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Southern blight is a fungal disease caused by Sclerotium rolfsii. It is also known as southern stem rot. The disease is a problem primarily in the Piedmont apple growing region in the southeastern United States. S. rolfsii is a widespread pathogen that affects several hundred plant species and the list of host plants includes azalea, black walnut, crabapple/apple, forsythia, hosta, hydrangea, rose, viburnum. The fungus affects the lower stems and roots of apple trees, killing the bark and girdling the trees. Common symptoms are yellowing leaves, sudden wilting, stems turning brown and dying near the soil line, and plant death (Figure 1). White mycelium may appear on the soil surface, on the lower stem/trunk, including just underground and on plant debris. Clusters of spherical structures called sclerotia may also appear on the host plant and plant debris close to the soil line (Figure 2). Infected trees can usually survive for a month, but plant death often occurs more rapidly shortly after symptoms are noticed. Most herbaceous plants wilt and die in a few days or less. Tree death usually occurs rapidly. Sclerotium rolfsii overwinters in the soil and in plant debris as sclerotia. The light brown or pink sclerotia serve to spread the fungus. This fungus can be spread in runoff water, eroding soil particles and on items such as tools, shoes and plant containers. Generally, the fungus doesn't survive at depths greater than 2 to 3 inches; however, it can survive for years in the soil. It prefers a wet environment and acidic soil conditions. 


Figure 1. Yellowing leaves, sudden wilting, stems turning brown on infected apple tree. Image: Dr. Elina Coneva

Figure 2. Clusters of sclerotia appear on the infected apple tree. Image: Dr. Elina Coneva

The disease is most severe on 1- to 3-year-old trees. Root, crown, and collar tissues become resistant to infection as the bark thickens with age.

Typically this disease appears during the hot months of June, July and August. A grower should look for scattered dead plants in the orchard. To manage the disease, avoid planting apple trees on sites where the disease has been severe on previous crops such as peanuts, clover, tomatoes, and soybeans. Remove infected plants and soil surrounding the plant. Keep the soil around the bases of trees free of dead organic matter that serves as a food base for S. rolfsii. Some differences exist in rootstock susceptibility. The most resistant rootstock currently used is M.9. There are no chemicals registered for control of southern blight on apple trees.


Elina Coneva

Extension Specialist, ACES





The Alabama Cooperative Extension System and Alabama Beginning Farmer Program have released the "Farming Basics" online curriculum that is a great place for self-paced learning for all producers. A full news release from Alabama Extension can be found here. At present, the curriculum is divided into multiple chapters with several sections or learning modules under each topic. Major topic areas or chapters include Marketing & Farm Management, Pesticide Safety, Food Safety, Basic Crop Production, and Pest Management. Many more topics areas for expansion of the online curriculum is in the future. Subject matter experts from several extension teams and nonprofit collaborators provided the useful content that is available free of cost to anyone interested. To enroll directly in the "Farming Basics" course, visit https://aces.catalog.auburn.edu/courses/acesfarmingbasics01 and then watch the introductory video to learn about course navigation. This ADA Compliant course includes notes, videos, and quizzes to make the learning process interactive; the course automatically generates a completion certificate for participants based on your registration information. The course must be completed within 60 days of initiation and it saves progress made by participants for the duration.  Growers are encouraged to check out www.alabamabeginningfarmer.com for a complete list of on-farm support services and educational resources available in print and alternative formats.

To provide us a detailed review about the online course, please take this feedback survey after completion or take the survey on your phone using the QR code (on iPhone, start camera and scan the code only to access the survey on the default browser; a QR code reader may be needed on Android phones). Thank you so much. 

QR Code - Farming Basics Online Course Survey 2018.png



Ayanava Majumdar

Extension Entomologist & Beginning Farmer Program Coordinator



Dr. Juan Silva and Dr. Elizabeth Canales at Mississippi State University invite you to participate in a survey to examine farmers' adoption of food safety practices and third-party food safety audits. The objective is to identify the barriers to food safety adoption and the challenges faced by fruit, nuts, and vegetable growers of various operating sizes. Outputs from this research will help inform extension and other outreach educational efforts.

Participation in this survey is voluntary and there are no risks involved with this survey. You may discontinue and exit the survey at any time. Any information you provide in this study is strictly confidential, and no identifying information will be collected. Only aggregated summaries from this study will be published. If you have any questions about this research, please feel free to contact Dr. Canales by calling (662) 325-2516, or via email at dec249@msstate.edu.

The survey takes approximately 15 minutes. At the end survey, you will have the option to enter a drawing for the opportunity to win one of several $100 gift cards. If you agree to participate in this survey, please click the following link to access the survey:

https://msudafvm.co1.qualtrics.com/jfe/form/SV_3pWpHmt0nox8wM5

 

 


Chili thrips have become a significant pest in South Alabama and rival red headed flea beetle for the number one pest in Alabama container nurseries. Heading the pleads of growers, Auburn University researchers Dr. David Held and Dr. Jeremy Pickens put into action a plan to improve upon the current Chili thrips management strategies. In 2017, they were awarded a $25,000 Specialty Crop Block Grant to fund the development of these strategies. One of the issues they plan to tackle is making applications of insecticides more effective through easier monitoring techniques and understanding how to get the most out of a spray application. University of Florida researchers have shown that Chili thrips in ornamental nurseries were more active in flight between 10 A.M. and 4 P.M. Dr. Held thought this may indicate that the effectiveness of an insecticide applications for Chili thrips could be influenced by the time of day. A trial was conducted at a collaborating nursery that included 4 treatments spread out over 1,500 plants. To determine an optimum time range to spray, treatments included: a non-treated control, a morning (before 10 A.M.), midday, and evening (at 4 P.M.) spray. The insecticide used in the trial was spinosad (Entrust® SC, DOW AgroScience). In order to test the efficacy of these treatments, cuttings were taken off individual plants and submerged in alcohol to collect thrips both before and after treatment.

As expected, timing did play an important role in efficacy. The majority of thrips collected were immature (89-90%). That makes sense as many of the adults fly off during collection. Morning treatment reduced total thrips population from pretreatment counts by 83% compared to the water treated control with 50% reduction. No differences were observed between midday (47% reduction) and evening (60% reduction) applications. Applying pesticides at midday had a lower reduction in thrips than the non-treated control. Only one insecticide was tested, but these results suggest that spraying in the morning whenever possible can provide more effective control than sprays later in the day. Morning sprays are not the most convenient in working around REI's but the improvement in efficacy would likely make up for any added hassle. 

Find this information useful?  Please take this 4 question survey.  These surveys are easy to do on your phone.  It is quick and easy. Thank you for your feedback.


Figure 1.  Overview of the trial.                    Figure 2.  A sample of how Chili thrips were counted under the microscope.


Jeremy Pickens, Extension Horticullturist, Department of Horticullture, Auburn University

David Held, Department of Horticulture, Auburn University


Downy mildew was observed on pumpkins in a commercial field in Shelby County and in research plots at Brewton and Tallassee this week.  The moisture we have seen in some parts of the state has favored the development of the disease.  We did see downy mildew on cucumber in our downy mildew monitoring plots in late June and early July, so disease inoculum was already present in the state.  Please refer to this publication in regards to fungicide recommendations and cultural practices to follow to try to manage this disease.  The publication was developed by Dr. Tony Keinath, Extension Plant Pathologist. at Clemson University.



Zonate leaf spot on tomato is a disease not commonly seen.  Zonate leaf spot is caused by the fungus Hinomyces moricola, primarily a disease of tomato foliage.  Its  occurs sporadically in the field, though there have been reports of severe defoliation and yield loss in other states.  The disease has not been seen on tomatoes in Alabama.  However, it is often confused with symptoms of late blight.  The Auburn diagnostic lab has seen this disease on pecan occasionally, as it has been reported on 73 different plant species, including woody perennials and annual succulents.  The disease gets its name from the development of large, circular leaf lesions with distinct concentric rings.  Information is lacking on effective fungicides for management of zonate leaf spot.   



 

Ed Sikora and Kassie Conner

Extension Plant Pathologists, ACES

 


Grape root borer is found throughout the eastern United States from Pennsylvania and Ohio south but is much more prevalent in southern states. It is a serious threat to grapes in Alabama vineyards. Adults are brown moths with thin yellow bands on the abdomen and resemble some paper wasps. The front wings are brown while hind wings are transparent. Many "look-a-like" moths resemble grape root borers (Vitacea polistiformis), making this a difficult pest to monitor. Male grape root borers are characterized by the unique presence of four pencil-like tufts on the tip of the abdomen.


Grape root borer adult (A) and larvae (B). Photo (A) by Buckeye Apellation, OSU, and photo (B) by James Solomon, USDA Forest Service, Bugwood.org. 

Symptoms:

The damaging stage of grape root borer is the larva. The eggs hatch on the soil surface and the larvae tunnels into the root system. Infested roots contain tunnels filled with reddish, sawdust-like frass (excrement), and trunks may be girdled. As with many woodboring pests, damage may not be evident for several years and, once detected, it is often too late to control this pest. Symptoms include yellowing of leaves, smaller leaves and berries, reduced shoot growth, vine dieback, and reduced yield. Damage ranges from just a few feeding sites to complete root destruction. Diagnosing grape root borer is difficult because these symptoms can also be related to pathogens and environmental conditions. Complete diagnosis includes digging up symptomatic vines and inspecting the roots and/or monitoring for the presence of pupal skins around the base of the vine.

Management:

Cultural methods for control of grape root borer include mounding soil under vines just after pupation in order to reduce adult emergence. If you find any pupal skins on the soil around the base of the vines, cover the pupae with 6 inches of soil, which effectively aborts emergence.

Two species of Heterorhabditis nematodes have shown promise as biological control agents against grape root borer larvae. Pheromone-baited traps are recommended for monitoring adult moths. These traps should be placed about 100 m apart inside the vineyard and along adjacent woodland boundaries. Monitoring information may be useful for proper timing of insecticide applications. It is critical to have insecticides applied on the soil surface at the time of egg hatch. Once larvae reach the root system insecticides are ineffective.

Recommended sources:

Grape Root Borer Pest Management in Florida VineyardsUniversity of Florida

The Grape Root Borer in TennesseeUniversity of Tennessee

http://articles.extension.org/pages/54593/grape-root-borer


Elina Coneva

Extension Fruit Crops Specialist



Fleas are some of the most annoying biting pests known to man and pets.

In Alabama, there are two common flea specie, the dog flea and cat flea. Of the two flea species, the cat flea is the most abundant species with the ability to survive longer and reproduce better on human blood than dog flea. Both flea species make their way into the homes of unaware pet owners. Life becomes miserable as they make their presence known through irritating bites and sometimes more disturbing symptoms such a tapeworms.

Fleas occurs all year round, but may go dormant during extreme hot summer or cold winter. Fall is the worst season for fleas. This is because fleas thrive with an increase in precipitation, the temperature staying around 70 degree, and the leaf piles that are humid and dark.

Outdoors, fleas typically take up residence in shaded, humid areas away from bright sunlight, where your pets are more likely to play and rest. It just takes is a few fleas to get established in your yard before you have a full blown flea infestation on your hands.

Fleas get into homes mostly by hitching a ride on pet, and are also able to attach themselves onto humans. Inside, fleas can live quite comfortably where pets play/feed and sleep. Common sites include pet sleeping mats, carpet and rug, upholstered furniture, floor cracks and tile joints.

Fleas reproduce very efficiently. Adult flea blood-feed within minutes of jumping on animal. Mating and subsequent egg laying occurs within 24 hours. A female flea lay 25-50 eggs per day, and can produce up to 5,000 eggs during lite time. The eggs are laid in pet fur, but soon fall off into carpeting, beneath the cushions of furniture, and wherever else the pet rests, sleeps, or spends time.

Flea control includes treating the environment (indoor and outdoor) as well as the pet. It is desirable to treat the premises along with the pet.

If flea infestation is confirmed, pet owners should first consider cleaning the pets and the infested areas where pets spend most of their time and remove pet from infested areas.

Treatment of pets: Adult fleas spend most of their time on animal, not in the carpet. This is why treatment of the pet is an essential step in ridding a home of fleas. Pets can be treated either by a veterinarian or the pet owner. Products for treating pest are available in the forms of oral medications and topical "spot-on" solutions, as well as sprays, collars and shampoos. Topical solutions (spot-ons) involves applying a few drops of pesticide along the pet's back or between the shoulder blades. Oral/chewable tablets work systemically within hours of ingestion. ) Be sure to read the product label to ensure you are purchasing the correct formulation and dosage for your pet. It is usually prudent to consult a veterinarian for the most appropriate treatment for your pet.

Rid your home of fleas: The first step should be removal of pet bed, toys, and other items from floors and under beds so that all areas will be accessible for treatment. The pet bedding should be washed or dry-cleaned and all carpet, upholstery, rugs and mats should be vacuumed daily. Many different products are available for home flea treatment. These products are in the formulations of powder, liquid or aerosols. The most effective formulations contain both an adulticide (e.g., permethrin) effective against the biting adult stage, and an IGR (methoprene or pyriproxyfen), necessary to provide long-term suppression of the eggs, larvae and pupae .IGR products are the most used for indoor treatment because of their safety and high efficacy. IGR stands for Insect Growth Regulator, works specifically on insects and stop the development of flea egg and larvae. Application should be thorough and re-treatment is often necessary.

Treatment of yard: Rake up fallen leaves regularly and immediately bag and dispose of them in a secure trash receptacle. Regularly clean out pet playing/resting/sleeping areas, and, when necessary, treat these sites with pesticides. Similar to indoor treatments, outdoor treatments should focus on areas where pets rest, sleep, and run, e.g., doghouse and kennel areas, along fences, under decks, and next to the foundation, rather than treat the entire yard or areas esposed to full sun. Insecticide formulations containing an IGR such as pyriproxyfen (Archer® Insect Growth Regulator, NyGuard® IGR Concentrate) prevent hatching/development of flea eggs and larvae for several months.

Fleas can be successfully controlled by diligently following the steps outlined above. Homeowners who lack the time to control fleas themselves or who are uncomfortable applying pesticides may wish to enlist the services of a professional pest control firm.


Xing Ping Hu and Arthur Appel

Department of Entomology and Plant Pathology



The spotted wing drosophila (SWD) is an invasive insect first reported in California in 2008.  It has since spread throughout the US including in the southeast.  In Alabama, SWD was first observed on yellow sticky traps in 2011 in Coosa and Chilton counties and was later found in Elmore County.  Spotted wing drosophila will infest a broad range of edible crops such as tree fruit, berry, nut, and vegetable crops.  Raspberry, blackberry and blueberry crops are highly susceptible to SWD infestation.  For more information on SWD, please go to www.aces.edu/timelyinfo/Horticulture/2011/July/july2011.pdf.

The African fig fly, Zaprionus indianus Gupta (Diptera: Drosophilidae), is another invasive fruit pest that has spread rapidly through much of the eastern United States.  The Zaprionus genus contains 59 species. The genus is closely related to Drosophila.  The African Fig Fly (AFF) was first found in the U.S. in Florida in 2005. The insect spread rapidly and now can be found throughout much of the North American continent.  Though AFF can be found in ripe fruit on trees, researchers question whether they can infest intact, tree-ripening fruit as they are mainly found in rotten fruit on the ground.  Conversely, in certain types of figs, the AFF will lay eggs in the ostiole (Figure 1)  which is a small orifice at the distal end of the fruit (not all fig varieties have an ostiole) giving developing larvae access to the interior of the fruit.


The AFF infests a broad range of edible crops, as is the case with its close relative SWD.  The SWD female can lay eggs in developing fruit mainly because of the serrated ovipositor, which gives her the ability to penetrate intact fruit.  The AFF on the other hand lacks a serrated ovipositor, which purportedly limits laying of eggs to decaying or damaged fruit or in fig varieties that have an ostiole.  The eggs of the AFF are creamy white and develop into larvae that are white to light yellow and less than 1 mm in length.  A single AFF female can produce 58 offspring. 

At 3.5 mm in length the adult AFF is considerably larger than the SWD.  It is also distinguishable from the SWD because s a prominent pair of white stripes that run the length of the body from the antennae to the tip of the thorax.

Monitoring

Management of fruit flies should not begin until they have been caught in monitoring traps.  Monitoring traps can be containers that are partially filled with bait or specialized, yellow sticky cards.  Container traps are often the preferred method for monitoring and can either be ordered online (Marginaldesign.com) or constructed from household materials.  For more information on construction, please go to www.aces.edu/timelyinfo/Horticulture/2011/July/july2011.pdf).  If you suspect SWD or AFF infestation, please contact your Regional Extension Agent for identification confirmation. 

Control

Once SWD or AFF has been properly identified, a spray program can begin.  Insecticidal sprays used to control SWD also work in the control of AFF.  As always, consult with your Regional Extension Agent and refer to the product label for proper application.  Additional control can be achieved through proper sanitation, which involves removal of fruit from the ground and overripe or decaying fruit from the plant.  In the case of small or home orchards, specially designed bags used to cover individual fruit can serve as a barrier to these pests.  Application of these bags will be time consuming and impractical for most commercial operations.  Frequent harvests will also reduce the potential for infestation of ripening fruit.

Monitoring traps were deployed at a local tree and fruit crop nursery in Chilton County.  The first captures were recorded on May 31.  The first six weeks of monitoring are presented below (Figure 2).  Currently, the number of captures have increased compared to the first four weeks but increasing.  Number of male SWD (blue bars) are low and have not increased during the four-week period.  The number of AFF were highest during the first three weeks but were substantially lower than the number of female SWD by week 4.  However, the population may increase. Last season, the number of AFF increased later than SWD but vastly outnumbered SWD throughout most of the season.  Additionally, as the number of AFF increased the number of SWD decreased.

Spotted wing drosophila continues to be an important pest in fruit operations in the Southeast and across the nation.  Research investigating the most effective monitoring and pest management strategies are currently underway at various institutions.  Less is known about AFF.  Since the female does not have a serrated ovipositor, infestation of healthy developing fruit seems unlikely.  However, for fig, particularly those types that have an ostiole, AFF is a greater concern.  Last season, a farmer in Alabama reported that an entire fig crop was affected by AFF.  Calls reporting damage due to AFF in figs are increasing. 

Researchers are concerned about the increased population of AFF.  Rarely would an AFF be observed in monitoring traps in 2016.  This status was elevated from a rare observation to an almost exclusive observation in 2017.  Monitoring of AFF as well as SWD will continue.  More information will be presented as it made available.

Edgar Vinson, Extension Specialist

Charles Ray, Entomology and Plant Pathology


 


slug pic1 - ayanava majumdar.JPGFrequent rainfall and excessive soil moisture in the fall and early spring can bring some unusual problems for vegetable gardeners and farmers – slugs are one of them (pictures show slugs infesting cabbages in Central Alabama). Slug build-up is also favored by the presence of high organic matter in heavy (clayey) soil; organic matter not serves as a food source but also provides shelter from the environment and natural predators.

While slugs are invertebrate animals with soft bodies, snails have a hard shell that covers most of the body. Attack from slugs seem to occur at various stages of vegetable crops with high intensity in the late stages of crops that can lead to direct feeding damage and crop contamination. Slugs are very common on brassica crops grown during cooler weather in Alabama and several slugs may hide inside the maturing crop. Many crops have zero tolerance for slug contamination which may lead to crop disaster. In recent years, we have experienced slug activity in cabbage fields along with the yellowmargined leaf beetles resulting in complex pest outbreaks. Literature suggests that female slugs lay eggs in soil in small batches in damp areas; immature stages seem to have a limited foraging distance with repeated feeding in certain areas over several days.

Slug monitoring:  Some publications suggest using upturned plastic pots baited with chicken feed or other cereal based food (including malted beverages) as a way of attracting slugs early in the season for general population assessment. Unfortunately, using a number of slug traps with baits is often a cumbersome process and producers often get surprised when slugs appear on the crop. BioCare Slug Trap is a commercial vegetable-extract based slug trap that may be sufficient to monitor or trap out slugs in small areas.

Cultural tactics:  Manage surface residues and till the soil when necessary to prevent slug buildup. Drain waterlogged areas in and around crop fields when possible, or use abrasive materials such as sand in wet areas not under crop production. Limit irrigation or overhead watering during weather with frequent rainfall – use a soil moisture meter or other devices to accurately determine crop irrigation needs. Since slugs seem to like certain crops (e.g., soft-leaf brassicas), crop rotation, early planting, and timely harvest may help reduce the overall population levels.

Natural enemies:  Ground-dwelling carabid beetles are aggressive predators of slugs, but not sufficient to provide control in the environmental conditions that favor slugs in the first place. Nemaslug, sold commercially by BASF in the Eurpoean market, is an organic control option that uses endoparasitic nematodes to destroy slugs.  

Molluscicides: Slugs are not insects; so many insecticides do not provide control. Commercial snail and slug-control materials typically contain:

  • Iron phosphate (e.g., Sluggo by Montery, OMRI-certified; Bonide Slug Magic for Gardens),
  • Volatile oil blend (Monterey All Natural Snail & Slug Spray),
  • Diatomaceous earth with amorphous silica (Perma-Guard Crawling Insect Control)
  • Bait premix of iron phosphate and spinosad (Bug-N-Sluggo by Certis, Monterey Sluggo Plus)
  • Sulfur (Bug-Geta by Ortho)
  • Metaldehyde (Southern Ag Snail & Slug Bait, Deadline Mini-Pellets)

    slugs on cabbage - ayanava majumdar.JPG 

The drawbacks for some of the listed formulations is the high cost, low availability, and restricted crop uses. Multiple applications of products may also be needed for sustained effect. Always read the product label and/or consult the manufacturer before using molluscicides on high-value crops, since field research-data is very limited for many products. Check the OMRI symbol for organic farming use. Contact Alabama Extension Regional Extension Agent for correct pest identification and development of IPM plan.  

References:

Ayanava Majumdar,

Extension Entomologist & State SARE Program Coordinator


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