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 â 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 â¦ 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. â¦ 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. Itâs 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 âExcellent/+++++â 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 â¦ 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 â¦ 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.