Identifying white mold in tomato production

White mold, or timber rot, is caused by the soil-borne fungal pathogen, Sclerotinia sclerotiorum.

High tunnel tomato plant

High tunnel tomato plant with main stem infected by white mold.

The photo on right shows a high tunnel tomato plant with main stem infected by white mold. Over time the entire plant will slowly collapse looking similar to a wilt or root rot pathogen as the water supply is cut off to the plant.

White mold is common and once introduced into a field or high tunnel it can very difficult to control. The pathogen produces black sclerotia on the surface and inside infected stems. Sclerotia, if they make their way back into the soil, can survive for years causing significant problems.

Infected stems will turn a light brown color and dry up becoming brittle. If the main stem is infected the entire plant will collapse looking like a wilt or root rot issue.

Under hot, humid conditions white fungal growth will develop on the surface of the stems and in some cases sclerotia will develop on the outside of the stem. Breaking open the stem will reveal numerous black sclerotia.

All infected plants and or plant material need to be removed immediately and disposed of properly. Preventative protectant fungicide programs beginning at flowering will help control white mold. Cool, wet weather and poor air circulation favors disease development.

There are a number of control options for conventional and organic growers listed in Table E-11 in the 2022/2023 mid-Atlantic Commercial Vegetable Production Recommendations Guide.

Tomato stem infected by white hold. Note the fungal growth on the surface of the stem.

Tomato stem infected by white hold. Note the fungal growth on the surface of the stem.

White mold of tomato. Note the black sclerotia developing inside the brittle stems.

White mold of tomato. Note the black sclerotia developing inside the brittle stems.

Identifying and controlling leaf mold in high tunnel & greenhouse tomato production

Leaf mold occasionally appears in high tunnel or greenhouse tomato production in New Jersey. However, under ideal conditions the disease will develop in field-grown crops. The fungus will cause infection under prolonged periods leaf wetness and when relative humidity remains above 85%. If relative humidity is below 85% the disease will not occur. Therefore, the proper venting of high tunnels and greenhouses on a regular basis is important. The pathogen can survive (overwinter) as a saprophyte on crop debris or as sclerotia in the soil. Conidia (spores) of the fungus can also survive up to one year in the soil.

Symptoms of leaf mold on infected tomato plant. Note the bright yellow leaves and the olive-green spores developing on the undersides of leaves.

Symptoms of leaf mold on infected tomato plant. Note bright yellow leaves and olive-green spores developing on undersides of leaves.

[Read more…]

Identifying and controlling botrytis in high tunnel and greenhouse tomato production

Botrytis, or gray mold, caused by the fungus, Botrytis cinerea, can cause significant losses in high tunnel and greenhouse tomato production if not controlled properly. The pathogen can rapidly spread during periods when structures are closed and when relative humidity remains high for long periods of time. This often occurs when outside weather remains cool and damp while heating is needed. Gray mold is favored by temperatures from 64° to 75°F and requires only high humidity (not leaf wetness) to become established. The pathogen has a large host range and once established in an enclosed structure it can be very difficult to control (UMASS). The fungus can survive/overwinter as mycelia or sclerotia in plant debris and in organic soil matter (NCSU).

[Read more…]

Identifying and controlling leaf mold in high tunnel & greenhouse tomato production

Leaf mold occasionally appears in high tunnel or greenhouse tomato production in New Jersey. However, under ideal conditions the disease will develop in field-grown crops. The fungus will cause infection under prolonged periods leaf wetness and when relative humidity remains above 85%. If relative humidity is below 85% the disease will not occur. Therefore, the proper venting of high tunnels and greenhouses on a regular basis is important. The pathogen can survive (overwinter) as a saprophyte on crop debris or as sclerotia in the soil. Conidia (spores) of the fungus can also survive up to one year in the soil.

Symptoms of leaf mold on infected tomato plant. Note the bright yellow leaves and the olive-green spores developing on the undersides of leaves.

Symptoms of leaf mold on infected tomato plant. Note bright yellow leaves and olive-green spores developing on undersides of leaves.

[Read more…]

Identifying white mold in greenhouse & high tunnel tomato production

White mold, or timber rot, is caused by the soil-borne fungal pathogen, Sclerotinia sclerotiorum.

High tunnel tomato plant with main stem infected by white mold

High tunnel tomato plant with main stem infected by white mold.

The photo on right shows a high tunnel tomato plant with main stem infected by white mold. Over time the entire plant will slowly collapse looking similar to a wilt or root rot pathogen as the water supply is cut off to the plant.

White mold is common and once introduced into a field or high tunnel it can very difficult to control. The pathogen produces black sclerotia on the surface and inside infected stems. Sclerotia, if they make their way back into the soil, can survive for years causing significant problems.

Infected stems will turn a light brown color and dry up becoming brittle. If the main stem is infected the entire plant will collapse looking like a wilt or root rot issue.

Under hot, humid conditions white fungal growth will develop on the surface of the stems and in some cases sclerotia will develop on the outside of the stem. Breaking open the stem will reveal numerous black sclerotia.

All infected plants and or plant material need to be removed from the greenhouse or high tunnel immediately and disposed of properly. Preventative protectant fungicide programs beginning at flowering will help control white mold. Cool, wet weather and poor air circulation favors disease development.

There are a number of control options for conventional and organic growers listed in Table E-11 in the 2020/2021 mid-Atlantic Commercial Vegetable Production Recommendations Guide.

Tomato stem infected by white hold. Note the fungal growth on the surface of the stem.

Tomato stem infected by white hold. Note the fungal growth on the surface of the stem.

White mold of tomato. Note the black sclerotia developing inside the brittle stems.

White mold of tomato. Note the black sclerotia developing inside the brittle stems.

COVID-19 Resources for Nursery, Greenhouse, Landscape, Garden Centers, etc.

Please contact Cumberland County Extension Agent Tim Waller if you would like to have an association added to the “Green Industry COVID links PDF”. twaller@njaes.rutgers.edu

 

Defining Essential Businesses

Closing of non-essential retail businesses following New Jersey Executive Orders 107 and 108 have had many NJ green-industries wondering, “what does this mean for my business”.

Many NJ Green-Industries are now considered Essential Businesses (as of 3/24/20, list subject to change).

  • Nurseries
  • Greenhouses
  • Landscaping
  • Garden Centers
  • Farms
  • Farm equipment suppliers
  • Farmer-markets
  • Farms that sell directly to customers
  • Grocery stores
  • Hardware and home improvement stores
  • Livestock feed stores

These businesses can remain open as long as they adhere to the safety guidelines outlined in Executive Order 107 and the CDC recommendations (links in PDF attachment).

The included attachment (PDF) with web-links: has a number of important resources concerning COVID-19 at state and federal levels (click or copy links). East and west coast states have been included, as many nurseries will be shipping throughout those regions. Additionally, web-links to nursery and landscape associations of each state, have been included to serve as a point of reference when shipping in to or out of that state. Contact the local associations for additional clarification if needed. The list is in no way exhaustive as many states have numerous green-industry associations.

Links pertaining to international land border agreements between the USA, and Canada, and Mexico have also been listed.

 

(PDF): Green Industry COVID links PDF 3 30  (Click link. Copy web-address if not working)

 

Quick links to New Jersey Associations:

New Jersey Landscape Contractors Association: https://www.njlca.org/

New Jersey Nursery and Landscape Association: https://www.njnla.org/

New Jersey Green Industry Council: http://njgic.org/

New Jersey Turfgrass Association: https://njta.wildapricot.org/

New Jersey Christmas Tree Growers Association: https://njchristmastrees.org/

New Jersey Farm Bureau: https://njfb.org/

 

BUSINESSES WILL NEED TO FOLLOW SOCIAL DISTANCING PRACTICES.

Business social distancing:

Social distancing for customers will include but limited to, signage for customers to remain 6 feet apart from one another as well as a concerted effort by owners/employees to sanitize frequently used carts, doors, loading equipment, etc.

  • Commonly touched hard surfaces should be routinely disinfected while wearing disposable gloves with 70% alcohol, or other common EPA-registered household disinfectants (diluted bleach instructions below). Soft/porous surfaces should be cleaned with EPA-approved spray/aerosol sanitizers. Any fabric that can be laundered (uniforms, table cloths, etc.) should be done so separately from household laundry. The use of non-clothing linens should be discouraged. For example the use of tablecloths under cash registers is discouraged.

Employee social distancing:

These same efforts must be applied for social distancing amongst employees, including but not limited to, prohibit sharing of vehicles between different work crews or tightly packing single vehicles, routinely sanitizing commonly used tools and equipment, prohibiting congregations around break/lunch areas, etc.

  • Travelers per vehicle should be limited to maximize physical distance between employees/occupants. If possible 1 crew per vehicle for the duration of COVID-19 concerns should be implemented. While conducting business, employee sanitation efforts should be constantly minded. This would include cleaning hard vehicle interiors with disinfectant solutions (70% alcohol, and most common EPA-registered household disinfectants) as well as soft interior surfaces with EPA-approved spray/aerosol sanitizers while wearing disposable gloves. Any fabric that can be laundered (seat covers, work uniform, bibs, etc.) should be done so separately from household laundry.

Diluted household bleach solutions can be used if appropriate for the surface. Follow manufacturer’s instructions for application and proper ventilation. Check to ensure the product is not past its expiration date. Never mix household bleach with ammonia or any other cleanser. Unexpired household bleach will be effective against coronaviruses when properly diluted.

Prepare a bleach solution by mixing:

  • 5 tablespoons (1/3rd cup) bleach per gallon of water or
  • 4 teaspoons bleach per quart of water

Detailed disinfection instructions can be found at the CDC website: https://www.cdc.gov/coronavirus/2019-ncov/prepare/cleaning-disinfection.html

 

Businesses are encouraged to give each employee a letter indicating that the employee works in an industry permitted to continue operations.

Employees reporting to work are permitted to travel to and from their place of business. This would also apply when nursery deliveries or landscapers services are being performed.

 

Ideas to generate more business during COVID-19:

  • Increase social media marketing, targeting local audiences
  • Offer delivery services or order online-pick up at store
  • Generate ‘kits’, of easy to grow plants for a new wave of horticulture enthusiasts
  • Offer online demonstrations or classes, branding your business as top-notch
  • Promote different horticulture techniques that should spur purchases
  • Promote unique plants that the average person has not seen and may take interest

 

In the case of economic disaster:

The Small Business Administration (SBA) has been approved for Economic Injury Disaster Loans, which includes businesses, agricultural cooperatives, and non-profits. Application filing deadline is 12/18/2020.

Applicants may apply online, receive additional disaster assistance information, and download applications at https://disasterloan.sba.gov/ela

Applicants may also call SBA’s Customer Service Center for more information on SBA disaster assistance.

phone: (800) 659-2955

email: disastercustomerservice@sba.gov

 

OTHER IMPORTANT QUICK LINKS:

CDC COVID page: https://www.cdc.gov/coronavirus/2019-ncov/index.html

NJ COVID page: https://covid19.nj.gov/

Inventory or donations of PPE (Executive Order No. 109): https://covid19.nj.gov/ppereport

All current and archived executive orders: https://nj.gov/infobank/eo/056murphy/approved/eo_archive.html

 

 

Stay healthy. Exercise caution on- and off-the-clock!