening until harvest. A spray program should begin when SWD is detected in monitoring traps or fruit. Sprays should be timed 7 days apart unless a rain event occurs then reapplication will be necessary.

 

BLUEBERRIES

For commercial growers, use the rate/acre column regardless of the amount of water you are spraying per acre. Read and follow all label directions. For home gardeners, if no rate is given, then the product is not recommended for home use.

 

 

 

Table 6.

 

Table 7.

 Table 7. cont

 

1. See Table 1 for date of last application prior to harvest.
2. tbs = tablespoon; tsp = teaspoon; pt = pint; qt = quart; gal = gallon; lb = pound3Apply only if these diseases are a problem. Observe harvest restrictions.

r Restricted Use Pesticide.

** Spotted Wing Drosophila (SWD) is a new invasive insect pest that has been detected recently in many states including Oklahoma in 2013. The adult females lay their eggs in ripe fruit. After hatching, the larvae feed and cause damage to the fruit. Monitoring traps and ripe fruit should be evaluated weekly from ripening until harvest. A spray program should begin when SWD is detected in monitoring traps or fruit. Sprays should be timed 7 days apart unless a rain event occurs then reapplication will be necessary. See the OSU SWD fact sheet for more information on monitoring and management of SWD.

 

TABLE 1. DAYS WAITING TIME - LAST APPLICATION BEFORE HARVEST

 

 

r Restricted Use Pesticide.

*Guthion 2L - up to 3 oz - 0 days; above 3 oz - 7 days. Application by backpack or hand wand sprayers is prohibited. Re-entry period is 4-5 days, 5 days if area receives less than 24 inches of annual rainfall.

Publications that may be helpful: Fact Sheets HLA-6213, Weed Management in Small Fruit Crops; HLA-6214, Growing Strawberries in the Home Garden; EPP-7612, Plant Disease Diagnostic Service; HLA-6239, Commercial Blackberry Production; HLA-6215, Home Culture of Blackberries.

 

CULTURAL CONTROL METHODS

With more chemicals being removed from the market, growers must have successful ways of controlling disease and insects through cultural means. Disease and insects may be controlled or the effects of these pests can be reduced using cultural methods. The methods to consider are site selection, maintaining good soil conditions, sanitation, and purchase of healthy, and where available, resistant varieties.

A well chosen site includes good air drainage to reduce spring frost damage, circulation, and adequate soil water drainage. Sites with these qualities improve plant growth and decrease plant susceptibility to insects and disease. Orienting rows for good sun exposure and natural air movement will dry leaves and fruit quickly. Raised beds improve soil drainage and reduce infections by root diseases. Proper site selection to decrease plant stresses, such as cold injury and buffeting by winds, can reduce attack by insects and diseases. New plantings located near old established areas may have greater risks of insect and disease populations from the old sites than plantings on isolated areas. Destroying native plant species in the immediate area that harbor harmful insects or diseases can reduce pest problems.

An important disease and insect control procedure is the planting of adapted, healthy, disease and insect resistant varieties. Plants should be purchased from reliable sources, and only healthy looking stock planted. Variety selection should be based on adaptation to the area, such as cold hardiness, heat tolerance, adaptation to soils, and ability to produce acceptable yields of high quality fruit. Varieties will vary in the degree of susceptibility to an insect or disease. The nursery, supplier or county agent should have a recent list of adaptive and resistant cultivars that are available for planting in Oklahoma.

Maintaining proper soil moisture and fertilization can insure healthy plants. These plants will be more resistant to disease and insect damage than plants over or under fertilized or watered. Annual leaf analysis and soil analysis can be used to determine fertilization rates. Rainfall and soil moisture should be monitored to determine when to irrigate plants. Tensiometers, watermarks or some other form of measuring soil moisture may be used to determine when irrigation is necessary in larger plantings. This may not be necessary in smaller plantings where rainfall and stress of plants can be monitored directly.

 

Sanitation is important in controlling some insects, and especially in controlling diseases. Diseased and dead branches should be removed and when necessary, entire plants should be removed to reduce overwintering sites for insects and pathogens. These infected materials should be burned or removed from the site. Unharvested fruit, leaf litter and pruning’s should be removed to decrease the spread and population increase of insects and diseases. Pruning equipment should be disinfected before, during and after use to avoid transmitting disease during pruning. A solution of 10% chlorine bleach and 90% water is a good disinfectant.

Weed control is essential for plant growth and production. Economic losses due to weeds are sometimes greater than those caused by insects or diseases. Weeds compete directly with crops for nutrients, water and light and serve as hosts for insects and diseases. Weeds may also interfere with pesticide application, harvesting and air circulation in planting. To control weeds, an integrated program using cultural practices (such as pulling or hoeing weeds) along with herbicides is the most effective. Suitable herbicides for weed control in small fruit plantings are listed in Fact Sheet 6243, “Weed Control in Small Fruit Crops.”

The above cultural practices along with timely applications of pesticides will produce high quality fruit. It is usually necessary to use each of these cultural methods along with pesticides to attain good control leading to healthier plants, higher quality fruit and greater yields.

Following is a list of specific cultural methods for controlling various insects and diseases in blueberry, strawberry and blackberry production. These methods can be used alone or in conjunction with insecticides and fungicides to limit the spread of insects and diseases.

 

BLUEBERRY

Red and necrotic ringspot and blueberry stunt

Plant disease-free stock. Remove and burn diseased plants. Control insects which may be vectors of disease.

 

Phytophthora root rot
Limit movement of soil and water to lessen disease damage.

 

Anthracnose
No cultural method of control.

Botrytis, blossom and fruit rots
Ensure good air circulation and sun exposure to quickly dry wet leaves.

 

Phomopsis twig and cane blight
Prune and burn diseased wood.

 

Stem canker (various fungi)
Purchase disease-free stock. Purchase resistant varieties. Remove dead and dying branches 6-8 inches below diseased wood.

 

Climbing cutworm
Hand pick off of blossom when they become numerous enough to warrant control.

 

Blueberry bud mite
Selectively prune out old canes to reduce populations. Choose non-susceptible varieties.

 

Fall webworm
Destroy webs by hand.

 

STRAWBERRY

 

Strawberry weevil
Use the same bed less than three years. Plow under old beds immediately after harvest. Renovate existing beds by mowing or removing foliage and mulch.

Mites
Purchase mite-free stock. Isolate new plantings from established plantings. Make sure plants are healthy and well-watered. Use a water hose to wash mites from plants.

Lygus bugs
Control weeds in and near planting to reduce host plants from insects and disease.
Weeds or alfalfa that have been growing should not be removed during the strawberry blossom period, because the insects will move into the strawberries.

Leaf spot
Plant disease-free stock.

Powdery mildew
Kill or burn leaves which fungal structures are on. Purchase resistant varieties.

Leaf scorch
Frequent renewal of plantings. Purchase resistant varieties.

Anthracnose
Remove plant debris and mulch. Purchase resistant varieties, where available. Use only enough fertilizer to establish plants, but do not over fertilize them. If any signs of anthracnose occur, discontinue all applications of nitrogen and potassium.

 

BLACKBERRY

 

Anthracnose
Remove and burn old canes.

Cane borers
Remove and burn infested canes.

 

 

Jackie Lee

Extension Entomologist

 

Phil Mulder

Extension Entomologist

 

Damon Smith

Former Extension Plant Pathologist