Crop Profile for Blackberry in Oregon
Prepared , August 2002
General Production Information
Production Facts (5, 7, 9, 12):
Production Regions (11, 12):
Almost all of Oregon's blackberries
are grown west of the Cascade Mountains in the Willamette Valley. Fertile soils,
mild winters and cool summers allow growers to produce high quality berries with
good flavor and color. Marion County has the most blackberry acreage in the
state (approximately 50%), followed by Clackamas County (approximately 20%).
Other Willamette Valley counties producing blackberries include Benton, Lane,
Linn, Multnomah, Polk, Washington and Yamhill.
Cultural Practices (6, 7, 8, 11, 12):
Three types of blackberries are grown in Oregon: erect, semi-erect and trailing. However, the trailing type, which includes hybrid berries like Boysenberry and Loganberry, is the most prevalent and accounts for 92 to 94% of all the blackberries grown in Oregon. 'Marion' (commonly known as Marionberry) is the most widely planted cultivar of the trailing type, accounting for about 60% of the total blackberry acreage. 'Oregon Thornless Evergreen' and Boysenberry each account for about 15% of the blackberry acreage. Other cultivars of the trailing type, and the erect and semi-erect types, account for the remaining acreage.
Blackberries are perennial plants that produce fruit on biennial canes: The canes grow one year (primocanes) and produce fruit the following year (floricanes). The floricanes die after they have fruited. New canes are produced each year from the roots or the base of old canes. These primocanes are kept on the ground and allowed to grow throughout the season, generally reaching a length of 10 to 20 feet long. The floricanes are removed each year after harvest and the new primocanes, which will fruit the following year, need to be trained, generally in September, to a trellis of posts and wire. A trellis system is necessary to support the canes and subsequent fruit load, and help facilitate harvesting with a harvesting machine. The removal of dead floricanes and training of new primocanes is labor intensive and done exclusively by hand.
Perennial weeds are generally controlled prior to planting with a non-selective herbicide, such as glyphosate, in the fall or early spring. In preparation for planting, the soil is disked and cultivated to produce a smooth surface. Tissue culture plants are common and are planted in early spring. The plants grow vegetatively the first year and will produce a "baby crop" on those canes the second year. Often times, however, growers don't harvest the baby crop but will wait until the third year to harvest a full crop. A preemergence herbicide is applied after planting and again in the fall. It is often necessary to have a crew hand-hoe the soil to create a vegetation-free area to which the preemergence herbicide is applied. Perennial sod is often established and maintained in the row middles; vegetation-free row middles, accomplished by disking and/or herbicides, are common also. Irrigation is necessary after planting and weekly, thereafter, until rainfall begins in early fall.
Some blackberry acreage (approximately 50% and mostly the cultivars Marion and Oregon Thornless Evergreen) is converted to an alternate-year (AY) system of production after the first few years of every-year (EY) production; the AY system allows plants to produce fruit once every two years, instead of annually. In an AY system, both floricanes and primocanes are cut and removed after harvest. Subsequently, only primocanes are produced the following year, with a fruit harvest the next year. This can reduce production costs with labor savings (floricane removal and primocane training is quicker and easier), and fewer pesticide and fertilizer inputs in the non-bearing year.
Primocane suppression or "caneburning" is a common practice in blackberry production. When primocanes are 4 to 8 inches tall, they are sprayed with a contact herbicide, such as carfentrazone (Aim) or oxyfluorfen (Goal), once or twice per season. The spray is directed to the primocanes and lower 18 inches of the floricane. Caneburning has been shown to reduce incidence of fungal diseases and increase yields the following year; it is also necessary to help facilitate mechanical harvesting.
Most (70% to 90%) 'Marion' and 'Oregon Thornless Evergreen' blackberries are harvested with a mechanical harvester while Boysenberries and Loganberries are mostly (approximately 80%) harvested by hand. Harvest season for each cultivar lasts about 3 to 4 weeks and berries are harvested every four to five days. Harvest begins in early July for most blackberry cultivars; harvest of 'Oregon Thornless Evergreen' begins in mid-August.
A blackberry planting can remain productive for 10 to 20 years; however, pressure from insects or disease can negatively impact plant vigor and yield and shorten the life of the planting. The raspberry crown borer, viruses, crown gall, root rot and cane and leaf spot are serious pests that often times reduce the longevity of a planting.
Insect Pests
Leafrollers are found in most blackberry plantings. While they don't cause serious damage to the plant or fruit, they can be a harvest contaminant, especially in fields that are machine harvested (10). Insect contaminants in the harvested fruit reduce fruit quality and can cause serious economic losses to the grower. Root weevils and other insects can be contaminants; about 70% of all blackberry acreage is treated with an insecticide to control insect contaminants and other insect pests in the blackberry crop (1). The raspberry crown borer is a serious pest and, due to its two year life cycle, difficult to control; it can reduce plant vigor and yield and, in severe infestations, cause plant death (14, 16). The twospotted spider mite is an occasional pest that can be problematic in times of warm, dry weather (14).
Aphids
Larger Raspberry Aphid (Amphorophora agathonica) and other
species
Crop Damage: Aphid feeding causes the leaves to curl downward and become deformed. Amphorophora agathonica can vector raspberry mosaic virus, which can cause substantial yield losses.
Chemical control:
Biological control:
Armyworms and cutworms
Many species
Pest description: Pale green to brown larvae of noctuid moths; 30 to 50mm long.
Crop damage: They feed on leaves and are usually nocturnal. They generally don't cause economic damage to the plants but can be a contaminant at harvest, especially in machine harvested fields.
Chemical control:
Biological control:
Insect contaminants at harvest
Crop damage: Plant or fruit is generally not damaged. Insect contaminants can reduce the value of the harvested crop.
Chemical control:
Cultural control:
Correct adjustment of air-blast or vacuum-suction
cleaner systems on a machine harvester can lessen insect contamination of
machine-picked berries.
Leafrollers
Obliquebanded leafroller
(Choristoneura rosaceana)
Orange tortrix (Argyrotaenia citrana)
Pest description: Larvae of the Obliquebanded leafroller are tan when small, changing to leaf-green with black heads as they mature. They are about 20 to 25mm in size when mature. There are two generations a year. Orange tortrix larvae are tan when small, changing to pale green with brown heads as they mature. They are 18 to 22mm long when mature. There are two or three generations a year.
Crop damage: The larvae web and feed on foliage and ripe fruit. They
are a contaminant in fruit that is machine harvested.
Chemical
control:
Insecticides are applied about 2 to 3 weeks after flight peak,
as determined by pheromone traps, or applied immediately when 75 or more moths
per week have been caught in pheromone traps.
Biological control:
Mites
Twospotted spider mite (Tetranychus
urticae) and others
Chemical control:
Biological Control:
Dryberry mite
Phyllocoptes gracilis
Pest description: This mite is microscopic and found on ripe berries, in cracks and crevices of canes, and under bud scales.
Crop damage: Affected berries turn red, then brown and dry; the whole fruit may be dry or just patches on the fruit. Dryberry syndrome also can have other causes, such as poor pollination or fungal disease.
Chemical control:
Redberry mite
Acalitus essigi
Pest description: A microscopic mite with four legs. They overwinter as adults in bud scales and cracks and crevices on the canes.
Crop damage: Late-maturing cultivars, like
Chemical control:
Dormant spray
Delayed-dormant spray (use
one)
Apply in spring after new growth is 2 to 6 inches long. These
products, rates, and times of application are labeled for disease control and
have been shown to prove redberry mite control. A dormant oil application at
this time, as well as in the fall, will also help control infestations.
Obscure root weevil
Sciopithes obscurus
Pest description: A snout beetle about 6 to 8mm long. They are predominantly gray with a wavy line across the wing covers. Larvae, which overwinter in the soil, are about 7mm when mature, legless, white and form a characteristic c shape.
Crop damage: Adult feeding on foliage causes leaf notching and larvae feed on the roots. However, neither life stage stresses the plant; the adults can be a contaminant in the harvested fruit.
Chemical control:
Biological control (larvae):
Beauveria bassiana (Mycotrol ES) at 1 to 3 quarts of product/A. Live fungal spores. 0 day PHI. 12 hour REI.
Raspberry cane maggot
Pegomya
rubivora
Pest description: Adults resemble small houseflies, are dark grey
and are about 6mm long. They emerge in April and lay eggs on tips of new canes.
Larvae are small, legless, and a translucent white color.
Crop damage: The raspberry cane maggot is an occasional pest in blackberries. The larvae feed downward in new canes, causing distinct drooping and creating a condition often referred to as limberneck.This pest causes very little loss, even when 60 to 70 percent of new canes are infested. Naturally occurring parasites control this pest most seasons.
Chemical control:
No suggested materials.
Raspberry crown borer
Pennisetia
marginata
Pest description: Adults are clear winged moths about
15mm long. The abdomen is black with yellow bands, which gives the adult the
appearance of a yellow jacket wasp. The overwintering first-year larvae are
white and about 6mm long. They begin to feed in early March on cane buds. By
May, the larvae bore into the harder portions of the cane and move downward
towards the crown. These larvae overwinter and begin feeding in the crowns the
following spring. By late summer, larvae are about 25mm long.
Crop damage: Feeding by young and mature larvae in roots and in crown weakens the plant and may cause death.
Chemical control:
Apply as a crown drench in late March or before
bud break. Use 100 to 300 gal/A, directing spray toward crown and lower portion
of canes and avoiding runoff. Rain should follow to move insecticide into the
root zone where the larvae feed.
Rose stem girdler
Agrilus
aurichalceus
Pest description: The adult is a wood-boring beetle,
6mm long, flat-headed, mostly black, with a coppery red thorax. They can be seen
on primocanes beginning at first bloom. Larvae are milky white, with the first
segment behind the head slightly yellow and the mouthparts brown to black.
Larvae are slightly flattened with body segments separated by distinct
constrictions. There are two short, brown, toothed projections on the tail end.
Not a common pest in Oregon blackberry fields.
Crop damage: Larvae feed inside primocanes, girdling canes and causing galls. Canes die or become low-yielding floricanes the next season. Canes are more susceptible to winter injury.
Chemical control:
No insecticides are labeled for control.
Insecticides registered for use on blackberries and that can be used with
relative safety to pollinators may provide some control of this pest if used on
a weekly schedule while adults are present.
Root weevils
Black vine weevil (Otiorhynchus
sulcatus)
Strawberry root weevil (O. ovatus)
Rough strawberry
root weevil (O. rugosostriatus)
Pest description: Adults are beetles and are generally black in color; individual beetles may appear light brown to chocolate-brown. They range in size from 6 to 12mm long. The black vine weevil is the largest and has small yellow patches on its back. Larvae overwinter 2 to 8 inches deep in the soil. They are white with tan heads, legless and have a characteristic cshape.
Crop damage: Adults appear after bloom, beginning in May and continuing through July. They feed on leaves prior to egg-laying, leaving characteristic notch marks on leaf margins, although this damage is usually insignificant to plant vitality. The larvae feed on small roots and later on the cambium of large roots and crowns and, at high populations, can reduce plant vigor and yield. The adults can cause economic losses as a contaminant in harvested fruit.
Chemical control (adults):
Cultural control:
Biological control:
Raspberry Sawfly
Monophadnoides
geniculatus
Pest description: The adult is a black wasp with red and yellow markings and clear wings, about 6mm long, lacking the typical narrow wasp-like waist. Larvae are pale green with conspicuous bristles and can be up to 20mm long.
Crop damage: In the late spring, larvae roll leaves and feed on undersides of leaf. Their feeding activity usually doesn't pose a problem but they can be contaminant in mechanically harvested fields.
Chemical control:
Slugs
Limax spp., Arion spp., Deroceras
spp.
Pest description: Slugs are closely related to snails but have no external shell. Color ranges from grey to brown to black; mature slugs are about 0.5 to 0.75 inches in length.
Crop damage: They may climb canes and move onto berries, on which they become contaminants. They are most likely to be a problem in cool, wet summers. Slugs migrate into and under crates taken to the field before harvest, so keep crates and pallets away from damp soil and grass.
Chemical control:
Snowy tree cricket
Oecanthus fultoni
Pest description: Light green to whitish crickets 12 to 20mm long. Young nymphs first emerge sometime in May; females lay eggs during the summer.
Crop damage: Females drill small holes in canes to deposit eggs. Large numbers of punctures can girdle and kill canes above punctures, or weaken canes which can split or break under stress from wind or fruit load. Egg punctures can also be entry points for disease. Eggs hatch and young crickets emerge about May.
Chemical control:
Stinkbugs
Euschistus conspersus, and other
species
Pest description: Large, bright green bugs, shield-shape and flattened.
Crop damage:. They are a contaminant in mechanically harvested berries.
Chemical control:
No insecticide is registered specifically for
stinkbug control. Asana XL applied for leafroller control before harvest may
provide some control.
Cultural control:
Correct adjustment of air-blast or vacuum-suction
cleaner systems can lessen insect contamination of machine-picked berries.
Strawberry crown moth
Synanthedon
bibionipennis
Pest description: Adults are clear winged moths about 12mm long. The abdomen is black with yellow bands, which gives the adult the appearance of a yellow jacket wasp. They appear in June and July. Newly hatched larvae are approximately 4mm long but reach 20mm at maturity. They are white with a brown head. Pheromone traps can be used to monitor adult activity.
Crop damage: Larvae girdle the roots and crowns lower crowns with superficial tunnels. Plants can be stunted and have poor vigor.
Chemical control:
Apply as a crown drench in late March or before
bud break. Use 100 to 300 gal/A drench, directing spray toward crown and lower
portion of canes and avoiding runoff. Rain should follow to move insecticide
into the root zone where the larvae feed.
Thrips
Frankliniella spp.
Pest description: Thrips are about 1mm long at maturity. Color
ranges from reddish yellow to dark brown. Wings are distinctly fringed.
Crop damage: They are common flower feeders and, when abundant, have been reported to cause blossom blasting. They can also feed on fruit. A toxin in their saliva can cause distortion, discoloration or destruction of plant tissue.
Chemical control:
Western raspberry fruitworm
Byturus
bakeri
Pest description: Adults are a brown beetle approximately 5mm
long. Larvae are about 8mm long, with tan and white bands and a brown head.
Crop damage: Adult feeding causes characteristic slits in leaves. Adult feeding can also destroy developing buds. Larvae feed within the blossom and in developing fruit.
Chemical control:
Winter moth
Operophthera spp.
Pest description: Adult moths are 8 to 12mm long and range in
color from tan to gray. Females are wingless but males fly and mate in late fall
and early winter. Larvae are 20 to 25 mm at maturity, light green with a green
head and a white strip down each side of the body. They loop when walking.
Crop damage: Larvae hatch in late winter/early spring and feed on buds. They can destroy fruit buds and, thus, reduce fruit yield. The winter moth larvae are occasional pests in blackberries, found early season through bloom.
Chemical control:
Biological control:
Diseases
The mild, moist conditions in Oregon's Willamette Valley and the dense foliage of the blackberry plant combine to create ideal conditions for disease development caused by various fungal organisms. About 80% of Oregon's blackberry acreage is treated with a fungicide at least once but, more often, several times per season (1). Products such as calcium polysulfide and copper hydroxide are widely used throughout most blackberry acreage. Fruit rot caused by Botrytis cinerea, is a wide-spread fungal disease (4). It causes lower quality fruit and/or reduced marketable yields and, if conditions are favorable for disease development, several applications of a fungcide per season are required for adequate control. Tank mixing or rotation with fungicides that have different modes of action are critical in a fruit rot control program to prevent likelihood of disease resistance (13). Switch (cyprodinil + fludioxonil) has been used for the past several years under Section 18 registration for fruit rot control while permanent registration is pending. Leaf and cane spot caused by Septoria rubi, and Purple blotch, caused by Septocyta ruborum, are two diseases found in most blackberry fields (13). In every-year production fields, a rigorous fungicide regime is required to control these diseases fields, which can reduce plant vigor and yield. Alternate-year production, as is common on many farms, breaks the disease cycle and fungicides to control these diseases are not usually needed.
Anthracnose
Elsinoe veneta
This fungus overwinters on infected canes. Hybrid berries, such as 'Boysenberry' and 'Loganberry', are not often infected. The disease is not always severe enough to warrant the cost of spraying. This disease is particularly serious if rains continue late into spring, when spots on canes may be plentiful enough to retard sap flow, thus girdling the canes. Early-season infections are more severe than late-season infections.
Symptoms: Small purple spots appear on canes, increase in size, and develop light gray centers with brownish purple borders. Spots commonly coalesce to form large irregular lesions. Canes may dry and crack. On leaves, minute purple spots develop which enlarge and coalesce to form gray to white areas. Partial defoliation may result. Berries may ripen prematurely and be small and dry.
Chemical control:
Apply late dormant or delayed dormant; further
control is not needed in most years.
Applications when new canes are 6 to 12 inches tall with the following
materials may be effective if disease pressure is great.
Cultural control:
Armillaria Root Rot
Armillaria spp.
This is a soil fungus that is often found on newly cleared land. In fall, clumps of honey-colored mushrooms may appear on crowns of infected plants. These discharge vast numbers of airborne spores, which become distributed widely in the area. Armillaria can survive saprophytically for years on dead roots and old cane stubs left in soil. White feltlike masses of fungus can be seen on the plant's crown. Scattered around the base of the plant are black shoestring-like strands called rhizomorphs. These hardened fungus strands grow through soil for considerable distances and may be one way the organism spreads from plant to plant. Rhizomorphs are also common within the root mass. Rhizomorphs look like black roots but are hollow.
Symptoms: The first visible disease symptom is a decline in vigor and dieback in which leaves turn yellow, wilt, and die. This may occur only on one side of the plant or in one or two canes.
Chemical control:
Methyl bromide fumigation has been found to give
the best, albeit limited, control.
Cultural control:
Cane and Leaf Rust
Kuehneola
uredinis
This fungus has several spore types that infect both floricane and primocane leaves. The fungus is not systemic in the plant. Wet conditions favor disease development. Elongate, yellow pustules (uredinia) form on floricanes in late spring. Buff-colored pustules (telia) develop among the uredinia on leaves in fall. This disease is commonly found in 'Oregon Thornless Evergreen'.
Symptoms: Canes become brittle and break easily. Premature defoliation can occur if disease pressure is severe.
Chemical control:
Apply as soon as canes are trellised.
Apply one of the following copper products at green tip stage and again just
before blossoms open.
Cultural control:
Cane Blight
Leptosphaeria coniothyrium
This fungal disease is seldom found blackberries but occasionally occurs in the hybrid berries, such as 'Boysenberry' and 'Loganberry'. This pathogen is a wound invader; wounds from the fruit-catching plates of mechanical harvesters result in primocane infections. Rain or overhead irrigation during harvest can increase disease incidence because spores are disseminated in splashing water.
Symptoms: The infected area flattens and may crack open. The blighted canes turn gray and often show black specks containing the fungal fruiting bodies (pycnidia). Diagnostic lesions are internal. Scrape the affected cane with a knife to expose vascular tissue. Healthy tissue should be moist and light green; the canker will be orangish red. Vascular discoloration generally extends above and below the external wound.
Chemical control:
Direct spray to the cane's base during or immediately after harvest or during
pruning.
Benomyl: Benlate 50 WP at 12 oz/A. Pest is not on the label, but Benlate is
highly effective. 3 day PHI. 24 hour REI.
Cultural control:
Cane and Crown Gall
Agrobacterium
tumefaciens and A. rubi
These bacteria may come into a planting with infected plants or persist in soil as a result of previously infected plants. Infection is through cane or crown injuries; mechanical injuries, such as those from pruning, training, and harvesting, favor the disease. Cane gall can occur from splits in the cane from bending and training the cane. The critical time to protect against crown gall is the first year after planting. Experimentally initiated infections during the first growing season after planting resulted in severe devitalization or death of the plants.
Symptoms: Crown gall appears on fruiting canes as small rough ridges
or elongated overgrowths of granular gall tissue. Galls frequently cause canes
to split open. Crown gall infections also may develop as irregular warty galls
at the canes' base or on roots. Small galls are easily confused with tissue
overgrowths caused by excessive callus formation at wound sites, particularly in
the process of rooting stem cuttings. Symptoms may not develop for over a year
if infection occurs when temperatures are below 59 oF.
Chemical
control:
Biological control:
Dipping the roots and crown area of blackberry
plants in commercial preparations of the bacterium A. radiobacter K84 or strain
K1026 before planting provided good protection for at least the first year, thus
helping the plants to become well established. Follow manufacturer's directions.
To be effective it must be applied a few hours after wounding.. Commercial
products include: Galltrol-A (12 hour REI) and Nogall (4 hour REI).
Cultural control:
Downy Mildew
Peronospora sparsa
This fungus overwinters primarily as a systemic infection of canes, crowns, roots, and buds. The disease cycle starts each spring with the production of infected shoots from infected root, crown, and cane buds. Unfolding leaves are invaded during warm, wet conditions. Secondary infections of flowers and developing berries during wet, warm weather are initiated from flowering to harvest primarily by conidia produced on diseased shoots. Diseased berries then become an important source of inoculum for new cycles of berry infection. After harvest, infection of developing primocanes lying on the ground continues by internal mycelial growth and spore infection.
Symptoms: In summer to autumn, small, conspicuous, irregularly shaped
patches appear on upper leaf surfaces, starting near the petiole then following
leaf veins. Patches are yellow initially, becoming a deep wine red with a
brownish edge and brownish discoloration near and alongside veins. Systemic
infection is indicated by red streaking on stems and petioles. The fungus
attacks fruits, sepals, and pedicels of 'Boysenberry', causing fruit to become
dry and shriveled (dry cell syndrome). Berries may split and appear to be two
berries on one pedicel.
Chemical control:
Cultural control:
Fruit Rot
Botrytis cinerea
This fungus enters the plant through the blossom and lies dormant until the fruit develops. It is most prevalent in fields with overhead set irrigation systems or where fruit is allowed to become ripe enough to be harvested mechanically. Good air drainage between plants and between rows is important to rapidly dry fruits and foliage after rain or irrigation.
Symptoms: Rotted fruit, usually with gray "fuzz"on the surface. The fungus may also attack senescent leaves and cause cane infections. Small, black, overwintering structures (sclerotia) may develop on any infected plant part.
Chemical control:
Apply the first spray at 10% bloom, a second
spray 10 days later. Another spray just before harvest may be needed if rainy
weather is expected. Alternate fungicides to delay or prevent buildup of
resistant fungi. Although Benlate (benomyl) and Rovral (iprodione) are
registered for fruit rot control, resistant isolates of Botrytis are widespread
even on wild plants that have never been sprayed with these products.
Cultural control:
Leaf and Cane Spot
Septoria rubi
This fungal disease prevalent in most blackberry fields. Minute, black, fruiting bodies (pycnidia) are formed within infected tissue, mature, and produce spores. Rain spreads spores. In winter, the sexual spore stage forms on old dead leaves and on infected canes. During the wet early spring, more spores are produced, and these cause many new infections.
Symptoms: Leaf spots vary from light to dark brown and are about 3mm in size. At first, they purplish in color then later turn brown. In older leaf spots, centers are whitish with brown to red borders. Infections on canes are similar to those on leaves but are elongated and generally inconspicuous.
Chemical control (for every-year fruiting fields):
1. Spray after
harvest.
2. Spray again in early October before heavy rains begin.
3. Spray again at budbreak in early March.
4. Spray young primocanes at 0 to 6 inches growth, 12- to 18-inch growth
and 2- to 3-foot growth.
Cultural control:
Orange Rust
Gymnoconia nitens
This fungus is systemic in an infected plant. It does not produce telia, and is referred to as a short-cycle form. Aeciospores that develop in the spring from this form develop systemic infections. This disease is not common but, due to its systemic nature, is serious once established.
Symptoms: Many weak, spindly shoots arise from infected roots and crowns in spring. Infected shoots may lack spines. Some primocanes and floricanes may look healthy later in the season, but floricanes never produce flowers due to systemic infection. In spring, unfolding leaves can be stunted, misshapen, and pale green to yellow. Lower leaf surfaces become covered with blisterlike pustules (aecia). Aecia are waxy at first, then turn a powdery bright, almost fluorescent orange.
Chemical control: (None will cure existing infections.)
Cultural control:
Powdery Mildew
Sphaerotheca
macularis
Blackberries usually are not affected by this fungal disease but 'Boysenberry' is very susceptible. Warm, dry weather favors development of this disease. In spring, ascospores are the primary inoculum. Conidia produced on the leaf surface of infected tissue serve as secondary inoculum for repeated cycles of infection throughout the growing season.
Symptoms: Whitish gray, powdery growth on foliage and fruit. Severe mildew retards, dwarfs, and distorts plant parts and makes fruit unsalable. Young fruits fail to size properly, wither, and die.
Chemical control:
Dormant spray.
Apply during the growing season when disease first appears. Repeat every 10
to 14 days as needed.
Biological control:
Cultural control:
Purple Blotch
Septocyta ruborum
A fungus similar to Septoria rubi. Spores are produced in spring on floricanes and infect only primocanes. Symptoms will not develop unless a chilling requirement is met.
Symptoms: Dark green, irregularly shaped lesions appear on canes late in the growing season. During winter and spring, lesions become purple with a red margin. Affected areas 0.5 to 2 inches long develop into cankers and girdle canes. Severely affected canes die in spring. Small, black, fruiting structures (pycnidia) are in the lesion's center. Leaf spots do not develop.
Cultural control:The disease has not been a problem in alternate-year
(AY) fields when canes are trained up as they grow. If canes are allowed to
lie on the ground, the disease can be just as severe as in fields where berries
are harvested annually.
Chemical control (for every-year fruiting fields):
1. Spray after harvest.
2. Spray again in early October before heavy rains begin.
3. Spray again at budbreak in early March.
4. Spray young primocanes at 0 to 6 inches growth, 12- to 18-inch growth and
2- to 3-foot growth.
Stamen Blight
Hapalosphaeria deformans
This fungal disease is severe in some plantings; severity varies markedly from year to year. Rain splashes spores from infected flowers to axillary buds of primocanes during bloom. The infection process is not well understood but occurs in summer.
Symptoms: Stamens of infected flowers are flattened against the petals instead of in an upright ring. Anthers are swollen, brown, and do not shed pollen. Since sporulation occurs before the flower opens, the flower has a white, powdery appearance when open. Flowers may have symptoms on sepals: leaflike structures at the tips and double the number of petals. Some species of blackberry may show a witches' broom of the inflorescences. If fruit develops, the receptacle is constricted, and a number of drupelets either fail to develop or do so unevenly. Ripening may be uneven, and fruit is hard and difficult to remove from the receptacle.
Chemical control:
Direct sprays onto primocanes in the every-year fruiting system any time between
flowering and harvest.
Captan 50 WP at 4 lb/A. Although this disease is not on the label, captan
has been shown to be effective. 3 day PHI. 4 day REI.
Cultural control:
The alternate-year fruiting system controls the disease by removing the inoculum source from above the developing primocanes.
Virus Diseases
Many viruses have been found in blackberries in the Pacific Northwest. Blackberry calico virus (a carlavirus) is universally present in older commercial 'Loganberry' fields. Similar calico diseases occur in 'Marion' and other blackberry cultivars. Other virus diseases known to infect blackberries in the Pacific Northwest include Tobacco streak virus (TSV), an ilarvirus transmitted by unknown means, and Raspberry bushy dwarf virus (RBDV), which is transmitted by pollen. Calico, Tobacco streak, and Raspberry bushy dwarf viruses can be detected serologically.
Symptoms: Usually no definite symptoms, except a decrease in vigor and yield. Raspberry bushy dwarf virus in 'Marion' causes bright yellowing of the leaves on primocanes and a bleaching of leaves on fruiting canes in July and August; RBDV can cause a 50% yield reduction and a 40% reduction in fruit size and drupelet number. Blackberry Calico is characterized by faint yellow blotches in leaves especially on fruiting canes. TSV causes reduced plant vigor.
Cultural control:
Nematodes
Nematodes are presently not considered a problem in blackberries (7).
Weeds
In a long-lived perennial crop like blackberries, control of weeds, especially perennial weeds, is critical prior to planting. In prospective fields, perennial weeds are treated with a systemic herbicide, such as glyphosate, prior to planting. This is usually done many weeks before anticipated planting date, which generally occurs in the spring. Control of annual weeds prior to planting is accomplished by disking the prospective field several times prior to planting, allowing annual weeds to germinate between disking. Several herbicides are registered for use in non-bearing blackberries, which provides additional options for weed control in newly planted fields if a crop won't be harvested for more than 365 days after application (15). Once planted, a new field will be treated with a preemergence herbicide. A second application of a preemergence herbicide is generally applied in the fall, prior to fall rains. In established fields, a preemergence herbicide is usually applied in spring, and again in fall. To create a vegetation-free zone in the plant row prior to the preemergence herbicide application, currently growing weeds are removed by hand hoeing or are treated with a contact herbicide, such as paraquat (Gramoxone) or pelargonic acid (Scythe). Treatment of row middles varies widely; middles are sometimes planted to a permanent sod and mowed, disked periodically throughout the growing season, or disked then treated with a preemergence herbicide in spring and fall. Approximately 80% of blackberry fields are treated with an herbicide (1).
New Plantings
Simazine
Formulation: Simazine 90 WDG or 90DF, Princep Caliber 90, Simazine 4L
Application Type and Timing: Preemergence. Apply in spring within 2 weeks after transplanting if soil is settled around plant roots. Apply before weeds are established
Rate: 1 to 1.6 lb ai/A
PHI: Unavailable
REI: 12 hours
Remarks: Requires sprinkler irrigation or rain to activate. Do not apply on sandy or gravelly soils.
Napropamide
Formulation: Devrinol 50DF
Application Type and Timing: Preemergence. Apply after transplanting to firm soil, before weeds germinate.
Rate: 4 lb ai/A
PHI: Unavailable
REI: 12 hours
Remarks: Water the day of treatment to wet the soil 2 to 4 inches deep to reduce degradation by sun and activate the herbicide. Where convenient, shallow mechanical incorporation appears to improve activation.
Oryzalin
Formulation: Surflan
Application Type and Timing: Apply after transplanting to firm soil before weeds germinate.
Rate: 2 to 6 lb ai/A
PHI: Unavailable
REI: 12 hours
Remarks: Do not allow transplant roots to contact treated soil. Requires sprinkler irrigation, rain, or shallow cultivation (1 to 2 inches) for activation.
Bentazon
Formulation: Basagran Herbicide
Application Type and Timing: Post-emergence. Apply before or at planting only.
Rate: 0.75 to 1 lb ai/A
PHI: 365 days
REI: 48 hours
Remarks: Non-bearing blackberries only. Use as a directed spray to actively growing weed foliage, coinciding with weed size as described on the label. Add 2 to 4 pints/A of a crop oil concentrate to enhance activity. Provides post-emergence control of broadleaf weeds such as, Canada thistle and yellow nutsedge. Two treatments applied 7 to 10 days apart may be required for Canada thistle or yellow nutsedge. Temperatures below 55°F, drought, or rain within 8 hours will reduce activity.
Isoxaben
Formulation: Gallery 75 Dry Flowable
Application Type and Timing: Preemergence. Apply after transplanting to firm soil, before weeds germinate.
Rate: 0.5 to1 lb ai/A
PHI: 365 days
REI: 12 hours
Remarks: Non-bearing blackberries only. Controls several broadleaf weeds; will not control grasses. Partially suppresses field bindweed and curly dock at the 1 lb ai/A rate. Requires sprinkler irrigation or rain (0.5 inch or more) for activation.
Fluazifop
Formulation: Fusilade DX
Application Type and Timing: Post-emergence. Apply to actively growing grasses, or within 7 days after irrigation, as a directed spray with 1% crop oil or 0.25% nonionic surfactant.
Rate: Consult label
PHI: 365 days
REI: 12 hours
Remarks: Non-bearing blackberries only. Controls grasses only; does not control broadleaf weeds. Identify grasses and adjust rates, depending on susceptibility and stage of weed growth, according to label instructions. Results often are erratic on grasses stressed from lack of vigor, drought, high temperature, or low fertility. More mature grasses and quackgrass can be controlled but may require two applications. Annual bluegrass and all fine fescues resist treatment.
Sethoxydim
Formulation: Poast
Application Type and Timing: Post-emergence. Apply to actively growing grass weeds.
Rate: 0.28 to 0.47 lb ai/A (1.5 to 2.5 pints Poast/A)
PHI: 45 days
REI: 12 hours
Remarks: Identify susceptible grasses and apply at optimum growth stage listed on the label; add 2 pints/A of a nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed from drought, high temperatures, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed. Do not exceed 5 pints product/A per season.
Clethodim
Formulation: Prism or Select
Application Type and Timing: Post-emergence. Apply to actively growing annual or perennial grasses as listed on label.
Rate: 0.094 to 0.125 lb ai/A (13 to 17 fl. oz. Prism/A or 6 to 8 fl. oz. Select/A)
PHI: 365 days
REI: 24 hours
Remarks: Non-bearing blackberries only. Controls grasses only; does not control broadleaf weeds.
Glyphosate
Formulation: Numerous product names.
Application Type and Timing: Post-emergence. Apply to actively growing weeds either as site preparation or as a directed spray in nonbearing crops 1 year before first harvest.
Rate: Consult label.
PHI: 365 days
REI: 4 hours
Remarks: Avoid contact with green foliage or suckers of the blackberry crop.
Established Plantings
Diuron
Formulation: Karmex, Diuron 80 or Diuron 4L.
Application Type and Timing: Preemergence. Apply in winter as single application or apply half-doses in October and March.
Rate: 1.6 to 2.4 lb ai/A
PHI: Unavailable.
REI: 12 hours
Remarks: Use on plants that have been established at least one year. Spray soil around base of plant, avoiding crop foliage. Do not use on plants being tip layered. To activate, irrigate after application or apply prior to a rain episode. Reduce rate or rotate to other herbicides after effective weed control is achieved. Sprinkler irrigate if applied before fall rains begin. Can be rotated with simazine or other herbicides (except terbacil) to reduce weed shifts.
Simazine
Formulation: Simazine 90 WDG or 90DF, Princep Caliber 90, Simazine 4L
Application Type and Timing: Preemergence. Apply in winter as single application or apply half-doses in October and March.
Apply before weeds are established
Rate: 1.6 to 4 lb ai/A
PHI: Unavailable
REI: 12 hours
Remarks: Requires sprinkler irrigation or rain to activate. Apply half rate on plants less than 6 months old. . Reduce rate or rotate with other herbicides after effective weed control is achieved. Can be rotated with diuron or other herbicides (except terbacil) to reduce weed shifts.
Terbacil
Formulation: Sinbar
Application Type and Timing: Preemergence. Apply in fall or early spring before fruit set while weeds are small.
Rate: 0.8 to 1.6 lb ai/A
PHI: 70 days
REI: 12 hours
Remarks: Apply higher rate on fine-textured soils or soils high in organic matter Sprinkler irrigate if rain does not follow application within 2 weeks. Reduce rates by as much as one-half or rotate with other herbicides after effective weed control is achieved.
Do not apply on gravelly soils or soils containing less than 1% organic matter, nor on weak plants or eroded areas with exposed roots. Avoid use for 2 years when replanting is anticipated. Can be rotated with diuron or other herbicides (except simazine) to reduce weed shifts.
Norflurazon
Formulation: Solicam
Rate: 2.5 to 5 Lb ai/A
Application Type and Timing: Preemergence. Apply from fall to early spring before weeds emerge and when crop is dormant.
PHI: Unavailable
REI: 12 hours
Remarks: The soil surface must be weed-free and relatively free of plant residues or debris. Apply only once per year. Temporary bleaching or chlorosis may occur.
Dichlobenil
Formulation: Casoron
Application Type and Timing: Preemergence. Apply midwinter immediately before a cold rain to reduce volatility and enhance weed suppression.
Rate: 4 lb ai/A (100 lb/A granular)
PHI: 30 days
REI: 12 hours
Remarks: Weigh and distribute uniformly exact quantities over precisely measured areas to ensure accurate applications. For 'Thornless Evergreen' blackberries, apply October through December 1, but never on light-texture, sandy soils.
Napropamide
Formulation: Devrinol
Application Type and Timing: Preemergence. Apply in fall through spring before weeds germinate.
Rate: 4 lb ai/A
PHI: Unavailable
REI: 12 hours
Remarks: Irrigation or shallow incorporation is recommended for treatments made November through February, if no rain falls within 2 weeks after application. Irrigate within 24 hours to wet soil 2 to 4 inches deep when applied March through October. Excessive plant residues on soil surface reduce performance.
Oryzalin
Formulation: Surflan
Application Type and Timing: Apply late fall or early spring to bare soil
Rate: 2 to 6 lb ai/A
PHI: Unavailable
REI: 12 hours
Remarks: Use higher rates or split treatments and apply in fall and spring for longer residual control. Irrigate with at least 0.5 inch water or rain to activate herbicide. Shallow cultivation can provide control of newly germinated weeds without reducing herbicide activity. Allow 24 months before planting vegetables following berries
Pronamide
Formulation: Kerb
Rate: 0.5 to 3 lb ai/A
Application Type and Timing: Preemergence. Apply in fall or winter, preferably October to December when ground is not frozen.
PHI: Unavailable
REI: 12 hours
Remarks: Use lower rates for annual grasses, higher rates for control of perennial grasses such as quackgrass. Requires moisture from rain or irrigation for activation. Use only in berries established at least 3 months. Degraded by microorganisms at higher temperatures. 24c registration. Restricted Use Pesticide.
Paraquat
Formulation: Gramoxone Extra or Gramoxone Max
Rate: Consult labels since formulations differ.
Application Type and Timing: Post-emergence. Apply late winter or early spring before new shoots emerge, or late summer or fall after training new canes. Avoid contacting blackberry foliage or canes.
PHI: Unavailable
REI: 12 hours
Remarks: Adjust spray volume to thoroughly wet weeds. Direct spray to targeted weeds. Add a nonionic surfactant or crop oil concentrate according to label specifications, taking care to avoid anionic formulations that react in the tank to form insoluble precipitates. Restricted Use Pesticide.
Glyphosate
Formulation: Numerous product names.
Application Type and Timing: Post-emergence. Apply to actively growing weeds
Rate: Consult label.
PHI: 14 days
REI: 4 hours
Remarks: Avoid contact with green foliage or suckers of the blackberry crop. Avoid treatments in late summer when sugars move toward the crown. Select application equipment to prevent crop injury by directing spray, or use low-pressure hand-held sprayers or selective applicators.
Sethoxydim
Formulation: Poast
Application Type and Timing: Post-emergence. Apply to actively growing grass weeds.
Rate: 0.28 to 0.47 lb ai/A (1.5 to 2.5 pints Poast/A)
PHI: 45 days
REI: 12 hours
Remarks: Identify susceptible grasses and apply at optimum growth stage listed on the label; add 2 pints/A of a nonphytotoxic crop oil concentrate to improve leaf absorption. Control often is erratic on grasses stunted or stressed from drought, high temperatures, or low fertility. Resistant grasses include annual bluegrass and all fine fescues, but quackgrass can be suppressed. Do not exceed 5 pints product/A per season.
Weed Control and Cane Suppression for Mechanical Harvesting
Pelargonic acid
Formulations: Scythe
Application Type and Timing: Post-emergence. Direct spray toward base of plants and apply when primocanes are less than 6 inches tall.
Rate: Use a 5 to 7% solution in 75 to 100 gallons/A water. For control of annual weeds, use a 3 to 5% solution.
PHI: Unavailable
REI: 12 hours
Remarks: Cool weather after treatment may slow activity and delay or reduce visible effects. Apply when temperatures are greater than 45°F. Adding a surfactant may enhance control.
Oxyfluorfen
Formulation: Goal 2XL or Galigan 2XL
Rate: 0.4 to 0.8 lb ai/A (1.6 to 3.2 pints product/A broadcast)
Application Type and Timing: Post-emergence. Apply in a band in the plant row, directed to the primocanes and the bottom 18 inches of the floricanes. Apply when primocanes are approximately 4 to 6 inches tall.
PHI: 15 days
REI: 24 hours
Remarks: Primocane suppression may last 3 to 6 weeks; adjust timing, rate, and number of applications according to plant vigor and desired degree of primocane suppression. Cool, overcast conditions may enhance activity or cause injury. Adding 2 pints 80% active nonionic surfactant per 100 gal spray solution is suggested. Follow calculations for banded applications. 24c registration.
Carfentrazone-ethyl
Formulation: Aim 40W
Rate: 0.05 to 0.1 lb ai/A.
Application Type and Timing: Post-emergence. Apply in a band in the plant row, directed to the primocanes and the bottom 18 inches of the floricanes. Apply when primocanes are approximately 4 to 6 inches tall.
PHI: 15 days
REI: 12 hours
Remarks: Apply in minimum of 40 gals water per broadcast acre. Can re-apply at 14 to 21 day intervals. Follow calculations for banded applications.
Contacts
Bill HekmanJoe DeFrancesco
Dept. of Entomology
Oregon State University
2046 Cordley Hall
Corvallis, OR 97331-2907
541/737-0718
defrancj@bcc.orst.edu
Jim Gill
NORPAC Foods
P.O. Box 458
Stayton, OR 97383-0458
503/291-1510
Diane Kaufman
OSU/North Willamette Research and Extension Center
15210 NE Miley Road
Aurora, OR 97002
503/678-1264 x23
Diane.Kaufman@orst.edu
Philip Gütt
Executive Director
Oregon Raspberry and Blackberry Commission
4845B SW Dresden
Corvallis, OR 97333
Bernadine Strik
Horticulture
Oregon State University
Corvallis, OR 97331
strikb@bcc.orst.edu
References
Acknowledgments
This crop profile was prepared by J. DeFrancesco, Department of Entomology, W. Parrott, and J. Jenkins, Agricultural Chemistry Extension, Department of Environmental and Molecular Toxicology, Oregon State University.