Fact Sheet FS1372
Figure 1. Elderberry flowers.
Elderberry (Sambucus spp.) is a group of flowering woody perennial shrubs native to both Europe and Midwestern/Eastern North America. The European species (Sambucus nigra) is grown for commercial production in Europe. It is noted for its large, aromatic, and sweet, musky flowers, known as cymes, and flavorful clusters of berries, known as drupes, and a tree-like growth habit. The American elderberry (Sambucus canadensis), which tends to have more of a shrub-like growth habit, can be found growing from as far south as Florida to as far north as Quebec. The American species has slightly smaller, but more aromatic and sweeter flowers and berries than its European cousin. Both still have unrealized potential to be utilized in commercial production. Elderberry species vary in the toxicity of their fresh fruit. The American elderberry presents a low toxicity risk, but other North American species are available through nurseries and can be much more toxic. Traditionally European elderberries are processed by cooking or other heat processing to eliminate the toxic potential of their fruit. In addition, the American elderberry is better adapted to growing conditions in the Northeastern United States than the European elderberry. Thus, the focus of this factsheet is on the viability of American elderberry in commercial or niche crop production.
Elderberry is cultivated for its flowers and berries which are utilized in many different products including cordials, wines, jams, and teas. Elderberries are rich in vitamins A and C, minerals such as phosphorous, potassium, iron, and anthocyanins with high antioxidant activity. The U.S. elderberry market is expected to grow, as the popularity of this low-input crop continues to rise. With suitable growing conditions in New Jersey and access to diverse markets, elderberry may offer commercial growers an opportunity to expand into this new crop.
This fact sheet provides background on how to establish, maintain, and harvest an elderberry planting. In addition, it provides an overview of potential insect pests, diseases, and mammals associated with elderberry production.
Production Requirements
Site Selection
Elderberries will tolerate a wide range of soil textures and fertility, but growers should obtain the best yields from plants grown in moist, but well-drained soils. If possible, elderberry should be planted in full sun away from forest edges for best yields. This may also reduce losses via depredation by birds and will assist with pollination and disease prevention through good air circulation. Avoid planting elderberry where strawberries, mint, alfalfa, potatoes or tomatoes are grown to avoid verticillium wilt.
Figure 2. Elderberry fruit.
Plant Material Selection
The American elderberry was traditionally harvested from the wild, until improved cultivars were introduced several decades ago by the New York Agricultural Experiment Station and Agri-Food Canada in Nova Scotia ('Adams I', 'Adams II', 'Johns', 'York', 'Nova'). Cultivar development continues in several locations in North America including Canada, New York, and Missouri. Improved cultivars offer growers both higher yields and higher quality products, so they should be the foundation of all commercial plantings.
Elderberry pollination remains poorly understood. Flowers are wind pollinated, and fruit yields have been observed to be enhanced by cross pollination. Therefore, it is highly advisable to plant at least two cultivars within 60 feet of each other.
Planting Requirements
Growers can choose to purchase either potted plants or bare root plants from nurseries. Potted elderberries typically have a higher survival rate and come into full production sooner than bare root plants and begin producing a crop as early as the second year after planting. Throughout the first year of growth flower heads should be removed to ensure the plant utilizes its resources for root and shoot growth and establishment.
To enhance planting success, elderberries should be planted in the spring or fall. Spacing can range from 2 to 12 feet between plants, and 10 to 12 feet between rows. Wider spacing will delay filling the space but will allow the plants to have room to grow, which will ultimately result in greater yields, as well as improved air-circulation to help reduce fungal disease problems. After 2 to 3 years, the rows will fill in as the plants develop.
Figure 3. Elderberry shrub.
If growers choose to plant bare root plants, they should be planted in a 6- to 8-inch furrow, taking care to ensure the roots are buried at least 2 inches deep. Before planting, the canes should be cut back to 8 to 10 inches high. They should be planted with the lowest branch at or just below the soil line.
After planting the elderberries, the rows should be mulched with 3 to 4 inches of organic mulch, making sure to keep the mulch off the base of the plants. Collapsing mulches will reduce the attractiveness of the area as habitat for voles and other rodents. The alleys or middles between the rows should be sown with a cover crop of a mix of slow-growing grasses, such as tall fescue, hard fescue, dwarf perennial rye grass, or white clover. Monitor weeds closely and be careful not to damage the elderberries' shallow root system when cultivating or applying any chemical herbicides.
Irrigation Requirements
The roots of elderberry are shallow and mat-like, which means it is critical for the upper 3 to 4 inches of soil to provide adequate moisture. They should be thoroughly watered after they are planted, and subsequently watered 1 to 2 inches per week, when rainfall is not adequate. The addition of mulch and compost also helps in keeping the root systems moist. Overhead irrigation should be avoided if possible as this can greatly increase the occurrence of foliar diseases; drip or soaker delivery is favorable.
Fertility Management
Elderberries grow best at a soil pH of 5.5 to 6.5. A soil test should always be performed before any amendments are added. Soil fertility should be maintained to test at least 50 lbs./A phosphorous and 200-300 lbs./A potassium. An application of 10 lbs./A of nitrogen can be applied 4 to 8 weeks after planting. Mature (3 years old) elderberry plants will subsequently benefit from 60 to 80 lbs. of nitrogen per acre each year, applied in late March or early April.Pruning
Elderberries should be pruned annually starting in the winter after the second growing season, or once the plants have filled their space in the row. Pruning should be done in January or February, first removing all dead, damaged, and diseased wood. Then, prune out any branches that are older than 3 years old, as they will no longer be productive. Keep in mind that elderberry flowers and fruit develop on 1- and 2-year-old canes and branches, with the highest quality fruit and flowers found on second year wood. Some thinning of canes and branches will help to minimize humidity (and therefore disease pressure) and improve the likelihood of larger and higher quality fruit. Annual pruning is nearly complete when there remains a roughly equal number of 1-, 2-, and 3-year old canes, totaling approximately 6 to 10 canes per plant.Harvest
Elderberries will reach full production after 3 to 4 years, with potential yields reaching 2 to 4 tons/acre. Flowering will occur for most cultivars from mid-June to mid-July with the berries ripening in mid-August to mid-September. Flowers should be harvested when all flowers on a cyme are open.Berries are harvested by clipping off the cyme after all the berries are fully colored. The entire cyme must be clipped because it is difficult to remove berries from the cyme without tearing or causing loss of juice. However, whole cymes can be frozen and then berries can be removed from them without tearing the skin. Fruit is typically sold after being removed from the cluster. The berries are highly perishable, so they must be refrigerated within four hours of harvesting, and frozen or dried within five days of refrigeration to prevent degradation in quality. Flowers can be sold fresh, dried, or frozen.
Marketing
At present, promising marketing potential exists for elderberry, globally and locally. The multiple uses of both the fruit and flowers for wine, juice, jelly, jam, colorant, and dietary supplement products increase both the production and processing possibilities of elderberry across the market value chain. Growers may wish to make their own value-added products. But due to rapid perishability and potential toxicity, it is uncommon for growers to sell fresh elderberries directly to consumers. Some consumers, like chefs or bartenders, may prefer to receive fresh elderberries; others may be open to frozen or dried products, allowing growers to lengthen their sales window.
Pests and Diseases Associated with Elderberry Production
Overall, elderberry is a relatively pest and disease-resistant crop that can thrive in a variety of locations. However, as with all berry crops, it can be attacked or infested under conditions conducive to growth. Therefore, an integrated approach is critical to safeguard crop establishment while promoting beneficial insect populations and soil ecology. Obtaining disease-free plants and utilizing proper cultural practices greatly aids in chemical efficacy if warranted within an Integrated Pest Management (IPM) program. When designing an IPM approach, the first step is to determine what pests, diseases, and weeds are present, or likely to be present throughout the season, then seeking out specific management considerations per pest issue.
Starting with disease-free plants is the first step in a disease management program, followed by site selection, adequate plant nutrition, proper pruning techniques, water management, and removal of diseased materials once identified. Taken together, these promote plant vigor and resilient elderberry plants that are less susceptible to severe disease outbreaks. Pruning techniques that allow increased light penetration and airflow, which reduce humidity within the canopy, greatly reduce overall disease pressure. Once diseases have been identified, every effort should be made to prune out infected tissues during dry weather and destroy them away from the production area. Accurate identification of diseases that are present with the help of a diagnostic laboratory, and an understanding of the common diseases of elderberry, will greatly inform management approaches and material selections. If disease is a regular occurrence, preventative fungicide applications should be discussed with local Extension professionals who will consider production technique, pesticide application equipment, efficacy information, and contemporary regulations in this niche crop.
Pests
Spotted Wing Drosophila
[Order: Diptera]
The spotted wing drosophila (SWD) (Drosophila suzukii) fruit fly is a problem for small fruit producers throughout the United States. This fly can greatly reduce fruit yield or quality due to non-saleable fruit appearance and the presence of larvae in fruit. Eggs are oviposited into ripening and over-ripe fruit causing the fruit to become soft and drop prematurely. Ripe fruit should be harvested quickly, and over-ripe or damaged fruit should be removed from the production area. In cases where SWD is detected, monitoring SWD is critical to an IPM approach to combating this troublesome insect pest. Monitoring for adults should occur weekly near harvest via apple cider vinegar or yeast-sugar baited traps (see references). Monitoring for larvae in fruit relies on the larvae's sensitivity to salt, by placing fruit into a solution of 1 tablespoon salt to 1 cup warm water. If present, the small white conspicuous larvae will flee from the fruit into saltwater. Ripe fruit and dropped over-ripe fruit should be removed from the production and packaging areas quickly. Contact pesticide considerations: natural pyrethrins / synthetic pyrethroids [3A], and spinetoram or spinosad [IRAC-5]. Systemic pesticide considerations: cyantraniliprole [IRAC-28]. Applications target: during harvest and pre-harvest of fruit. Note, the use of broad-spectrum contact pesticides can have a negative impact on local beneficial insect populations and can cause a resurgence of other pests due to a reduction in natural predators.
Elder Borer Beetle
[Order: Coleoptera]
The elderberry or elder borer beetle (Desmocerus palliates) female adult lays eggs near the crown, and the larval stage (grubs) make their way into the crown and move towards the root system while feeding. As the grubs mature (a process that can take upwards of two years) and approach pupation, they move back up into the lower primary stem and pupate. Adults (beetles) feed on foliage and flowers prior to laying eggs and repeating the lifecycle. Removal of dead and infested canes from the site is critical to disrupt their lifecycle and reduce overall populations. Adult elder borer beetles emerge during bloom and should be a management target for petal fall through early summer. If the plant is heavily infested, insecticides may be warranted towards the end of the bloom period. However, the pollinator safety requirements must be followed as indicated by the label. Systemic pesticide considerations: imidacloprid [IRAC-4A] (only in agricultural settings in New Jersey), and chlorantraniliprole [IRAC-28]. Contact pesticide considerations: Synthetic pyrethroids [3A]. Note, the use of broad-spectrum contact pesticides can have a negative impact on local beneficial insect populations and can cause a resurgence of other pests due to a reduction in natural predators.
Elder Shoot Borer Moth
[Order: Lepidoptera]
Achatodes zeae, commonly known as the elderberry cane or shoot borer, elder shoot borer moth, or spindle worm, causes the damage while in its caterpillar (larval) growth stage. Eggs hatch during the spring months (April-May) and larvae begin feeding on developing leaves but quickly move into lateral shoots then feed within elderberry vasculature, making their way towards the lower primary stem. This causes a restriction of new growth and ultimately impacts fruit production. In early summer, as the caterpillar is approaching pupation, they move towards fully dead canes, emerging in July or August as adult moths, and begin laying eggs on 1+-year-old canes that will hatch the following spring. Removal of dead and infested canes from the site is critical to disrupt their lifecycle and reduce overall populations. Some commercial recommendations note the use of systemic diamide insecticides [IRAC-28] during the summer months. However, it should be noted that the insect is protected within the stem, therefore contact insecticides are mostly ineffective.
Caterpillars and Sawflies
[Order: Lepidoptera]
The Cecropia Silk Moth (Hyalophora Cecropia) caterpillar and Eastern Tent Caterpillar (Malacosoma americanum) as well as [Order: Hymenoptera] sawfly larvae are some of the more common caterpillar and caterpillar-like pests known to damage elderberry foliage. However, each pest presents a slightly different situation. Cecropia moth caterpillars grow into very large specimens yet are typically only nuisance pests that do not require management. They feed throughout the summer months, spin a cocoon as cooler fall days approach, and emerge as very large moths in late spring. Conversely, Eastern Tent Caterpillars are capable of severe defoliation and generally decreasing the tidiness of the production area because of their silk 'tents.' Management relies on early detection, as once the tents are large, it is very difficult to control via chemical means. Direct removal and destruction of these structures is a best management practice versus pesticides targeting Lepidoptera. Although they look like caterpillars, sawflies are the larval stage of a wasp-like Hymenoptera that are present and cause most of the damage during the pre-bloom stage of elderberry production. Systemic pesticide considerations: acetamiprid [IRAC-4A] (only in agricultural settings in New Jersey). Contact pesticide considerations: spinetoram or spinosad [IRAC-5], azadirachtin [IRAC-UN] and carbaryl [IRAC-1A]. Note, the use of broad-spectrum contact pesticides can have a negative impact on local beneficial insect populations and can cause a resurgence of other pests due to a reduction in natural predators.
Japanese Beetles
[Order: Coleoptera]
Japanese beetles (Popillia japonica) can cause severe damage and skeletonization to elderberry foliage as adults, and minor damage to elderberry roots during their larval (grub) stage. Grubs overwinter below the frost line and begin feeding on roots (typically grasses) as the season begins to warm. During late spring-early summer the grubs pupate and emerge as adults (beetles) about 1 month later. Adult beetles can fly considerable distances and are active for about 30-45 days post emergence. Towards the end of the adult activity window new eggs are laid, hatch, and again begin feeding on organic matter / roots until the soil begins to cool in the fall, and the grubs move back below the frost line. Systemic pesticide considerations: acetamiprid [IRAC-4A] (only in agricultural settings in New Jersey). Contact pesticide considerations: azadirachtin [IRAC-UN], zeta-cypermethrin (synthetic pyrethroid) and natural pyrethrins [IRAC-3A], and carbaryl [IRAC-1A]. Note, the use of broad-spectrum contact pesticides can have a negative impact on local beneficial insect populations and can cause a resurgence of other pests due to a reduction in natural predators.
Scale Insects, Mealybugs, and Aphids
[Order: Hemiptera]
Piercing sucking insect refers to the mode in which these insects feed, they pierce with their beak / proboscis and siphon plant fluids whether that be from local cells, phloem, or xylem. Many of these piercing sucking pests produce a sugary excrement known as honeydew which is then colonized by sooty mold fungi leading to unsightly black to dark green covering of foliage, stems, and fruit. In heavily infested plants, sooty mold can lead to a reduction in photosynthesis but is more importantly a sign that the plants are being chronically stressed by these sap feeders and increased management efforts are warranted. In these cases, growers may also notice a higher abundance of ants, which are protecting these pests in exchange for their nutritious honeydew excretions. This group of insects can represent both nuisance pests, as is the case with most aphid infestations (see virus section), as well as serious pests. Two major scale insect pests of elderberry include European Fruit Lecanium scale (soft scale) (Parthenolecanium corni) and the San Jose scale (armored scale) (Quadraspidiotus perniciosus). In both cases, the adult scale insect is sessile and extremely difficult to control. However, the juvenile aka crawler stage, that has not yet excreted a waxy or armored protective layer, is much easier to manage.
Pesticide options should be discussed with local Extension personnel. However, there are two main chemical-based control tactics: suffocation of adults and crawlers or targeting scale crawler emergence. Generally, 'dormant oil' (2–4% dilution rate) applications are made before bud break when temperatures are consistently above freezing to suffocate overwintering insects and mites. Mealybugs, specifically Grape mealybug (Pseudococcus maritimus) in elderberry, are very similar to scale insects in that they secrete protective coatings to avoid predation, yet they are mobile throughout their lives and therefor sensitive to management throughout the growing season. These pests represent a key food source for native beneficial predator insects, therefor sub-economic thresholds of these pests can allow for homeostasis with limited pesticide usage, especially if the pesticide program centers around Insect Growth Regulators (IGRs) that are less damaging to predator populations. Note, the use of broad-spectrum contact pesticides can have a negative impact on local beneficial insect populations and can cause a resurgence of other pests due to a reduction in natural predators.
Jessie's Bug
[Order: Hemiptera]
Jessie's bug (Neurocolpus jessiae), a true plant 'bug,' is a piercing sucking insect that targets developing leaf buds leading to subsequent necrotic foliage, leaflet margin necrosis, and failure to produce cymes and fruit. This pest is best managed early in the production season during the pre-bloom stage of growth. However, pollinator safety must always be accounted for, and all pesticide labeled stipulations surrounding pollinators must be strictly adhered to. Systemic pesticide considerations: thiamethoxam or acetamiprid [IRAC-4A] (only in agricultural settings in New Jersey). Contact pesticide considerations: bifenthrin or zeta-cypermethrin (synthetic pyrethroids) and natural pyrethrins [IRAC-3A], azadirachtin [IRAC-UN], and carbaryl [IRAC-1A]. Note, the use of broad-spectrum pesticides can have a negative impact on local beneficial insect populations and can cause a resurgence of other pests due to a reduction in natural predators.
Thrips
[Order: Thysanoptera]
Commonly, Eastern flower thrips (Frankliniella tritici) are implicated in elderberry production. These pests favor flowers, can transmit viruses, and under ideal conditions, can occur in extremely dense populations. This pest is best managed pre-bloom to post petal-fall stages of elderberry production. However, pollinator safety must always be accounted for, and all pesticide labeled stipulations surrounding pollinators must be strictly adhered to. Systemic pesticide considerations: imidacloprid or acetamiprid [IRAC-4A] (only in agricultural settings in New Jersey). Contact pesticide considerations: azadirachtin [IRAC-UN], spinetoram or spinosad [IRAC-5], insecticidal soaps, and natural pyrethrins [IRAC-3A]. Note, the use of broad-spectrum pesticides can have a negative impact on local beneficial insect populations and can cause a resurgence of other pests due to a reduction in natural predators. Note, thrips can develop resistance to pesticides quickly, therefore pesticide rotation by mode of action is critically important for pesticide stewardship.
Eriophyid and Spider Mites
[Class: Arachnida]
Eriophyid mites [Family: Eriophyidae] and spider mites [Family: Tetranychidae] represent a mostly nuisance group of elderberry pests. Eriophyid mites overwinter in dormant buds and cause damage to developing tissues, with symptoms ranging from cupped, folded, or otherwise distorted new growth prior to the pre-bloom stage of production. Spider mite stippled-foliage damage is typically associated with warm dry summers, as these mites are regulated naturally by entomopathogenic fungi in warm humid conditions. Generally, these pests do not warrant pesticide applications as native predatory mites keep pest mite populations in check. Contact pesticide considerations, if warranted: horticultural oil (1-1.5% dilution), insecticidal soaps (1-2% dilution), natural pyrethrins [IRAC-3A], neem oil and its derivatives [IRAC-UN]. Note, the use of broad-spectrum pesticides can cause a severe resurgence of spider mite populations due to a reduction in natural predatory mite populations.
Common Vertebrate Pests
Humans are not the only vertebrates that enjoy elderberries. Deer, squirrels, chipmunks, rabbits, raccoons, opossums, and woodchucks have all been observed feeding on elderberry stems, leaves, and fruits. In some cases, feeding damage can be severe, warranting the use of canopy netting, electric or double fences, trapping, scare devices, and feeding-deterrent material sprays. Many mammals, particularly voles, woodchucks, and rabbits, can cause severe girdling issues in woody plants if they are allowed to feed or chew on the basal bark or near-surface roots, which can be common in years with heavy persistent snowfall. Trapping or other means of varmint removal may be warranted if damages are severe. Birds represent both friend and foe in the production of elderberries, as some feed on would-be detrimental invertebrate pests while others present as a crop nuisance and food-safety concern by defecating on the berry crop. Netting and scare devices (faux bird of prey, reflective-, light-, laser-based deterrents, scarecrows, etc.) may be practical for some operations as bird removal, lethal or otherwise, is not allowed in most cases due to regulations.
Diseases
Alternaria and Colletotrichum Foliage and Fruit Diseases
Alternaria and Colletotrichum are fungal diseases (C. acutatum, C. kahawae, C. salicis) that cause minor leaf spots, foliar necrosis, and fruit rots on elderberry. These diseases generally infect elderberry foliage and developing ovaries / immature fruit when the following criteria are met; at or near the bloom period or fruit maturation, prolonged periods of leaf wetness, and temperatures at or above 77ºF for sustained periods. Pesticide-based management can begin pre-bloom and extend until harvest in areas where disease pressure is high, or prior issues have been noted. Fungicide considerations: Polyoxin D [FRAC-19], azoxystrobin or pyraclostrobin [FRAC-11], pyraclostrobin + boscalid [FRAC-11+7], azoxystrobin + difenoconazole or + propioconazole [FRAC-11+3], propioconazole [FRAC-3], fluopyram + pyrimethanil [FRAC-7+9], cyprodinil + fludioxonil [FRAC-9+12], iprodione [FRAC-2], and Reynoutria sachalinensis extract [FRAC-P05]. Note, rotation by mode of action is critical in safeguarding against pesticide resistance. Pre-harvest intervals (PHI) must be strictly followed. If the crop is destined for export, pesticide residue limits per compound must be considered.
Powdery Mildew
A common group of foliar pathogens that are visible to the naked eye as white or gray dust-like (i.e. powdery) fungal structures. Powdery mildew readily colonizes most aerial plant parts but often attacks and stunts developing shoots and buds. Flowers and fruit can also be damaged, leading to immediately evident yield losses. Overhead irrigation should be avoided as moisture can be trapped within the dense canopy of elderberries, resulting in more abundant and more frequent disease. To combat this, the canopy should be regularly thinned to increase airflow and foster faster foliage drying times. Sanitation or removal or infested leaf litter, dead canes, or otherwise diseased crop debris is the most critical practice in avoiding powdery mildew.
Major Viral Diseases
Two important viruses have been associated with Elderberry: Tobacco Mosaic Virus (ToMV) and Tomato Ringspot Virus (ToRSV). These viruses can be transmitted from Solanaceous crops (petunia, tobacco, tomato, or potato) and nightshade weeds (Solanum spp.) to elderberry via sap-sucking insects, principally aphids.Elderberries are known to be a reservoir for many viral diseases and often remain asymptomatic for long periods of time. Preventing viruses from entering a new planting revolves around acquiring certified disease-free plants (aka 'clean plants'), from well-established nurseries, and management of insect vectors. As a best management practice all tools, from hand pruners to equipment, should be regularly cleaned and sanitized to disrupt the spread of viruses via mechanical means.
Rust Fungi
Although not particularly destructive, Puccinia bolleyana causes galls and abnormal growths that should be removed and destroyed. This pathogen alternates infection between elderberry and its secondary hosts (sedges), therefore identification and removal of sedge weeds in the surrounding area may help control this pathogen. This pathogen is active and should be managed prior to blooming during the green-tip phase of elderberry growth. Fungicide considerations: azoxystrobin or pyraclostrobin [FRAC-11], propioconazole [FRAC-3], pyraclostrobin + boscalid [FRAC-11+7], Polyoxin D [FRAC-19], azoxystrobin + difenoconazole or + propioconazole [FRAC-11+3], and Reynoutria sachalinensis extract [FRAC-P05]. Note, rotation by mode of action is critical in safeguarding against pesticide resistance.
Bacterial Spot
Other pathogens may cause foliar issues through the production cycle, including a bacterial spot disease caused by Pseudomonas viridiflava, which has caused economic damages in some parts of the United States, however very little is known about management.
Verticillium Wilt
This soilborne, fungal disease is caused by Verticillium dahlia and is one of the most common vascular diseases of elderberry. The fungus initially attacks roots and crowns, then moves into the vascular system leading to rapid wilting of whole stems or plants. This pathogen attacks a large host range of plants including many crops and weeds within Solanaceae and Amaranthaceae. Ideally, avoid areas where these plants have been grown as Verticillium propagules can remain dormant for many years. If this pathogen is detected, the effected plants should be removed and the soil in that area either replaced, solarized, or fumigated as this pathogen is extremely difficult to control with chemicals. Maintaining plant vigor through appropriate fertilization and not overwatering are also critical when managing Verticillium.
Fungal Canker Diseases
Cankers are characterized by sunken and necrotic regions of stems that can weaken large portions of the plant and are typically associated with fungal species of Botryosphaeria, Diaporthe, or Nectria in elderberry production. They often sporulate during wet/humid springs, so protective fungicide applications are warranted if this disease type is present. Additionally, remove infected areas by pruning at least 6 to 12 inches back from infection site and destroy the residues away from the production area. Avoid pruning during wet weather as this may exacerbate the spread. This pathogen is extremely difficult to control with chemicals.
Root and Heartwood Diseases
Crown / Root rotting Helicobasidium, Phymatotrichum, and Xylaria species fungi can cause similar wilt and branch death conditions. Heartwood fungal pathogens Fomes, Hymenochaete, and Polyporus species are typically characterized by the presence of large fungal fruiting bodies such as shelves, or fungal growths protruding from the crown or root zone area. These pathogens are most often problematic when plants are overly stressed, over-watered, over-fertilized, or regularly wounded by machinery or pests. Avoiding these practices and managing plant stressors can prevent the use of fungicides for these root, crown, and heartwood issues. Phytophthora root rot diseases are common throughout economically important crops with management centered around adequate nutrition, well-draining soils, and sanitation of tools and equipment. Phosphonate fungicides [FRAC-P07] activate plant defenses while providing some level of protection against many root diseases.
References and Resources
Resources with Video
June 2025
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