eGRO Alerts
This page lists alerts from the current season (vol.13), vol.12 from 2023 vol.11 from 2022 and vol.10 from 2021.
For earlier seasons please click here for the archives dating back to 2012.
13.21 - Hydrangea Leaf Distortion: 2024 Sponsors Hydrangea Ringspot Virus confirmed
A recent eGRO alert on “How to Deal with Diagnosis” (https://www.e-gro.org/pdf/2024-13-18.pdf), stressed the importance of looking for symptom patterns and getting an accurate diagnosis for a plant problem.
13.20 - PGRs: Where to Start
Many greenhouse growers regularly use plant growth regulators or retardants (PGRs) to elicit desirable crop responses. Those new to using PGRs should consider their goals and several factors prior to making applications.
13.19 - Biostimulants for Greenhouse Ornamental Crop Production
This article provides an overview of what biostimulants are, how they can improve the quality of greenhouse ornamental crops, and key considerations for choosing and using biostimulant products effectively.
13.18 - How to Deal with Diagnosis
Correctly identifying the cause of a problem is the first step in effective and economic management practices. Learn some tips about how to diagnose the cause of plant problems.
13.17 - Much Ado About (a) Thrips
Managing this new pest partly depends on recognizing it and choosing effective controls, informed by data from recent research specifically targeting this insect
13.16 - Daminozide Dilemmas: Avoiding Flower Bleaching in Spring Bedding Plants
Daminozide is a widely used plant growth retardant (PGR) for producing compact spring flowering bedding plants; however, growers should be aware that it can induce flower bleaching or breaking in flower color.
13.14 - Relearning How to Grow: Substrates
With recent challenges in substrate availability growers must modify their watering, fertility, and growing practices to optimize plant growth.
13.13 - Petunia Purpling Problems
From rooting to finishing, there are a wide range of reasons why petunias may display purple discoloration. However, the location of occurrence and the stage can help diagnose why the discoloration is occurring.
13.11 - Fern-feeding Caterpillars
Are your ferns failing to fill out as they have in past years? The culprit could be the larval stage of the Florida fern moth (Callopistriafloridensis), one of five species of fern moths.
13.10 - Safeguarding Overwintering Structures and Greenhouses from Rodent Infestations
Overwintering structures and heated greenhouses create an ideal habitat for rodents, posing a challenge for growers who must monitor and control rodent activity to protect hardgoods, seeds, and young to finished plants.
13.09 - US Consumer Motivations Driving Native Plant Sales
The following e-GRO Alert discusses US consumers motivations for incorporating native plants into their gardens and landscapes.
13.08 - Sanitation: A Culture to be Established & Nurtured
Description: Sanitation is the process of cleaning an area to protect plant health and staff safety. When sanitation fails, we put at risk the people that work in our operation and the crops that we work so hard to grow. In this Alert, we will discuss why EVERYONE in the company must be involved in the sanitation process.
13.07 - Mastering the Mix with Strategic Crop Groupings
Strategically grouping greenhouse crops based on their environmental or cultural requirements ensures successful growth despite conflicting needs.
13.06 - Perennial Powerhouse: Unlock More with the New PGR Guide
The latest edition of the Plant Growth Regulator Guide for Containerized Herbaceous Perennial Plants is now available.
13.05 - Swish-Swish: Dipping Unrooted Vegetative Cuttings to Reduce Incoming Pest Populations
Dipping unrooted vegetative cuttings in biopesticides has been shown to be effective at reducing whitefly, thrips, and spider mite populations.
13.04 - Ironing Out: Problems in a Petunia Crop
Interveinal chlorosis of the upper foliage is a common problem in petunia production. However, this can be a result of many factors including insufficient iron fertility, high pH, and overwater resulting in iron deficiency symptoms.
13.03 - Mind the Mist: Petunias
During propagation, mist management is the key to quick rooting. Excessive moisture will result in slower rooting and the onset of shoot tip discoloration and necrosis.
13.02 - Phosphorus Has 2 Ps
When phosphorus is deficient, the classical symptom we all learn is lower leaf purpling. With warmer growing temperatures, a different symptomology occurs as lower leaf olive-green spotting on pale leaves. Knowing both types of symptoms will help diagnose a phosphorus deficiency.
13.01 - Quick Check for Spring
Use this quick checklist to help prevent spring season issues.
13.21 - Hydrangea Leaf Distortion: 2024 Sponsors Hydrangea Ringspot Virus confirmed
A recent eGRO alert on “How to Deal with Diagnosis” (https://www.e-gro.org/pdf/2024-13-18.pdf), stressed the importance of looking for symptom patterns and getting an accurate diagnosis for a plant problem.
13.20 - PGRs: Where to Start
Many greenhouse growers regularly use plant growth regulators or retardants (PGRs) to elicit desirable crop responses. Those new to using PGRs should consider their goals and several factors prior to making applications.
13.19 - Biostimulants for Greenhouse Ornamental Crop Production
This article provides an overview of what biostimulants are, how they can improve the quality of greenhouse ornamental crops, and key considerations for choosing and using biostimulant products effectively.
13.18 - How to Deal with Diagnosis
Correctly identifying the cause of a problem is the first step in effective and economic management practices. Learn some tips about how to diagnose the cause of plant problems.
13.17 - Much Ado About (a) Thrips
Managing this new pest partly depends on recognizing it and choosing effective controls, informed by data from recent research specifically targeting this insect
13.16 - Daminozide Dilemmas: Avoiding Flower Bleaching in Spring Bedding Plants
Daminozide is a widely used plant growth retardant (PGR) for producing compact spring flowering bedding plants; however, growers should be aware that it can induce flower bleaching or breaking in flower color.
13.14 - Relearning How to Grow: Substrates
With recent challenges in substrate availability growers must modify their watering, fertility, and growing practices to optimize plant growth.
13.13 - Petunia Purpling Problems
From rooting to finishing, there are a wide range of reasons why petunias may display purple discoloration. However, the location of occurrence and the stage can help diagnose why the discoloration is occurring.
13.11 - Fern-feeding Caterpillars
Are your ferns failing to fill out as they have in past years? The culprit could be the larval stage of the Florida fern moth (Callopistriafloridensis), one of five species of fern moths.
13.10 - Safeguarding Overwintering Structures and Greenhouses from Rodent Infestations
Overwintering structures and heated greenhouses create an ideal habitat for rodents, posing a challenge for growers who must monitor and control rodent activity to protect hardgoods, seeds, and young to finished plants.
13.09 - US Consumer Motivations Driving Native Plant Sales
The following e-GRO Alert discusses US consumers motivations for incorporating native plants into their gardens and landscapes.
13.08 - Sanitation: A Culture to be Established & Nurtured
Description: Sanitation is the process of cleaning an area to protect plant health and staff safety. When sanitation fails, we put at risk the people that work in our operation and the crops that we work so hard to grow. In this Alert, we will discuss why EVERYONE in the company must be involved in the sanitation process.
13.07 - Mastering the Mix with Strategic Crop Groupings
Strategically grouping greenhouse crops based on their environmental or cultural requirements ensures successful growth despite conflicting needs.
13.06 - Perennial Powerhouse: Unlock More with the New PGR Guide
The latest edition of the Plant Growth Regulator Guide for Containerized Herbaceous Perennial Plants is now available.
13.05 - Swish-Swish: Dipping Unrooted Vegetative Cuttings to Reduce Incoming Pest Populations
Dipping unrooted vegetative cuttings in biopesticides has been shown to be effective at reducing whitefly, thrips, and spider mite populations.
13.04 - Ironing Out: Problems in a Petunia Crop
Interveinal chlorosis of the upper foliage is a common problem in petunia production. However, this can be a result of many factors including insufficient iron fertility, high pH, and overwater resulting in iron deficiency symptoms.
13.03 - Mind the Mist: Petunias
During propagation, mist management is the key to quick rooting. Excessive moisture will result in slower rooting and the onset of shoot tip discoloration and necrosis.
13.02 - Phosphorus Has 2 Ps
When phosphorus is deficient, the classical symptom we all learn is lower leaf purpling. With warmer growing temperatures, a different symptomology occurs as lower leaf olive-green spotting on pale leaves. Knowing both types of symptoms will help diagnose a phosphorus deficiency.
13.01 - Quick Check for Spring
Use this quick checklist to help prevent spring season issues.
12.42 - Traditional and Digital Diagnostic Tools of the Trade
This alert covers commonly used tools used to examine and identify insect pests and disease organisms of horticultural crops.
12.41 - Micronutrient Madness: Basil
Lower leaf necrosis can occur as a result of excessive micronutrient applications. To confirm the diagnosis of a toxic condition, a tissue test is necessary.
12.40 - Geranium TSWV
Three geranium plants were observed with ring spots and upper-leaf mottling. These were typical signs of a viral infection, but the occurrence of a virus is uncommon.
12.39 - Going Viral
This Alert is a photographic guide to viruses found on a wide array species during the 2023 production season and will aid in the identification of these problems.
12.38 - Begonias Gone Viral
The host range for both impatiens necrotic spot virus (INSV) and tomato spotted wilt virus (TSWV) is vast. Just as the possible hosts vary, so do the typical signs of the virus. This Alert focuses on wax, dragonwing and non-stop begonias and illustrates the wide variation of how the disease displays itself in these three related species.
12.37 - Squirrelly Snapdragon Growth
Problematic snapdragon plants with spindly growth, blotchy yellow leaf batches, and lower leaf drop on only one cultivar series were observed. Downy mildew was identified as the cause.
12.36 - Mimics: Mexican Sunflower
Upon inspection of some problematic Mexican sunflower plants with lower leaf interveinal chlorosis and purplish-black coloration, the initial diagnosis pointed towards a direction, while the data from the leaf tissue and substrate samples supported a different conclusion. This e-GRO Alert points out the importance of supportive data and knowing possible problems when diagnosing plant disorders.
12.35 - The Mitey Marigold
French marigolds offer excellent color and can be grown in a wide range of USDA hardiness zones. While French marigolds grow well in warm conditions such as greenhouses, spider mites love these same conditions.
12.34 - Ironing Out Problems in Pansies
Interveinal chlorosis of the upper foliage is a common problem in pansy production. However, this can be a result of many factors including insufficient iron fertility, high pH, and overwater resulting in iron deficiency symptoms.
12.33 - Verifying the Proper Function of Fertilizer Injectors
Providing the right amount of fertilizer is fundamental to achieve high quality crops. In this Alert, we present two methods to assess if the fertilizer injector is working properly.
12.32 - A Sticky Subject: Yellow Sticky Cards
In this Alert, we provide an overview of how to use and monitor yellow sticky cards to monitor pests in the greenhouse.
12.31 - A Quick Review of Poinsettia Powdery Mildew
Powdery mildew can spread rapidly once the conditions are favorable and an epidemic can be devastating to a poinsettia crop. The key is finding it early and staying on top of management.
12.30 - Using Plant Benefit Information to Engage Customers
This e-GRO Alert provides insights gained from research on U.S. consumer responses to plant benefit information in retail garden center promotions.
12.29 - The Slimy Weed of Greenhouse
In this e-GRO alert, growers will learn how to identify and manage Nostoc in the greenhouse production system
12.28 - Who is Benefiting from Online Advertising in the Environmental Horticulture Industry?
This publication highlights the findings of a research article titled “Evaluating the Business and Owner Characteristics Influencing the Adoption of Online Advertising Strategies in the Green Industry” (Torres et al., 2021). Findings addressed different factors impacting green industry firms’ willingness to participate in online advertising and how those factors influenced the amount invested in online advertisements.
12.27 - Plant a Caterpillar Garden!
Last spring my Assistant Entomologist and I were asked to speak about butterflies to a garden group. Before getting on with the business of attracting them, we decided to discuss how to generate more of them (and our moth friends) through plant selection.
12.26 - Common Groundsel: A Problematic Weed Species
In this e-GRO alert, growers will learn how to identify common groundsel in their greenhouses for container production
12.25 - Get the 4-1-1 on Social Media for Garden Retailers
Engaging and inspiring consumers through social media can build trust and loyalty and drive sales.
12.24 - Dahlias: Getting More Popular With People (and Pests)
The popularity of dahlias only seems to increase; our summer and fall tourists snap up irresistible cut flower bouquets from the local farmstands as quickly as they’re produced. But entomologists and plant pathologists also know as popularity in the plant trade rises, associated pests and pathogens often follow.
12.23 - Developing an Emergency Action Plan for Your Greenhouse Operation
Are you prepared in the event of an emergency? Invest time in developing an emergency action plan for your operation –before an accident or natural disaster strikes.
12.22 - Chloromequat chloride-induced chlorosis on osteospermum
Chlorosis can be a concerning thing to see in the greenhouse, since it can be a symptom of a variety of biotic and abiotic disorders. In this Alert, we will look at how excessive chlormequat chloride solution can affect osteospermum.
12.21 - Avoiding Ammonium Toxicity is Easy!
Pansies are selling, so why talk about a production issue that is frequently observed during the winter and early spring? It’s never too late to buy a different fertilizer blend for crops that are prone to ammonium toxicity before you forget.
12.20 - TSWV and INSV on annual bedding plants
Tomato Spotted Wilt Virus (TSWV) and Impatiens Necrotic Spot Virus (INSV) causing light or darkly colored ringspots symptoms were seen on annual bedding plants.
12.19 - Controlling spotted spurge in greenhouse container production
In this e-GRO alert, growers will learn how to identify and manage spotted spurge in their greenhouses for container production
12.18 - Environmental Gardening Practices & Native Plant Purchasers
Consumer interest in native plants and their participation in environmentally friendly gardening practices is discussed.
12.17 - Sunflowers: Insects Like Them Too!
Everyone loves sunny sunflowers, judging from their growing popularity and diversity as a cut flower.
12.16 - The Support Beginning Farmers Need for Adopting New Technologies
This publication illustrates the findings from a study conducted by the author titled Exploring the adoption of technologies among beginning farmers in the specialty crops industry, published in the Journal of Agricultural Finance Review in 2022. The findings show the barriers and opportunities for adopting new technologies.
12.15 - Recognizing and Preventing Phytotoxicity
Sometimes products used for pest or disease management can end up injuring the crops they are meant to help. Learn how to recognize and prevent phytotoxicity from pesticide applications.
12.14 - Chronic Underwatering of Gerbera Daisy
Growth control is a great thing…when it happens on purpose. Inadvertently growing containerized gerbera dry for extended periods of time excessively stunts growth more than desired.
12.13 - Proper Application of Controlled-Release Fertilizers
Controlled-release fertilizers (CRFs) can be either incorporated or top-dressed for containerized crop production. Proper application procedures and methods will determine success.
12.12 - Fusarium crown and stem rot of Echeveria
It is important to accurately identify the cause of plant disease. Fusarium infection of Echeveria causes a "dry rot" that causes yellowing, shriveling, and plant death. Fusarium is also difficult to control.
12.11 - The Pros and Cons of Indoor Plant Production Facilities
The most compelling reason for growing in an indoor plant production facility is the complete control of the growth environment.
12.10 - Wet, Overcast Conditions Leads to Disease Problems
Cold, wet, and overcast conditions have created problems, particularly with Pythium root rot and Botrytis blight, in early spring production of annual flowering plants.
12.09 - Leaf Spot on Calibrachoa
Calibrachoas with a concern of a virus disease were scouted. Thankfully, no virus infection was detected, however Cercospora leaf spot and powdery mildew were instead identified.
12.08 - Improving Rooting Uniformity with Rooting Hormones
Many growers propagate unrooted cuttings, but propagation success varies among species, cultivars, and environmental conditions. Rooting hormones can be used to ensure and improve rooting success of vegetative shoot-tip cuttings.
12.07 - Growing Talent: Creating a Mutually Beneficial Internship Program
Internship programs ensure that there is new talent and passion coming into the floriculture industry and, hopefully, your business.
12.06 - Shasta Daisy: Undifferentiated Basal Growth
Shasta daisy were observed to have a large growth mass near the stem base. This symptom was likely the result of a rhodococcus infection.
12.05 - Stachys byzantina: Sclerotinia (White Mold)
Stachys leaf dieback and upon careful investigation leaves with a pronounced white, cottony growth (mycelium) were observed. Along with the discovery of small, irregular-shaped, black clumps (sclerotia) on the underside of leaves touching the substrate surface, these signs aid in the identification of a Sclerotinia infection.
12.04 - Rudbeckia: Sclerotinia (White Mold)
Rudbeckia plant collapse and leaves with a pronounced white, cottony growth (mycelium) were observed. Along with the discovery of small, irregular-shaped, black clumps (sclerotia) on the underside of leaves touching the substrate surface, these signs aid in the identification of a Sclerotinia infection.
12.03 - PGR Guide for Annuals Published
The latest version of the Plant Growth Regulator Guide for Annuals is now available, a project sponsored by Fine Americas. GrowerTalks subscribers will receive a copy in the mail or use the link in this Alert to obtain a pdf copy.
12.02 - Utilizing Color Psychology in the Greenhouse and Garden Center
Color psychology or the study of how color influences human behavior and feelings can assist with the planning of cropping cycles, creating mixed combination planters, and displays. A great way to adopt color psychology into your growing and retail planning is to implement the 2023 Pantone Color of the Year and spring and summer color palette.
12.01 - (Re)Discovering Floriculture History
The path of discovery can take many twists and turns, and the journey may take multiple years. New online resources help you search and discover historical information that was practically impossible to find before.
11.36 - The Irony of Overwatering
Interveinal chlorosis of the upper foliage can develop based on a number of conditions. Excessive irrigation can limit iron uptake and be the primary factor of inducing deficiency symptoms.
11.35 - Bacterial soft rot causing death of succulents
Bacterial soft rot occurs sporadically in ornamental production, but when it does, it can be very damaging and cause significant crop loss. It is also difficult to control.
11.34 - Did We Need Another Phytophthora? Did Mums Need Another Disease?
Phytophthora chrysanthemi causes stunting, purpling, and death of foliage, on one major branch or the whole plant; root rot is apparent as well.
11.33 - Poinsettia Mosaic Virus (PnMV)
**ALERT AVAILABLE SOON Poinsettias (Euphorbia pulcherrima) with distorted growth and light green mottling amongst leaves and bracts were observed. This Alert describes and provides photos of symptoms caused by poinsettia mosaic virus (PnMV) on poinsettia. To diagnose PnMV, submit whole plant samples to your preferred diagnostic lab.
11.32 - Mites Under Lights
Sweet potatoes are vegetatively propagated from stock plants primarily in the spring for summer planting and prefer warm climates, unfortunately, spider mites love the same conditions.
11.31 - Encountering Eriophyid Mites on Coneflower and Other Ornamentals
What are eriophyid mites? Eriophyid mites (family Eriophyidae) affect a wide variety of plants and are known as gall, blister, bud, or rust mites based on the abnormalities they cause in their host plants.
11.30 - Controlling yellow woodsorrel in greenhouse container production
In this e-GRO alert, growers will learn how to identify and manage yellow woodsorrel in their greenhouses for container production
11.28 - Keep an eye out for Rhizoctonia web blight
Description: Warmer, humid conditions within greenhouses and outdoor production areas, especially as plant canopies close, are prone to web blight caused by the fungus, Rhizoctonia solani. Infection can creep up on you and go unseen until plants collapse.
11.27 - Alternanthera Mosaic Virus (AltMV)
Samples of portulaca showing distorted leaf edges and chlorotic spots were diagnosed with Alternanthera mosaic virus (AltMV).
11.26 - New Guinea Impatiens: Tomato Spotted Wilt Virus (TSWV)
Necrotic spotting and ringspots were observed on while visiting a grower. These symptoms are typical of what occurs with a virus. This Alert will aid in identification of a tomato spotted wilt virus (TSWV) infection.
11.25 - Heat Stress and Injury of High Tunnel Grown Bedding Plants
High tunnel bedding plant production can be successful, yet risky because plants may be exposed to undesirable temperatures. Lengthy exposure to supra-optimal temperatures can cause discoloration of foliage, delay flowering, and plant injury. This Alert highlights heat stress symptomatology of celosia grown under high tunnel conditions.
11.24 - Tarnished plant bug
Among the more frustrating pests for flower growers, tarnished plant bug often arrives suddenly and undetected, until the unpleasant surprise when the damage shows several days later.
11.23 - Identification and Management of Hairy Bittercress in Greenhouses
In this e-GRO alert, growers will learn how to identify and manage hairy bittercress in their greenhouses for container production
11.22 - Hottest Plant Varieties from the 2021 Michigan Plant Trials
MSU and five cooperating young plant growers in the Michigan Garden Plant Tour trialed varieties last summer and chose their best-of-the-best and visitor favorites from the 2021 trials.
11.21 - It’s the Pictures that Got Big: Choosing a Microscope for Business (or Pleasure)
What have you’ve been missing? You can see it under the microscope! Here are simple tips for buying an inexpensive stereoscope for use in your work - or just for fun.
11.20 - Chili Pepper Mild Mottle Virus (CPMMoV)
CPMMoV can cause mottling, flower break, necrotic spots, and/or general stunt and is being seen on calibrachoas this season. Similar to tobacco mosaic virus (TMV), CPMMoV can be spread by handling.
11.19 - Bacterial Blight on Geraniums, again.
Bacterial blight on geraniums (Figure1), caused by Xanthomonas hortorum pv. pelargonii, is back this growing season. In this Alert we will discuss the symptoms of the disease and management options.
11.18 - Recognizing and Preventing Viral Diseases in the Greenhouse.
This alert features key strategies for growers to consider and discuss when managing plant viruses in the greenhouse.
11.17 - Factors Impacting Business and Marketing Strategies Used by Landscape Firms
The following e-GRO Alert highlights factors impacting business strategies and marketing channels used by firms that include landscaping services.
11.16 - Something Different: Leafhoppers in the Greenhouse
About 15 years ago a greenhouse grower contacted me about small (< 3mm) leafhoppers causing pale stippling on rosemary and lavender foliage.
11.15 - 2022 Insect and Disease Management Recommendations.
Each year, Dr. Mary Hausbeck and Dr. Dave Smitley at Michigan State University release updated insecticide, miticide, and fungicide recommendations. Check out this year’s recommendations for greenhouse ornamentals.
11.14 - Blackleg of Geranium
Geranium plants with black stems and leaf petioles, wilt, and overall plant collapse were observed. This Alert describes blackleg of geranium caused by Pythium sp. To diagnose blackleg, submit plant samples to your preferred diagnostic lab.
11.13 - Fusarium wilt of Cyclamen
Not all root and crown rots are the same. Yellowing, wilting foliage on cyclamen could be Fusarium wilt.
11.12 - Pericallis: Diagnosing Lower Leaf Interveinal Chlorosis and Necrosis
Lower leaf interveinal chlorosis and necrotic spotting on pericallis caused by low potassium (K) levels are diagnosed.
11.11 - Gray Mold Prevention Starts with Air Movement
Air movement is critical in greenhouse environments to limit diseases like gray mold. Good air movement and proper ventilation are key practices that should not be ignored.
11.10 - Are there Risks of Working under LED Supplemental Lighting?
There are potential health risks associated with exposure to both solar radiation and electric light sources used for indoor, street, and horticultural lighting applications. Therefore, knowing the risks can help you take precautions.
11.09 - Premature flowering in annual bedding plants
Getting bedding plants into flower for sales is an important part of spring crop production. However, premature flowering is undesirable. There are a few ways to avoid this problem.
11.08 - Jar Test: Determining Fertilizer Solubility and Compatibility
Not all fertilizers are compatible when mixed to formulate stock solutions. Using the jar test will help determine fertilizer compatibility and unpredicted chemical reactions.
11.07 - Coleus Insect Photo Guide
This e-GRO Alert provides a photographic guide to coleus insects.
11.06 - Coleus Disease Photo Guide
This e-GRO Alert provides a photographic guide to coleus diseases.
11.05 - Coleus Physiological Disorder Photo Guide
This e-GRO Alert provides a photographic guide to coleus physiological disorders.
11.04 - Coleus Nutritional Disorder Photo Guide
This e-GRO Alert provides a photographic guide to coleus nutritional disorders.
11.03 - Hitting the IBA Sweet Spot to Improve Rooting
The use of IBA improves rooting efficiency, but too much can be detrimental. This Alert helps to diagnose excessive rates.
11.02 - Plant Growth Regulator Guide for Herbaceous Perennials Update
The latest edition of the Plant Growth Regulator Guide for Containerized Herbaceous Perennial Plants is now available. Thanks to the sponsor, Fine Americas, Inc., growers can download a free copy online and/or subscribers of GrowerTalks will receive a copy in the mail.
11.01 - Cheers to Ten Years!
Electronic Grower Resources Online (e-GRO) is beginning its 11th season in 2022.
13.21 - Hydrangea Leaf Distortion: 2024 Sponsors Hydrangea Ringspot Virus confirmed
A recent eGRO alert on “How to Deal with Diagnosis” (https://www.e-gro.org/pdf/2024-13-18.pdf), stressed the importance of looking for symptom patterns and getting an accurate diagnosis for a plant problem.
13.20 - PGRs: Where to Start
Many greenhouse growers regularly use plant growth regulators or retardants (PGRs) to elicit desirable crop responses. Those new to using PGRs should consider their goals and several factors prior to making applications.
13.19 - Biostimulants for Greenhouse Ornamental Crop Production
This article provides an overview of what biostimulants are, how they can improve the quality of greenhouse ornamental crops, and key considerations for choosing and using biostimulant products effectively.
13.18 - How to Deal with Diagnosis
Correctly identifying the cause of a problem is the first step in effective and economic management practices. Learn some tips about how to diagnose the cause of plant problems.
13.17 - Much Ado About (a) Thrips
Managing this new pest partly depends on recognizing it and choosing effective controls, informed by data from recent research specifically targeting this insect
13.16 - Daminozide Dilemmas: Avoiding Flower Bleaching in Spring Bedding Plants
Daminozide is a widely used plant growth retardant (PGR) for producing compact spring flowering bedding plants; however, growers should be aware that it can induce flower bleaching or breaking in flower color.
13.14 - Relearning How to Grow: Substrates
With recent challenges in substrate availability growers must modify their watering, fertility, and growing practices to optimize plant growth.
13.13 - Petunia Purpling Problems
From rooting to finishing, there are a wide range of reasons why petunias may display purple discoloration. However, the location of occurrence and the stage can help diagnose why the discoloration is occurring.
13.11 - Fern-feeding Caterpillars
Are your ferns failing to fill out as they have in past years? The culprit could be the larval stage of the Florida fern moth (Callopistriafloridensis), one of five species of fern moths.
13.10 - Safeguarding Overwintering Structures and Greenhouses from Rodent Infestations
Overwintering structures and heated greenhouses create an ideal habitat for rodents, posing a challenge for growers who must monitor and control rodent activity to protect hardgoods, seeds, and young to finished plants.
13.09 - US Consumer Motivations Driving Native Plant Sales
The following e-GRO Alert discusses US consumers motivations for incorporating native plants into their gardens and landscapes.
13.08 - Sanitation: A Culture to be Established & Nurtured
Description: Sanitation is the process of cleaning an area to protect plant health and staff safety. When sanitation fails, we put at risk the people that work in our operation and the crops that we work so hard to grow. In this Alert, we will discuss why EVERYONE in the company must be involved in the sanitation process.
13.07 - Mastering the Mix with Strategic Crop Groupings
Strategically grouping greenhouse crops based on their environmental or cultural requirements ensures successful growth despite conflicting needs.
13.06 - Perennial Powerhouse: Unlock More with the New PGR Guide
The latest edition of the Plant Growth Regulator Guide for Containerized Herbaceous Perennial Plants is now available.
13.05 - Swish-Swish: Dipping Unrooted Vegetative Cuttings to Reduce Incoming Pest Populations
Dipping unrooted vegetative cuttings in biopesticides has been shown to be effective at reducing whitefly, thrips, and spider mite populations.
13.04 - Ironing Out: Problems in a Petunia Crop
Interveinal chlorosis of the upper foliage is a common problem in petunia production. However, this can be a result of many factors including insufficient iron fertility, high pH, and overwater resulting in iron deficiency symptoms.
13.03 - Mind the Mist: Petunias
During propagation, mist management is the key to quick rooting. Excessive moisture will result in slower rooting and the onset of shoot tip discoloration and necrosis.
13.02 - Phosphorus Has 2 Ps
When phosphorus is deficient, the classical symptom we all learn is lower leaf purpling. With warmer growing temperatures, a different symptomology occurs as lower leaf olive-green spotting on pale leaves. Knowing both types of symptoms will help diagnose a phosphorus deficiency.
13.01 - Quick Check for Spring
Use this quick checklist to help prevent spring season issues.
12.42 - Traditional and Digital Diagnostic Tools of the Trade
This alert covers commonly used tools used to examine and identify insect pests and disease organisms of horticultural crops.
12.41 - Micronutrient Madness: Basil
Lower leaf necrosis can occur as a result of excessive micronutrient applications. To confirm the diagnosis of a toxic condition, a tissue test is necessary.
12.40 - Geranium TSWV
Three geranium plants were observed with ring spots and upper-leaf mottling. These were typical signs of a viral infection, but the occurrence of a virus is uncommon.
12.39 - Going Viral
This Alert is a photographic guide to viruses found on a wide array species during the 2023 production season and will aid in the identification of these problems.
12.38 - Begonias Gone Viral
The host range for both impatiens necrotic spot virus (INSV) and tomato spotted wilt virus (TSWV) is vast. Just as the possible hosts vary, so do the typical signs of the virus. This Alert focuses on wax, dragonwing and non-stop begonias and illustrates the wide variation of how the disease displays itself in these three related species.
12.37 - Squirrelly Snapdragon Growth
Problematic snapdragon plants with spindly growth, blotchy yellow leaf batches, and lower leaf drop on only one cultivar series were observed. Downy mildew was identified as the cause.
12.36 - Mimics: Mexican Sunflower
Upon inspection of some problematic Mexican sunflower plants with lower leaf interveinal chlorosis and purplish-black coloration, the initial diagnosis pointed towards a direction, while the data from the leaf tissue and substrate samples supported a different conclusion. This e-GRO Alert points out the importance of supportive data and knowing possible problems when diagnosing plant disorders.
12.35 - The Mitey Marigold
French marigolds offer excellent color and can be grown in a wide range of USDA hardiness zones. While French marigolds grow well in warm conditions such as greenhouses, spider mites love these same conditions.
12.34 - Ironing Out Problems in Pansies
Interveinal chlorosis of the upper foliage is a common problem in pansy production. However, this can be a result of many factors including insufficient iron fertility, high pH, and overwater resulting in iron deficiency symptoms.
12.33 - Verifying the Proper Function of Fertilizer Injectors
Providing the right amount of fertilizer is fundamental to achieve high quality crops. In this Alert, we present two methods to assess if the fertilizer injector is working properly.
12.32 - A Sticky Subject: Yellow Sticky Cards
In this Alert, we provide an overview of how to use and monitor yellow sticky cards to monitor pests in the greenhouse.
12.31 - A Quick Review of Poinsettia Powdery Mildew
Powdery mildew can spread rapidly once the conditions are favorable and an epidemic can be devastating to a poinsettia crop. The key is finding it early and staying on top of management.
12.30 - Using Plant Benefit Information to Engage Customers
This e-GRO Alert provides insights gained from research on U.S. consumer responses to plant benefit information in retail garden center promotions.
12.29 - The Slimy Weed of Greenhouse
In this e-GRO alert, growers will learn how to identify and manage Nostoc in the greenhouse production system
12.28 - Who is Benefiting from Online Advertising in the Environmental Horticulture Industry?
This publication highlights the findings of a research article titled “Evaluating the Business and Owner Characteristics Influencing the Adoption of Online Advertising Strategies in the Green Industry” (Torres et al., 2021). Findings addressed different factors impacting green industry firms’ willingness to participate in online advertising and how those factors influenced the amount invested in online advertisements.
12.27 - Plant a Caterpillar Garden!
Last spring my Assistant Entomologist and I were asked to speak about butterflies to a garden group. Before getting on with the business of attracting them, we decided to discuss how to generate more of them (and our moth friends) through plant selection.
12.26 - Common Groundsel: A Problematic Weed Species
In this e-GRO alert, growers will learn how to identify common groundsel in their greenhouses for container production
12.25 - Get the 4-1-1 on Social Media for Garden Retailers
Engaging and inspiring consumers through social media can build trust and loyalty and drive sales.
12.24 - Dahlias: Getting More Popular With People (and Pests)
The popularity of dahlias only seems to increase; our summer and fall tourists snap up irresistible cut flower bouquets from the local farmstands as quickly as they’re produced. But entomologists and plant pathologists also know as popularity in the plant trade rises, associated pests and pathogens often follow.
12.23 - Developing an Emergency Action Plan for Your Greenhouse Operation
Are you prepared in the event of an emergency? Invest time in developing an emergency action plan for your operation –before an accident or natural disaster strikes.
12.22 - Chloromequat chloride-induced chlorosis on osteospermum
Chlorosis can be a concerning thing to see in the greenhouse, since it can be a symptom of a variety of biotic and abiotic disorders. In this Alert, we will look at how excessive chlormequat chloride solution can affect osteospermum.
12.21 - Avoiding Ammonium Toxicity is Easy!
Pansies are selling, so why talk about a production issue that is frequently observed during the winter and early spring? It’s never too late to buy a different fertilizer blend for crops that are prone to ammonium toxicity before you forget.
12.20 - TSWV and INSV on annual bedding plants
Tomato Spotted Wilt Virus (TSWV) and Impatiens Necrotic Spot Virus (INSV) causing light or darkly colored ringspots symptoms were seen on annual bedding plants.
12.19 - Controlling spotted spurge in greenhouse container production
In this e-GRO alert, growers will learn how to identify and manage spotted spurge in their greenhouses for container production
12.18 - Environmental Gardening Practices & Native Plant Purchasers
Consumer interest in native plants and their participation in environmentally friendly gardening practices is discussed.
12.17 - Sunflowers: Insects Like Them Too!
Everyone loves sunny sunflowers, judging from their growing popularity and diversity as a cut flower.
12.16 - The Support Beginning Farmers Need for Adopting New Technologies
This publication illustrates the findings from a study conducted by the author titled Exploring the adoption of technologies among beginning farmers in the specialty crops industry, published in the Journal of Agricultural Finance Review in 2022. The findings show the barriers and opportunities for adopting new technologies.
12.15 - Recognizing and Preventing Phytotoxicity
Sometimes products used for pest or disease management can end up injuring the crops they are meant to help. Learn how to recognize and prevent phytotoxicity from pesticide applications.
12.14 - Chronic Underwatering of Gerbera Daisy
Growth control is a great thing…when it happens on purpose. Inadvertently growing containerized gerbera dry for extended periods of time excessively stunts growth more than desired.
12.13 - Proper Application of Controlled-Release Fertilizers
Controlled-release fertilizers (CRFs) can be either incorporated or top-dressed for containerized crop production. Proper application procedures and methods will determine success.
12.12 - Fusarium crown and stem rot of Echeveria
It is important to accurately identify the cause of plant disease. Fusarium infection of Echeveria causes a "dry rot" that causes yellowing, shriveling, and plant death. Fusarium is also difficult to control.
12.11 - The Pros and Cons of Indoor Plant Production Facilities
The most compelling reason for growing in an indoor plant production facility is the complete control of the growth environment.
12.10 - Wet, Overcast Conditions Leads to Disease Problems
Cold, wet, and overcast conditions have created problems, particularly with Pythium root rot and Botrytis blight, in early spring production of annual flowering plants.
12.09 - Leaf Spot on Calibrachoa
Calibrachoas with a concern of a virus disease were scouted. Thankfully, no virus infection was detected, however Cercospora leaf spot and powdery mildew were instead identified.
12.08 - Improving Rooting Uniformity with Rooting Hormones
Many growers propagate unrooted cuttings, but propagation success varies among species, cultivars, and environmental conditions. Rooting hormones can be used to ensure and improve rooting success of vegetative shoot-tip cuttings.
12.07 - Growing Talent: Creating a Mutually Beneficial Internship Program
Internship programs ensure that there is new talent and passion coming into the floriculture industry and, hopefully, your business.
12.06 - Shasta Daisy: Undifferentiated Basal Growth
Shasta daisy were observed to have a large growth mass near the stem base. This symptom was likely the result of a rhodococcus infection.
12.05 - Stachys byzantina: Sclerotinia (White Mold)
Stachys leaf dieback and upon careful investigation leaves with a pronounced white, cottony growth (mycelium) were observed. Along with the discovery of small, irregular-shaped, black clumps (sclerotia) on the underside of leaves touching the substrate surface, these signs aid in the identification of a Sclerotinia infection.
12.04 - Rudbeckia: Sclerotinia (White Mold)
Rudbeckia plant collapse and leaves with a pronounced white, cottony growth (mycelium) were observed. Along with the discovery of small, irregular-shaped, black clumps (sclerotia) on the underside of leaves touching the substrate surface, these signs aid in the identification of a Sclerotinia infection.
12.03 - PGR Guide for Annuals Published
The latest version of the Plant Growth Regulator Guide for Annuals is now available, a project sponsored by Fine Americas. GrowerTalks subscribers will receive a copy in the mail or use the link in this Alert to obtain a pdf copy.
12.02 - Utilizing Color Psychology in the Greenhouse and Garden Center
Color psychology or the study of how color influences human behavior and feelings can assist with the planning of cropping cycles, creating mixed combination planters, and displays. A great way to adopt color psychology into your growing and retail planning is to implement the 2023 Pantone Color of the Year and spring and summer color palette.
12.01 - (Re)Discovering Floriculture History
The path of discovery can take many twists and turns, and the journey may take multiple years. New online resources help you search and discover historical information that was practically impossible to find before.
11.36 - The Irony of Overwatering
Interveinal chlorosis of the upper foliage can develop based on a number of conditions. Excessive irrigation can limit iron uptake and be the primary factor of inducing deficiency symptoms.
11.35 - Bacterial soft rot causing death of succulents
Bacterial soft rot occurs sporadically in ornamental production, but when it does, it can be very damaging and cause significant crop loss. It is also difficult to control.
11.34 - Did We Need Another Phytophthora? Did Mums Need Another Disease?
Phytophthora chrysanthemi causes stunting, purpling, and death of foliage, on one major branch or the whole plant; root rot is apparent as well.
11.33 - Poinsettia Mosaic Virus (PnMV)
**ALERT AVAILABLE SOON Poinsettias (Euphorbia pulcherrima) with distorted growth and light green mottling amongst leaves and bracts were observed. This Alert describes and provides photos of symptoms caused by poinsettia mosaic virus (PnMV) on poinsettia. To diagnose PnMV, submit whole plant samples to your preferred diagnostic lab.
11.32 - Mites Under Lights
Sweet potatoes are vegetatively propagated from stock plants primarily in the spring for summer planting and prefer warm climates, unfortunately, spider mites love the same conditions.
11.31 - Encountering Eriophyid Mites on Coneflower and Other Ornamentals
What are eriophyid mites? Eriophyid mites (family Eriophyidae) affect a wide variety of plants and are known as gall, blister, bud, or rust mites based on the abnormalities they cause in their host plants.
11.30 - Controlling yellow woodsorrel in greenhouse container production
In this e-GRO alert, growers will learn how to identify and manage yellow woodsorrel in their greenhouses for container production
11.28 - Keep an eye out for Rhizoctonia web blight
Description: Warmer, humid conditions within greenhouses and outdoor production areas, especially as plant canopies close, are prone to web blight caused by the fungus, Rhizoctonia solani. Infection can creep up on you and go unseen until plants collapse.
11.27 - Alternanthera Mosaic Virus (AltMV)
Samples of portulaca showing distorted leaf edges and chlorotic spots were diagnosed with Alternanthera mosaic virus (AltMV).
11.26 - New Guinea Impatiens: Tomato Spotted Wilt Virus (TSWV)
Necrotic spotting and ringspots were observed on while visiting a grower. These symptoms are typical of what occurs with a virus. This Alert will aid in identification of a tomato spotted wilt virus (TSWV) infection.
11.25 - Heat Stress and Injury of High Tunnel Grown Bedding Plants
High tunnel bedding plant production can be successful, yet risky because plants may be exposed to undesirable temperatures. Lengthy exposure to supra-optimal temperatures can cause discoloration of foliage, delay flowering, and plant injury. This Alert highlights heat stress symptomatology of celosia grown under high tunnel conditions.
11.24 - Tarnished plant bug
Among the more frustrating pests for flower growers, tarnished plant bug often arrives suddenly and undetected, until the unpleasant surprise when the damage shows several days later.
11.23 - Identification and Management of Hairy Bittercress in Greenhouses
In this e-GRO alert, growers will learn how to identify and manage hairy bittercress in their greenhouses for container production
11.22 - Hottest Plant Varieties from the 2021 Michigan Plant Trials
MSU and five cooperating young plant growers in the Michigan Garden Plant Tour trialed varieties last summer and chose their best-of-the-best and visitor favorites from the 2021 trials.
11.21 - It’s the Pictures that Got Big: Choosing a Microscope for Business (or Pleasure)
What have you’ve been missing? You can see it under the microscope! Here are simple tips for buying an inexpensive stereoscope for use in your work - or just for fun.
11.20 - Chili Pepper Mild Mottle Virus (CPMMoV)
CPMMoV can cause mottling, flower break, necrotic spots, and/or general stunt and is being seen on calibrachoas this season. Similar to tobacco mosaic virus (TMV), CPMMoV can be spread by handling.
11.19 - Bacterial Blight on Geraniums, again.
Bacterial blight on geraniums (Figure1), caused by Xanthomonas hortorum pv. pelargonii, is back this growing season. In this Alert we will discuss the symptoms of the disease and management options.
11.18 - Recognizing and Preventing Viral Diseases in the Greenhouse.
This alert features key strategies for growers to consider and discuss when managing plant viruses in the greenhouse.
11.17 - Factors Impacting Business and Marketing Strategies Used by Landscape Firms
The following e-GRO Alert highlights factors impacting business strategies and marketing channels used by firms that include landscaping services.
11.16 - Something Different: Leafhoppers in the Greenhouse
About 15 years ago a greenhouse grower contacted me about small (< 3mm) leafhoppers causing pale stippling on rosemary and lavender foliage.
11.15 - 2022 Insect and Disease Management Recommendations.
Each year, Dr. Mary Hausbeck and Dr. Dave Smitley at Michigan State University release updated insecticide, miticide, and fungicide recommendations. Check out this year’s recommendations for greenhouse ornamentals.
11.14 - Blackleg of Geranium
Geranium plants with black stems and leaf petioles, wilt, and overall plant collapse were observed. This Alert describes blackleg of geranium caused by Pythium sp. To diagnose blackleg, submit plant samples to your preferred diagnostic lab.
11.13 - Fusarium wilt of Cyclamen
Not all root and crown rots are the same. Yellowing, wilting foliage on cyclamen could be Fusarium wilt.
11.12 - Pericallis: Diagnosing Lower Leaf Interveinal Chlorosis and Necrosis
Lower leaf interveinal chlorosis and necrotic spotting on pericallis caused by low potassium (K) levels are diagnosed.
11.11 - Gray Mold Prevention Starts with Air Movement
Air movement is critical in greenhouse environments to limit diseases like gray mold. Good air movement and proper ventilation are key practices that should not be ignored.
11.10 - Are there Risks of Working under LED Supplemental Lighting?
There are potential health risks associated with exposure to both solar radiation and electric light sources used for indoor, street, and horticultural lighting applications. Therefore, knowing the risks can help you take precautions.
11.09 - Premature flowering in annual bedding plants
Getting bedding plants into flower for sales is an important part of spring crop production. However, premature flowering is undesirable. There are a few ways to avoid this problem.
11.08 - Jar Test: Determining Fertilizer Solubility and Compatibility
Not all fertilizers are compatible when mixed to formulate stock solutions. Using the jar test will help determine fertilizer compatibility and unpredicted chemical reactions.
11.07 - Coleus Insect Photo Guide
This e-GRO Alert provides a photographic guide to coleus insects.
11.06 - Coleus Disease Photo Guide
This e-GRO Alert provides a photographic guide to coleus diseases.
11.05 - Coleus Physiological Disorder Photo Guide
This e-GRO Alert provides a photographic guide to coleus physiological disorders.
11.04 - Coleus Nutritional Disorder Photo Guide
This e-GRO Alert provides a photographic guide to coleus nutritional disorders.
11.03 - Hitting the IBA Sweet Spot to Improve Rooting
The use of IBA improves rooting efficiency, but too much can be detrimental. This Alert helps to diagnose excessive rates.
11.02 - Plant Growth Regulator Guide for Herbaceous Perennials Update
The latest edition of the Plant Growth Regulator Guide for Containerized Herbaceous Perennial Plants is now available. Thanks to the sponsor, Fine Americas, Inc., growers can download a free copy online and/or subscribers of GrowerTalks will receive a copy in the mail.
11.01 - Cheers to Ten Years!
Electronic Grower Resources Online (e-GRO) is beginning its 11th season in 2022.
10.38 - Pansy problems: Leaf spot, powdery mildew, and Myrothecium crown rot
Pansies and violas are affected by numerous plant diseases including black root rot, Pythium root rot, powdery mildew, Botrytis blight, and Cercosporaleaf spot. During the winter and spring of 2020, there was also a major problem with Myrothecium crown rot.
10.37 - Unusual Leaf Spot on Poinsettia
While not commonly encountered on poinsettias, Corynespora cassiicola can cause brown leaf spots on leaves and bracts in conditions of high moisture and high humidity.
10.36 - Poinsettia Leaf and Stem Abnormalities
Given that poinsettias are propagated during the hottest months of the year and have a very long production time, they are prone to several pathogens, pests, and physiological disorders.
10.34 - Dodder (Cuscuta spp.): Orange, spaghetti-like growth
Dodder is a parasitic weed with orange, spaghetti-like growth that entwines around plants.
10.33 - Ornamental Cabbage and Kale Water Stress
Excessive wilting of the plants will result in lower leaf yellow and leaf drop.
10.32 - Ornamental Cabbage and Kale Coloration Tips
Coloration of ornamental cabbage and kale is primarily influenced by temperature. A few production practices can help enhance the intensity of coloration, but discontinuing fertilization is not one of them.
10.31 - Summer Weather Patterns Can Influence Irrigation Water Quality
Weather conditions and drought can affect the quality of your irrigation water. Increased alkalinity levels in your irrigation water may be linked to water use.
10.30 - Root Rot in Garden Mums
Small and off-color mums may be a sign of root rot.
10.28 - Garden Mums: Crown Buds Induced by Cool Night Temperatures
Fall garden mum production typically occurs outdoors exposing plants to seasonal environmental conditions. When plants are exposed to several nights of <60 °F (<15.5 °C), premature bud formation or crown buds can be induced.
10.27 - The green you do not want in the greenhouse: Algae
Brief description: A review about practices and products to control algae in greenhouses.
10.26 - White Rust on Portulaca
White rust is not a true rust nor a fungal disease. It is an oomycete disease, and it was recently seen infecting moss-rose purslane (Portulaca grandiflora) in hanging baskets.
10.25 - Taking a More Holistic Approach to Fungus Gnat Management
Fungus gnats can impact crop quality and spread Pythium in greenhouses
10.24 - Pandemic Assistance Programs for Greenhouses and Nurseries
Nearly all floriculture and nursery operations have been impacted by the pandemic. Learn more about USDA programs that can assist producers in challenging times.
10.23 - Leaf-Curling Plum Aphid: A Pest to Watch
Leaf-curling plum aphid, Brachycaudus helichrysi, can cause distortion, stunting of new growth on plants in the Asteraceae.
10.22 - White Mold (Sclerotinia) on Coleus
Description: Coleus plants with white cottony-like growth, stem and leaf rot, and small, hard, black sclerotia were observed. This Alert describes and provides photos of symptoms observed on coleus caused by white mold (Sclerotinia sp.) also referred to as Sclerotinia stem rot or cottony soft rot. To diagnose white mold, submit plant samples to your preferred diagnostic lab.
10.21 - Scouting and Treatment of Gray Mold in Greenhouse Crops
Peak color in the greenhouse coincides with cloudy, damp weather that creates a favorable environment for the fungus Botrytis cinerea, which causes gray mold on many greenhouse ornamentals. This Alert provides tips for scouting and management of gray mold and gives an example fungicide treatment plan for when disease pressure is high.
10.20 - Begonia and Vinca Sensitivity to Paclobutrazol
Plant growth regulators (PGRs) can be successfully used to control growth or induce lateral branching of many bedding plant species, but some may be ‘sensitive’ to the PGR active ingredient. This Alert demonstrates PGR sensitivity for fibrous begonia and vinca where an accidental paclobutrazol drench application resulted in stunted plants, chlorotic (yellowing) leaves, and black spotting.
10.19 - Prevent Chilling Injury
The pandemic, coupled with the cold winter has consumers demanding annuals, herb, and vegetable transplants weeks before the last average frost date. As growers, you obviously want to cash in and take advantage of these impulse purchases. But we all know this is risky! What can you do to prevent losses during those unpredictable cold snaps that occur in April and even into May? In this alert, we will provide some tips on how to protect your crops and provide you with a list of cold hardy plants you should be selling.
10.18 - GR Drenches for Growth Control
Trying to control the growth of all your different spring crops can be a challenge. With so much diversity in our greenhouses, heads can spin trying to keep growth regulated effectively and efficiently. Using PGR drenches can help you this spring, and this Alert will focus on how to do it effectively.
10.17 - Lily Basal Rot
Lily basal rot caused by Fusarium oxysporum f. sp. lilii can cause crop losses in Easter Lilies.
10.16 - Plant Disease Resistance, Reviewed
Defining and understanding plant resistance, susceptibility, immunity.
10.15 - Troubleshooting Ipomoea
Warm season annuals such as ipomoea can be challenged with cloudy weather.
10.14 - Ask an Entomologist
With the pandemic has come even greater demand for diagnostic lab support. Read about some recent issues and what some entomologists do to support our horticulture industries.
10.13 - Bacterial leaf spot diseases are prevalent in wet greenhouses
Wet, humid, overcast weather outside favors plant disease development inside greenhouses because plant foliage and soil remain wet for extended periods of time. Plant wetness within warm greenhouses coupled with young, succulent seedlings and cuttings in production is a recipe for disease development, particularly bacterial leaf spots diseases, which have been widely seen within greenhouses affecting bedding and foliage plants.
10.12 - Cashing in on the Top Four Gardening Motivations of 2020
The spring of 2021 is here! During 2020, despite a very difficult start, many plant retailers had an excellent year – even record-breaking. Why?
10.11 - Interpreting Water Quality Analysis Reports
The quality of irrigation water is crucial to develop nutrient programs that are compatible with the crops’ needs. In this Alert, we will discuss how to interpret the water quality analysis reports to evaluate chemical aspects of water quality that affect nutrient programs.
10.10 - PourThru Method for Large Containerized Crops
The PourThru method is a great procedure to determine the nutritional status of containerized crops. This Alert outlines the steps need to perform a PourThru on larger containers for mix combination planters, herbaceous perennials, and nursery and specialty crops.
10.09 - Sampling Irrigation Water for Routine Lab Analysis
Irrigation sampling is an important nutrient monitoring practice to determine water quality such as pH, electrical conductivity (EC), alkalinity, and available dissolved nutrients. Assessing irrigation water quality will help refine alkalinity management and fertility programs and define limited or excessive nutrients for the appropriate corrective procedure.
10.08 - _Elevated EC Symptomology
Lower leaf necrosis can develop in stevia if the substrate electrical conductivity (EC) is elevated.
10.07 - Stevia: High Substrate pH
Stevia can develop interveinal chlorosis of the upper foliage if the substrate pH is too high.
10.06 - Calonectria root, crown, and cutting rots are less common, but just as damaging
Besides the more common pathogens causing root disease in greenhouse crops, there are other lesser known but equally destructive pathogens affecting specific crops. One example is Calonectria spathiphylli that causes root and petiole rot of Spathiphyllum. Other Calonectria sp. cause root, crown, and cutting rots on woody and herbaceous plants.
10.05 - Aphids in Unexpected Places
Over the past year I had some interesting samples of and questions about aphids, so as winter transitions to spring I’ll use the opportunity to review some of the less common species we’ve encountered in greenhouses over the years while issuing the standard reminder to watch for early signs and respond while infestations are still small in size and area.
10.04 - Who Said That Pansies Were Easy?
Pansies would seem to be an uncomplicated or easy crop….but then the leaves started to yellow…..
10.03 - Powdery Mildew on Succulents Is Not What You Would Expect
Powdery mildew on succulents can appear more like sun scald or edema. In this alert, we will show you what to look for and the fungicides labeled to treat powdery mildew. Remember, when in doubt, submit a sample to a diagnostic lab for confirmation.
10.02 - PGR Guide for Annuals
The 72-page Plant Growth Regulator Guide for Annuals publication has been updated for the 2021-2022 season.
10.01 - Sampling Substrates for Routine or Diagnostic Lab Analysis
Substrate sampling for routine or diagnostic lab analysis is an important nutrient monitoring practice to assess substrate chemical properties including pH, soluble salts, and nutrient status.
