syringaeand is a problem in production areas west of the Cascade Mountains. Cane diseases can infect red raspberry, black raspberry and blackberry. Make sure canes are thoroughly covered. is caused by a soil-inhabiting bacterium. In this trial, both of the treatments that included ProPhyt applications in 2018 resulted in a numerical reduction in algal spot number and algal spot diameter relative to the untreated control; however, additional applications of ProPhyt in 2019 did not have a significant impact on OCB in terms of either spot number or diameter on floricanes. Fungicide availability, labels, and recommended rates change frequently and vary between states and localities. 2019. A definitive diagnosis is important because late frosts, powdery mildew, mite injury, fungicide and herbicide sprays and boron deficiency can cause the same symptoms. All symptoms of cane blight occur in close association with wounds. Consult the ManKocide label for specific rates and timing of application by crop. Consider including captan in tank mixtures for resistance management. Hemphill, W.H. ManKocide is also labeled for Frost Injury Protection. It seems to be most severe when drought stress occurs after widespread infections take place. Can be used day of harvest. of Ag., Bugwood.org. Some cane disease fungi survive on wild Rubus spp. Plant Dis. You’ll do best to start a defense against cane blight early by adopting good cultural practices. Some brands labeled for delayed dormant and/or growing season applications for scab and powdery mildew of apple; anthracnose, rust and powdery mildew of blackberry; and powdery mildew and scab on pear. Therefore, it was formerly assumed that infection of primocanes took place throughout the summer and fall, with subsequent infections of these canes (now floricanes) taking place in the spring. Specific fungicide sprays are usually not needed in the home garden planting where good sanitation is practiced, except when the harvest period is wet. PDMR. Natural Control. Evaluation of late-season and early-season applications of potassium phosphite for management of orange cane blotch on blackberry floricanes in Georgia, 2019. Canes are usually brittle at the point of infection, and may break if bent. 13:PF010. Symptoms appear on canes and leaves. The rows adjacent to the test plots served as buffer rows, and phosphonate fungicides were not applied to these rows for the duration of the experiment. Crown gall bacteria need fresh wounds to cause an infection, which can be caused by transplanting and cultivating activities, feeding damage from nematodes or soil insects. If crown gall symptoms are already present on existing plants consider the selection of other nonsusceptible plant material. Cane blight usually affects only canes that have been wounded in their vegetative year. Among the diseases affecting blackberry production in the southeastern U.S., one of the more unusual disease issues is orange cane blotch (OCB). Remove and destroy infected canes. Treatments were applied to a randomized complete block design. Evaluation of early-season, late-season, and long-season applications of potassium phosphite for management of orange cane blotch on blackberry primocanes in Georgia, 2019. Crown gall bacteria can be present in the soil, on contaminated tools or carried by water to susceptible host plants. 2020a). Cane blight occasionally impacts homegrown and commercial raspberries and blackberries in Kentucky. 82:263-263. All symptoms of cane blight occur in close association with wounds. Crown gall will occasionally infect brambles as the disease has a wide host range. Early orange felt symptoms on blackberry cane are yellowish spots on the canes. Most fungicides are utilized on a 7- to 14-day spraying schedule. Removal of galls will not cure infected plants because bacterial genes already inserted into the host's cells will continue to transform additional cells throughout the plant and produce galls in other locations. Cane Borer. 12-hr reentry. Often first noticed when leaves wilt and wither. On overwintering red raspberry canes, spur blight appears as purple to brown cankers below the buds. In the second trial, spots were assessed on floricanes in the spring of 2019 (Hemphill et al. Orange blotches produced by this disease are usually first observed on primocanes in the late summer and fall. Spores germinate in wounds and produce new infections. The disease causes lesions to develop on both primocanes (current-year canes) and floricanes (second-year or fruiting canes) and can result in reduced yield and cane death. Crop Protect. By Jonathan E. Oliver, Will H. Hemphill, and Phillip M. Brannen, Department of Plant Pathology, University of Georgia. It is caused by a soil-inhabiting bacterium, Agrobacterium tumeafaciens, which occurs worldwide and attacks over 600 plant species in more than 90 plant families. Removal of infected plants will lower bacterial populations in the soil, however, low populations of soil bacteria still persist as surface colonies on many plant species regardless of their susceptibility to crown gall. Photo: Blackberry Tobacco Ringspot VirusJohn Fisher, Ohio Dept. Treatments consisted of: (1) ProPhyt applications in 2018 and 2019, (2) ProPhyt applications in 2018 only, (3) ProPhyt applications in 2019 only, and (4) an untreated control. 2020b). One of the few diseases that can completely destroy a plant, cane blight mainly enters through pruning wounds or injured canes. On overwintering red raspberry canes, spur blight appears as purple to brown cankers below the buds. During the growing season used for powdery mildew Anthracnose appears on most raspberries as gray spots or irregular cankers on the lower stems. Symptoms of cane blight can include dark red or purple lesions on the plant. Berry size and cane growth, by contrast, do not appear to be significantly impacted by OCB. Photo: Blackberry crown gall, Eric Coombs, OregonDept. Yield Response to Orange Cane Blotch of Blackberry Grown in the Georgia Coastal Plain. 2019b). Characteristic symptoms are the development of spindly, thornless canes (on normally thorny cultivars) and the appearance of bright orange pustules on the undersides of leaves. 1998. Browne, F. B., Brannen, P. M., Scherm, H., Richardson, E. A., and Taylor, J.R. 2020. Treatments consisted of untreated control plants or plants treated with potassium phosphite (ProPhyt; Luxembourg Chemical) applied at 4 pts/A. These three diseases can be controlled routinely with good sanitation and one early season lime sulfur treatment before new growth begins. Black specks, which are reproductive bodies of the cane blight fungus, develop in the brown cankered bark. Furthermore, since OCB spots do not become apparent on new primocanes until the fall, growers have tended to begin chemical applications in the fall, after OCB spots become obvious; however, the optimal timing of potassium phosphite applications has not been examined previously in a comprehensive manner. Crown gall bacteria can be present in the soil, on contaminated tools or carried by water to susceptible host plants. 2) Gray mold (Botrytis) infected blackberry PDMR. By contrast, phosphonate fungicides (including potassium phosphite) have been shown to reduce the severity of OCB in blackberries (Browne et al. Auburn University – Clemson University – LSU AgCenter – Mississippi State University – NC State University – The University of Arkansas – The University of Georgia – The University of Tennessee – Virginia Polytechnic Institute and State University, Box 7601 – North Carolina State University – Raleigh, North Carolina 27695-7601 In particular, cane blight and Botryosphaeria-related diseases have been more frequently observed to cause problems in blackberry plantings where severe problems with OCB have been noted. 1998), and it has since become a prevalent issue in many blackberry production sites throughout the Coastal Plain region of the southeastern U.S. Furthermore, while yield impacts resulting from OCB disease were initially not clear, recent research at the University of Georgia has now shown that OCB can significantly reduce blackberry yield. Cane blight is one of the main blackberry diseases in the Southeast. ___________________________________________________________________________, Spray Schedule: General Disease and Insect Pest Control Recommendations, Home Fruit Preventative Spray Schedule and Management of Common Problems, 1) Anthracnose, cane blight, and spur blight (stem cankers). The bark in badly ca… Another name for this disease, orange felt, reflects the fact that these blotches sometimes take on the appearance of an orange felt-like material on the surface of the cane (Figure 1B). Improve air circulation by thinning healthy canes in the rows and keeping the planting free of weeds. With proper pruning and use of fungicides, blackberries can be produced without caneblight, even in wet years (Figure 7). This disease is caused by the bacterium Pseudomonas syringae pv. Hemphill, W., Oliver, J.E., Brannen, P. 2020a. Cause large brown dead areas (cankers). On first-year canes (primocanes) dark brown-to-purplish cankers form on new canes near the end of the season where pruning, insect, and other wounds are present. Apply a fungicide spray to the plants to protect against additional infections. Plant Health Prog. Adult is a long-horned beetle. Enters through wounds made by insects or mechanically. Cane Blight – This disease is caused by the fungus, Leptosphaeria coniothyrium, which sporadically attacks canes of all Rubus species. Hemphill, W., Oliver, J.E., & Brannen, P. 2020b. Anthracnose first appears in the spring on the young shoots as small, purplish, slightly raised or sunken spots. In sites with a history of issues with OCB, it is suggested that applications should be made approximately 3-4 weeks apart for a total of six applications. Based on this observational work, it is believed that the timings of key events in the disease cycle of OCB in southern Georgia are as follows: Unfortunately, cultural control measures alone are typically not sufficient to control OCB on blackberry in the southeastern U. S. Nonetheless, for optimal OCB management, the following practices are recommended (Brannen 2018): While copper products are effective for controlling other algal diseases, these products have not been found to be effective versus OCB in Georgia blackberry production. Copper type fungicides are recommended for control. Evaluation of Algicides for Management of Orange Felt and Fungicides for Control of Cane Blight Diseases of Blackberry – Phil Brannen (University of Georgia), $2,632 Developing the Genomic Infrastructure for Breeding Improved Black Raspberries – Chad E. Finn, Nahla V. Bassil, Jungmin Lee, and Jill Bushrakra (USDA-ARS, Corvallis, OR), $1,500 Characteristic symptoms are the development of spindly, thornless canes (on normally thorny cultivars) and the appearance of bright orange pustules on the undersides of leaves. Within an area of interest consisting of the bottom 2.5 ft from the crown, disease severity in the treated versus untreated plants was assessed in terms of relative algal spot size (spot diameter in mm) and number of algal spots per cane. Cane blight appears only on fruiting canes; infection occurs on primocanes near the end of the growing season. leaf curl and shot-hole of peach and cane blight and leaf spot of brambles. University of Georgia Cooperative Extension Circular 892. The cankers may encircle the cane, sometimes causing the death of the cane beyond the canker. Cane blight shows as dark-brown to purple, sunken cankers with dark margins near pruning cuts or wounds. The most obvious symptoms are the galls or growths that usually occur on the twigs, stems, and roots near the base of the plant at the soil line. PDMR. Typically, the orange disk-shaped blotches are more prevalent near the base of the affected cane, and these blotches may coalesce to cover virtually the entire cane surface under conditions favorable for disease development (wet, humid conditions). While most plant diseases are caused by fungal, bacterial, viral, or oomycete pathogens, OCB disease of blackberry is caused by a parasitic algal species, Cephaleuros virescens (Brannen 2018). All Rights Reserved.The University of Georgia is an Equal Opportunity, Affirmative Action, Veteran, Disability Institution.Privacy Policy, A website from the College of Agricultural and Environmental Sciences, Botrytis Sampling for Fungicide Resistance Development, Considerations for the Future of Anthracnose Disease Management in Strawberries, Virginia Polytechnic Institute and State University, College of Agricultural and Environmental Sciences, Primocanes infected during the previous season (now called. Treatments were applied to a randomized complete block design. It may attack black raspberry at points where canes have been snapped off or pruned to force lateral growth. Treatments were assigned using a split plot design, with 2018 treatments (sprayed or not sprayed) representing the main plot and 2019 treatments (sprayed or not sprayed) representing the sub plots. Anthracnose appears on most raspberries as gray spots or irregular cankers on the lower stems. Infected areas are bro… 2019a. Department of Plant Pathology, University of Georgia, Tifton, GA. Holcomb, G. E., Vann, S. R., and Buckley, J. The same fungus that causes gray mold on strawberries causes gray mold on bramble crops. For additional disease control recommendations for conventional blackberry production, please see the Southeast Regional Caneberries Integrated Management Guide (at www.smallfruits.org). Contact your local county agent for specific chemicalrecommendations. Superficially, insomuch as they are orange, these spots may resemble pustules caused by rust fungi; however, these felt-like blotches do not readily “rub off” or stain surfaces like the spores produced within a rust pustule (Brannen 2018). It can cause some damage to red raspberries as well. Cane blight shows as dark-brown to purple, sunken cankers with dark margins near pruning cuts or wounds. To prevent the spread of the fungus, remove plants showing symptoms before the spore pustules mature and rupture. Gall size can vary from small to large and are usually spongy when young, but the become hard and woody with age. The sores often form at places where the branch had been wounded. infected rosettes and blossom clusters should be Prune and burn fruiting canes immediately after harvest. In the spring, buds fail to break dormancy, lateral shoots wilt, or fruiting canes die when the fruit begins to ripen. Cane Blight of Blackberry Phillip M. Brannen, University of Georgia Extension Plant Pathologist Gerard Krewer, University of Georgia Extension Horticulturist Cane blight can be a major disease of blackberry in the Southeast, resulting in severe losses — sometimes causing the complete destruction of fruiting canes in any given year. 122:112-117. 104(1):161–167. Hemphill, W., Oliver, J.E., Brannen, P. 2020a. Cane blight and spur blight can cause significant damage to … Treatments were applied until runoff (equivalent to 50 gal water/A) using a backpack sprayer with a yellow poly flat fan tip (0.15 gpm, 30 degree angle). Dead cane blight infected canes look silvery grey … REC, Western Maryland 122:112-117. Managing Blackberry Harvest and Health in the Midst of a Rainy and Cool Season UPDATED 7/11/13. Gall size can vary from small to large and are usually spongy when young, but the become hard and woody with age. Evaluation of disinfectants, algicides, and fungicides for control of orange cane blotch of blackberry in the field. Group 3 + 11 fungicide. Spots can merge to cover entire portions of canes. Symptoms appear late in the season on new shoots where plants have been pruned. Cane blight Leaf spots Spur blight copper (M1) ChampWG Kocide 3000 Kocide 2000 Cuprofix Disperss Cuprofix Ultra 40 Disperss 2-3 lb 0.8-1.3 lb 1.5-2.3 lb 2.5-5 lb 1.25-2.5 lb See labels 1-2 1-2 1-2 0.5 0.5 Anthracnose Cane blight Leaf spots Orange cane blotch Spur blight myclobutanil (3) Rally 40WSP 1.25-3 oz 10 oz 0 Powdery mildew Rusts As orange blotches develop, they can often result in cracking of the cane surface (Figure 1C). Control of cane blight is the same as for anthracnose or spur blight. Please consult the various labels for rates, other recommendations, and precautions. The disease causes lesions to develop on both primocanes (current-year canes) and floricanes (second-year or fruiting canes) and can result in reduced yield and cane death. 20:67-69. Orange rust occurs only on black raspberry and blackberry (red raspberry is immune) and is caused by a fungus that develops systemically through the plant long before symptoms appear. Orange cane blotch of commercial blackberry in the southeastern United States. Botrytis blight is a fungal disease that infects blackberry bushes when the outdoor temperature is approximately 60 degrees F, and the weather is cold and rainy. Cane diseases of blackberry: identification of causal agents and modifications of management recommendations for cane blight and orange cane blotch. REC, General Disease and Insect Pest Control Recommendations. May be applied up to the day of harvest. Problem: Botryosphaeria Cane Canker of Blackberry Affected Area: The disease affects the branches Description: Sores appear around the buds on the main stems and are recognized by their red/brown discolorations. OCB disease of blackberry was first reported in Arkansas in 1997 (Holcomb et al. Viruses can cause a wide variety of symptoms including mottling, cupping, blistering, and yellow spotting of leaves. Orange felt (orange cane blotch) of blackberry. Apply fungicides after pruning each day to provide a protective barrier on the wound site untilhealing can occur. All cultural practices at each location throughout the trial were consistent with blackberry production methods commonly observed in the Southeast. (See Photo of Algal Spot) Anthracnose (fungus – Elsinoe veneta): A common cane and foliage disease of blackberry and dewberry sometimes called dieback. commonly sold for blackberry propagation. In particular, canes with larger and more numerous orange blotches were shown to produce significantly fewer berries than canes with little/no OCB blotches (Browne et al. In southern Georgia, this would correspond to beginning applications in approximately early- to mid-May. In the first trial, spots were assessed on primocanes in the fall of 2018 (Hemphill et al. Pruning wounds are the most common site of infection, but all types of … If crown gall symptoms are already present on existing plants consider the selection of other nonsusceptible plant material. 2020; Hemphill 2019). After tipping, apply a preventative fungicide to protect cuts from cane blight. These bacteria can also survive in contaminated soil for years without a susceptible host. Circular, light gray spots form on canes; as the disease progresses the spots become sunken with a dark purple margin. Evaluation of disinfectants, algicides, and fungicides for control of orange cane blotch of blackberry in the field. Photo: Anthracnose (raspberry)John Hartman, University of Kentucky, Bugwood.org, Photo: Bramble spur blight, MaryAnn Hansen, VA Polytechnic Ins.and State University, Bugwood.org. Cane Blight Facts Hemphill, W., Brannen, P., & Oliver, J.E. The only control for this disease is complete removal of the entire plant (including the roots) early in the season. The cracking and wounding caused by OCB is believed to allow for the entry of additional disease-causing organisms. However, recent field observational research at the University of Georgia strongly suggests that this disease is monocyclic (has only one infection cycle per year), with this alga only infecting new primocanes during one period in the late spring and early summer (Hemphill 2019). 'Boysenberry', 'Loganberry', and 'Youngberry' canes are seldom infected with cane blight unless canes first are frozen, pruned, or mechanically damaged. Previous trial work, however, did not specify whether potassium phosphite reduces OCB severity by reducing the number of spots (initial infections) or by reducing the size of spots (expansion after infection) on canes of infected blackberry. Leaf spots start off yellow, turn grey with a purple border and eventually dry up and drop out, resulting in shot holes. Cane blight occasionally impacts homegrown and commercial raspberries and blackberries in Kentucky. … B. In the spring, spores (both ascospores and conidia) are released from mature fruiting bodies in wet weather and dispersed by splashing rain or irrigation. Spectracide Immunox Multi-Purpose Fungicide Spray Concentrate for Gardens at 0.67 fl oz/gal water. We embody the University's land-grant mission with a commitment to eliminate hunger, preserve our natural resources, improve quality of life, and empower the next generation through world-class education. Timely fungicide sprays for control of anthracnose will reduce the number of new infections. Larvae indicated by sawdust. 2019a,b; Browne et al. Pre-harvest Interval (PHI): Zero (0) days Treatment: ManKocide may be applied as an aerial, ground dilute or ground concentrate spray unless specifically directed otherwise in the specific crop use directions. Thesis. Other Control Options. Furthermore, all blotches present on primocanes by the end of the season can be traced back to tiny red spots which appear during June and July, suggesting that virtually all new infections are occurring prior to fall (and are apparently a result of the observed algal reproduction in late-May to mid-July) (Figure 2). Both current and second-year canes can be affected. In this trial, ProPhyt applications reduced both algal spot number and algal spot diameter on primocanes relative to the untreated control treatment, suggesting that ProPhyt may act to limit both the infection of new primocanes as well as the expansion of algal spots after infection. Orange rust occurs only on black raspberry and blackberry (red raspberry is immune) and is caused by a fungus that develops systemically through the plant long before symptoms appear. Fungicide Resistance Management In the third trial, spots were assessed on primocanes in the fall of 2019 (Hemphill et al. Each of the three trials was replicated in each of three plantings in Lanier and Irwin counties in Georgia. The fungus Didymella applanata causes spur blight, a disease that commonly occurs together with cane blight. The Cane Blight of Blackberry factsheet contains more information about this disease. M.S. Two plantings were located in Irwin County (blackberry cultivar ‘Ouachita’) and one planting was located in Lanier County (blackberry cultivar ‘Osage’). The most obvious symptoms are the galls or growths that usually occur on the twigs, stems, and roots near the base of the plant at the soil line. Plant Dis. These are three fungal diseases that cause cankers on bramble canes, making them less vigorous and, in some cases, causing their death. This is mostly due to the wet, humid weather conditions in the region. These are often seen in young growth and can disappear later during hot weather. Browne, F. B., Brannen, P. M., Scherm, H., Brewer, M. T., Wilde, S. B., and Richardson, E. A. Bloom (Early + Full): Same options as above for rusts, leaf spots, anthracose, and cane blight. Cane blight is a fungal disease that affects the health of canes (i.e., stems) of cultivated and wild Rubus species (e.g., raspberries and blackberries), wherever they are grown. Phone: 919-515-6963, Please direct comments or suggestions to: Information Technology Manager, The University of Georgia College of Agricultural and Environmental Sciences © 2012-2020. Anthracnose is most severe in black raspberries. These bacteria can also survive in contaminated soil for years without a susceptible host. In wet weather, large numbers of microscopic spores ooze out of the pycnidia. The fungus overwinters in infected canes and on pruned cane stubs. Crop Protect. Cane blight infects first year canes through wounds and grows into the vascular system. To assess both the impact of potassium phosphite on OCB development and the effect that application timing has on OCB control, a series of three field trials were carried out in 2018 and 2019 in commercial blackberry plantings in southern Georgia. ... Phosphonate fungicides are the only ones which consistently suppress this disease on blackberries. It’s a disease that attacks all kinds of cane plants including black, purple and red raspberries. Fungicides are available; however, sanitation is a critical step in prevention and management. The spots are often so close together on black and purple raspberries that they form large irregular areas (cankers). If your raspberry bush buds die, the side shoots wilt and the canes fail, cane blight is probably the culprit. *Some fungicides may not provide “Excellent/+++++” control if population is resistant. 2019). These three diseases can be controlled routinely with good sanitation and one early season lime sulfur treatment before new growth begins. Though, in most cases, this disease does not limit blackberry production, recent research has elucidated the impacts of this disease on blackberry yield, the details of the disease cycle, and the options for effective chemical management (Browne et al. Efficacy of potassium phosphite for control of orange cane blotch of blackberry in Georgia, 2018. Bacterial canker can be particularly severe on young plants in new plantings because a high proportion of the wood is succulent and susceptible to disease. This ooze gives the bark a … are three fungal diseases that cause cankers on bramble canes, making them less vigorous and, in some cases, causing their death. What is cane blight? Anthracnose, Spur blight, Cane blight FUNGICIDE: liquid lime-sulfur OR Bordeaux (Cuprofix Disperss) 6 to 12 gal 5 to 6 lb This is an important spray for good disease control. Brannen, P. 2018. Crown gall bacteria need fresh wounds to cause an infection, which can be caused by transplanting and cultivating activities, feeding damage from nematodes or soil insects. Based upon the results of these trials, it is currently recommended that growers begin applications of potassium phosphite in the late spring, following the emergence of primocanes and immediately prior to the algal sporulation period. 2020). The infected part is not usually killed. Red raspberries are more susceptible to spur blight than purple or black raspberries. Black and purple raspberries appear to be more susceptible to cane blight than red raspberries, but all commonly cultivated raspberry cultivars can get the disease. Fungicides are available; however, sanitation is a critical step in prevention and management. The only control for this disease is complete removal of the entire plant (including the roots) early in the season. Central Maryland Do not use within 30 days of harvest. In fact, the orange blotches of OCB are actually pigmented algal filaments and reproductive structures (Holcomb et al. 14:PF069. First report of Cephaleuros virescens in Arkansas and its occurrence on cultivated blackberry in Arkansas and Louisiana. Later, they enlarge and become ash gray in the center with slightly raised purple margins. Trial 2: Spring applications of potassium phosphite do not significantly impact blotch number or blotch size on floricanes infected during the previous season. Consult County Extension Agent; Cane Blight. Tipped canes will grow stout and be more capable of supporting a heavy fruit crop the following year. The cankers enlarge and extend down the cane or encircle it, causing lateral shoots above the diseased area to wilt and eventually die. Raspberry crown borer INSECTICIDE: bifenthrin, MOA 3A (Brigade WSB) MOA 3A malathion, MOA 1B (Malathion 57EC) 16 oz 3 pt The beginning of early-season to mid-season applications coincided with primocane emergence, and the beginning of the mid-season to late-season applications coincided with algal sporulation on floricanes. Cane blight shows as dark-brown to purple, sunken cankers with dark margins near pruning cuts or wounds. Cane Blight. H; Tanos at 8 to 10 oz/A plus a copper-based fungicide. ... the smaller the diameter of the cane at pinching will minimize the potential for cane blight infection. If your blackberry plants have been affected by cane rust in the past, spray fungicides to reduce vulnerability. 2019. Trial 1: Potassium phosphite limits the infection of new primocanes as well as the expansion of algal spots after infection. of Ag., Bugwood.org. Removal of galls will not cure infected plants because bacterial genes already inserted into the host's cells will continue to transform additional cells throughout the plant and produce galls in other locations. In this trial, all ProPhyt treatments resulted in a significant reduction in spot number and diameter relative to the untreated control; however, the mid-season to late-season and long-season applications resulted in significantly smaller spots versus the early-season to mid-season applications of ProPhyt. 1998). Cankers form on the cane, often at the nodes, and extend down or … 14:PF031. Group 3 fungicide. Infection occurs in late spring or early summer through pruning and insect wounds. Treatments consisted of early-season to mid-season ProPhyt applications, mid-season to late-season ProPhyt applications, long-season ProPhyt applications, and an untreated control. and other woody plants. This disease has not been studied in detail, especially relating to overall damage. Cane blight may weaken fruiting canes of red raspberry. REC, Lower Eastern Shore Browne, F. B., Brannen, P. M., Scherm, H., Taylor, J. R., Shealey, J. S., Fall, L. A., and Beasley, E. D. 2019b. Removal of infected plants will lower bacterial populations in the soil, however, low populations of soil bacteria still persist as surface colonies on many plant species regardless of their susceptibility to crown gall. If you have to use a pruners, a fungicide should be applied soon after the canes were cut. Microscopy, combined with biweekly photography of blackberry canes, indicates that algal reproductive structures (sporangiophores containing zoospores) are produced on floricanes only in late-May to mid-July in southern Georgia. As the name of this disease indicates, the most readily observable symptom of OCB is the presence of orange-to-yellow blotches (or spots) on the canes of infected blackberry plants (Figure 1A). Trial 3: Both early-season to mid-season and mid-season to late-season applications of potassium phosphite can limit the infection of new primocanes, while mid-season to late-season applications can more effectively limit the expansion of algal spots after infection.