Plant Health Management for Backyard Bramble (Raspberry and Blackberry) Plantings

1. Plant Health Management for Backyard Bramble (Raspberry and Blackberry) Plantings

2. Prepared by Mike Ellis Professor and Extension Specialistand Omer Erincik Graduate Research Assistant Department of Plant Pathology The Ohio State University OARDC/OSUE Wooster, OH, 44691

3. Common Diseases on Fruit Gray mold(Botrytis fruit rot) Symptoms: • One to several blossoms in a cluster may show blasting (browning and drying). • Berries eventually become covered by a grayish, dusty, or powdery growth of the fungus.

4. Gray mold Disease Development: • Caused by the fungus Botrytis cinerea • Most infections occur during bloom; however, symptoms are usually not observed until harvest. • Temperatures between 70 and 80 °F and free moisture (water) on the foliage from rain, dew, fog, or irrigation are ideal conditions for disease development. • The disease is generally most severe in the interior areas of the plant canopy where humidity is higher and air movement is poor.

5. Management of gray mold • Free water (wet conditions) is required for most fungal pathogens to infect fruit. Any practice that promotes faster drying of fruit and foliage is beneficial for disease control. • Site selection • Select a site with good air movement and sun exposure (promote faster drying). • Canopy management • Prune to keep row width between 1 or 2 feet in order to encourage air movement and faster drying. • Control timing and amount of nitrogen fertilizer to prevent excessive growth.

6. Management of fruit rot diseases • Irrigation • If you use overhead irrigation irrigate early in the day, so that plants can dry faster. • Handling • Harvest mature fruit promptly to avoid letting berries become overripe • Pick fruit carefully, avoid bruising • Process and or refrigerate fruit immediately after harvest

7. Common cane diseases on brambles Anthracnose Cane blight Spur blight

8. Symptoms of cane diseases Anthracnose • Small purple spots develop on young canes. Eventually, they become grayish and sunken in the centers surrounded by a reddish margin. Cane blight • Brownish-purple to grayish areas, up to several inches long usually develop around pruning or other wounds. Branches suddenly wilt and die above the blighted area. Spur blight • Reddish-brown or purplish-brown areas up to several inches long develop at the nodes on the young canes. Eventually, the bark may split lengthwise in the diseased areas.

9. Cane diseases on brambles Disease Development: • Causal fungi (pathogens): Anthracnose……...Elsinoe veneta Cane blight……….Leptosphaeria coniothyrium Spur blight……….Didymella applanata • These three fungal pathogens survive over winter in spots or other infected areas on canes. • Spores of these pathogens spread to new canes during spring in splashing water from rain or overhead irrigation to cause new infections.

10. Management of brambles cane diseases • Use disease free planting stock • Proper site selection • Choose a site with good air circulation and sun exposure (promotes faster drying). • Pruning (sanitation) • Prune out all canes showing disease symptoms to reduce pathogen population • Remove infected canes from the planting • Canopy Management: • Avoid over fertilization, especially with nitrogen • Prune to keep row width between 1 to 2 feet to encourage rapid drying.

11. Common Diseases Attacking Roots Verticillium wilt Phytophthora root rot

12. Verticillium wilt Symptoms: • Starting at the base of the cane and processing upward, leaves wilt, turn yellow, and drop. • Black raspberry and blackberry canes may exhibit a blue color or purple streaking from the soil line extending up infected canes to varying heights.

13. Verticillium wilt Disease Development: • Caused by the soil-borne fungus, Verticillium albo-atrum • The fungus can survive in soil for many years. • The fungus infects roots and plugs water-conducting tissues (xylem). This prevents the movement of water from the roots to the rest of the plant; thus, the plant eventually wilts, and dies. • Disease is favored by wet and poorly drained soils.

14. Phytophthora root rot Symptoms: • Healthy canes may suddenly decline and collapse. • Leaves may initially take on a yellow, red, or orange color or may begin scorching along the edges. • Affected canes eventually wilt and die. • On the below-ground portion of the crown or large roots, a distinct line can generally be seen between healthy and infected tissues after scraping away the outer bark. Infected tissues are brown to brownish-red.

15. Phytophthora root rot Disease development: • caused by Phytophthora spp. • favored by high soil moisture (saturated soil) and cool temperatures. • infection can occur throughout the growing season if soil moisture conditions are favorable. • most destructive in heavy clay soils that are saturated with water during cool weather.

16. Management of root diseases • Use healthy planting stock • Proper site selection • Plant in well-drained soil • Select a site that does not have a previous history of problems with any of the root diseases. • Sanitation • Dig up diseased plants, including roots, and remove them from the planting.

17. Management of root diseases • Rotation • Do not replant brambles where disease has been a problem for at least 2 years. • Improve soil drainage Any practice that improves soil drainage is beneficial to control. • Plant on raised beds • Tile planting areas.

18. Management of root diseases • Use resistant varieties for Phytophthora root rot Phytophthora root rot is most destructive on red raspberries. Black raspberries are not immune but appear to be much more resistant than red raspberries. The disease is rare on blackberries. Although no red raspberry varieties are completely resistant, varieties vary greatly in their susceptibility. Choose red raspberry varieties with higher levels of resistance.

19. Diseases caused by rust fungi Orange rust Late leaf rust

20. Orange rust Symptoms: • The lower surface of infected leaves become covered with blister-like pustules. Eventually, the pustules turn into bright orange, powdery masses of spores. • Plants are systemically infected (fungus grows throughout the plant and the plant is infected for life). In years following infection, infected canes will be bushy and spindly as they emerge in the spring. • New leaves on infected canes are stunted or misshapen and pale-green to yellowish.

21. Orange rust Disease development: • Orange rust only affects black raspberry and blackberry. Red raspberries are immune. • In late May to early June, the bright orange spores of the pathogen spread from infected leaves to healthy leaves by the wind and perhaps rain-splash. • When environmental conditions favorable (temperatures between 43 and 72 °F and long period of wetness), the spores (aeciospores) germinate and penetrate the leaf causing localized infections.

22. Orange rust Disease development: • About 45 days later the fungus produces another type of spore (teliospores) in these infected areas. During late summer or early fall, these teliospores produce yet another type of spore (basidiospore). Basidiospores infect buds at the base of the plant to cause systemic infection. • The fungus becomes systemic, growing into the crown at the base of the infected shoots, and into newly formed roots.

23. Leaf late rust Symptoms: • Small chlorotic or yellow spots form on the upper leaf surface. • Small pustules filled with powdery spores are formed on the underside of the infected leaves. • These “rust” pustules also occur on fruit.

24. Leaf late rust Disease development • Pathogen: Pucciniastrum americanum • Disease only affects red raspberries. Black raspberries and blackberries are immune. • The small, numerous, light yellow spots seen on the undersurfaces of the leaves are the uredinial pustules that contain the urediniospores of the fungus. • These spores are capable of causing new infections on leaves and fruit throughout the growing season.

25. Management of rust diseases • Use healthy planting stock • Site selection • Select a site with good air movement and sun exposure (promote faster drying). • Canopy control • Prune to keep row width between 1 or 2 feet in order to encourage air movement and faster drying. • Control timing and amount of nitrogen fertilizer to prevent excessive growth. • Sanitation • Remove and destroy infected plants including the roots (important for orange rust). • Destroy nearby wild brambles that serve as a reservoir for disease.

26. Management of rust diseases • Disease resistance: Orange rust • Red raspberries are immune (completely resistant) • There are no resistant black raspberry varieties. Late leaf rust • Black raspberries and blackberries are immune. • No red raspberries varieties are resistant.

27. Using Fungicides For Brambles Disease Control • Fungicides can be important for disease control in commercial plantings; however, fungicides are generally not recommended for use in backyard bramble plantings. • Effective fungicides are usually difficult or impossible for backyard growers to obtain. • If not used properly, they are generally not effective.

28. For backyard growers that do wish to use fungicides in the disease management program, fungicide recommendations are available for brambles in Bulletin 780 “Controlling Disease and insects In Home Fruit Planting”.

29. Emphasis for disease control in backyard plantings should be placed on: • Use of the various cultural practices for disease control mentioned previously. • Use of disease resistant varieties when possible.

30. Selected literature for backyard fruit production and plant health management: • Bulletin 591. “Growing and Using Fruit at Home” • Bulletin 780. “Controlling Diseases and Insects in Home Fruit Planting” • Bulletin 782. “Brambles Production Management and Marketing”. • Bulletin 861.“Midwest Small Fruit Pest Management Handbook”. These can be obtained through your county extension agent or the Extension Publications Office, The Ohio State University, 385 Kottman Hall, 2021 Coffey Road, Columbus, Ohio, 43210-1044

31. To get more information about plant diseases visit the websites below. http://www.ag.ohio- state.edu/~plantdoc/extension.php http://www.ohioline.ag.ohio-state.edu