Organic Farm Advisory

The Plant & Pest Advisory serves NJ growers by reporting on important pests and recommending responses that are grounded in reproducible trials.

Articles in this section contain information helpful to the NJ commercial organic grower.

Sharing organic practice trial results between land-grant universities is a cost effective way to create a common knowledge base built on the strengths of individual programs. In the sidebar, find institutions with programs in organic agriculture which augment knowledge developed at the Rutgers New Jersey Ag Experiment Station.

Rutgers Cooperative Extension Field Guides: These concise guides help with decision making from pre-planting to harvest. For each crop listed, learn what pests to proactively look for as the season progresses, how to look for them, and when to take action.

Field Guide List

Greenhouse Disease Management: Seed Treatments and Transplant Production

Seed Treatment

Seed used in transplant production should be certified ‘clean’ or disease-free. Most commercial seed comes with certification and is pretreated with fungicide. Important diseases such as Bacterial leaf spot of tomato and pepper can cause major problems in transplant production if introduced in the greenhouse, especially if untreated seed is infested. Remember, a small amount of infested seed can be a major source of inoculum in the greenhouse and cause significant problems in the field later in the growing season.

As a rule for any crop, any non-certified or untreated seed should be treated, if applicable, with a Clorox treatment, or with hot water seed treatment, then treated pre-seeding or at seeding with fungicide(s) to help minimize damping-off diseases. Organic and conventional tomato growers who grow a significant number of heirloom vegetables, such as tomatoes, should consider using the hot water seed treatment to help reduce the chances for bacterial problems. Remember, Chlorox simply acts as a surface disinfectant, kllling pathogens that may reside on the surface of the seed. The hot water seed treatment method will also kill potential pathogens within the seed.

Hot Water Seed Treatment Method

Hot water seed treatment is a non-chemical alternative to conventional chlorine treatment which only kills pathogens on the surface of the seed. Heat-treatment done correctly kills pathogens inside the seed as well. If done incorrectly, it may not eradicate pathogens and may reduce germination and vigor. For cole crops, it is especially important to follow treatment protocols as seeds can split.

Seed heat treatment follows a strict time and temperature protocol and is best done with thermostatically controlled water baths. Two baths are required: one for pre-heating, and a second for the effective (pathogen killing) temperature. For cole crops, the initial pre-heating is at 100°F (38°C) for 10 minutes. The effective temperature is 122°F (50°C). Soaking at the effective temperature should be done for 20 minutes for broccoli, cauliflower, collards, kale, and Chinese cabbage, and 25 minutes for Brussels sprouts and cabbage. Immediately after removal from the bath, seeds should be rinsed with cool water to stop the heating process. After that, seeds should be dried on a screen or paper. Pelleted seeds are not recommended for heat treatment. Only treat seed that will be used in the current season.

As an alternative to hot water seed treatment, use 1 part Alcide (sodium chlorite), 1 part lactic acid, and 18 parts water as a seed soak. Treat seed 1-2 minutes and rinse for 5 minutes in running water at room temperature.

For more information on seed treatment methods please see page 124 in the upcoming 2020/2021 Mid-Atlantic Commercial Vegetable Production Recommendations Guide.

Transplant Production

Proper greenhouse sanitation is important for healthy, disease-free vegetable transplant production. Efforts need to be made to keep transplant production greenhouses free of unnecessary plant debris, soils, and weeds which may harbor insect pests and disease.

  • All equipment, benches, flats, plug trays and floors should be properly cleaned and then disinfested prior to use with efforts taken throughout the transplant production season to minimize potential problems.
  • Any weeds in or around the greenhouse structure should be removed prior to and after any production.
  • Any transplant brought into the greenhouse from an outside source needs to be certified ‘clean’, as well as visually inspected for potential insects and diseases once it reaches your location. Suspect plants should not be placed in the greenhouse.

Remember, disinfestants, such as Clorox, Green-Shield, or hydrogen dioxide products (Zerotol – for commercial greenhouses, garden centers and Oxidate – commercial greenhouse and field), kill only what they come into direct contact with so thorough coverage and/or soaking is necessary. The labels do not specify time intervals for specific uses, only to state that surfaces be ‘thoroughly wetted’. Therefore, labels need to be followed precisely for different use patterns (i.e., disinfesting flats vs. floors or benches) to ensure proper dilution ratios. Hydrogen dioxide products work best when diluted with water containing little or no organic matter and in water with a neutral pH. There are a number conventional and organic products labeled for disease control during transplant production in the greenhouse.

Sanitizing Greenhouse Surfaces and Treatment of Flats and Trays:

There are several different groups of sanitizers that are recommended for plant pathogen and algae control in transplant greenhouses. Alcohol is often used to disinfect grafting tools. All these products have different properties:

  • Quaternary ammonium chloride salts (Q-salts such as Green-Shield®, Physan 20®, KleenGrow™) are labeled for control of fungal, bacterial and viral plant pathogens, and algae. They can be applied to floors, walls, benches, tools, pots and flats as sanitizers.
  • Hydrogen Dioxide, Hydrogen Peroxide, and Peroxyacetic Acid containing products (ZeroTol® 2.0, OxiDate® 2.0, SaniDate®12.0) kill bacteria, fungi, algae and their spores on contact. They are labeled as disinfectants for use on greenhouse surfaces, equipment, benches, pots, trays and tools.
  • Chlorine bleach may be used for pots or flats, but is not recommended for application to walls, benches or flooring. When used properly, chlorine is an effective disinfectant. A solution of chlorine bleach and water is short-lived and the half-life (time required for 50 percent reduction in strength) of a chlorine solution may be as little as a few hours.

New flats and plug trays are recommended for the production of transplants to avoid pathogens that cause damping-off and other diseases. If flats and trays are reused, they should be thoroughly cleaned and disinfested as described below. Permit flats to dry completely prior to use. Styrofoam planting trays can become porous over time and should be discarded when they no longer can be effectively sanitized.

  • Sanitizing trays with Chlorine: Dip flats or trays in a labeled chlorine sanitizer at recommended rates (3.5 fl oz. of a 5.25% sodium hypochlorite equivalent product per gal of water) several times. Cover treated flats and trays with a tarp to keep them moist for a minimum of 20 minutes. Wash flats and trays with clean water or a Q-salts solution to eliminate the chlorine. It is important that the bleach solution remains in the pH 6.5-7.5 range and that a new solution is made up every 2 h or whenever it becomes contaminated (the solution should be checked for free chlorine levels at least every hour using test strips). Organic matter will deactivate the active chlorine ingredients quickly.

For more information on seed treatments and disinfectant products labeled for use in the greenhouse please see the upcoming 2020/2021 Mid-Atlantic Commercial Vegetable Production Recommendations Guide.

Selected Organic and Conventional Fungicides, Bactericides

An updated table for selected organic and conventional fungicides and bactericides labeled for greenhouse use will be available in Table E-11 in the upcoming 2020/2021 Mid-Atlantic Commercial Vegetable Production Recommendations Guide. The table includes an updated comprehensive list of conventional and organic fungicides and biopesticides approved for greenhouse use.

Gramoxone/paraquat Mandatory Training Required Before Use

Spraying for pests

All pesticide certified applicators must successfully complete an EPA-approved training program before mixing, loading, and/or applying paraquat.

Anyone using Gramoxone, Firestorm, Helmquat, Parazone, and other paraquat products must complete an EPA-mandated training before application.

After November 14, 2019, the EPA requires companies to have newly labeled products on the market.

 

The following are items related to the new label for paraquat products:

  • Only certified applicators, who successfully completed the paraquat-specific training, can mix, load or apply paraquat.
  • No longer allow application “under the direct supervision” of a certified applicator.
  • Restricting the use of all paraquat products to certified applicators only.
  • EPA required Online Training – users must create an account with username and password.
  • A certificate will be delivered by the end of the training after successful completion of the online exam.
  • Applicators must repeat training every three years.

For additional information and FAQs about the paraquat training go to the EPA Paraquat Training website

Vegetable IPM Update 10/02/19

Note:  This is the last regular edition of the Vegetable IPM Update for the season.  We will provide additional updates on specific pest/disease issues as they arise.

Sweet Corn

Corn earworm (CEW) moth catches remain at moderate levels.  Overall, CEW numbers represent a normal early fall population.  Moth counts will decline with cool night temperatures (especially those forecast for the upcoming weekend), but look for rebounds when nighttime temperatures exceed 60F.   Economically damaging populations of this pest are present throughout the state, and all remaining silk stage plantings are at risk of crop injury if strict spray schedules are not observed.

 

[Read more…]

Vegetable IPM Update 9/25/2019

Joe Ingerson-Mahar and Kris Holmstrom

This is an abbreviated edition of the IPM Update.  The final IPM Update for the 2019 season will appear next week.  Pest alerts will appear as needed.

 

Sweet Corn

European corn borer (ECB) remains at very low levels across most of the state, with a few moths (1 per night) being found in the Hillsborough and Milltown areas this past week.  Late-season plantings are still at risk from ECB feeding but are likely to be minimal at this point.  In the late-season corn borers tend to lay eggs on many different crops, including apples and eggplant, so do not be surprised that you find ECB on unexpected crops.

Corn earworm (CEW) numbers have fallen somewhat across the state with the generally cooler night-time temperatures of the past week.  Counts in both blacklights and pheromone traps are highly variable across the state.

Blacklights – counts statewide range from 0 to 5 moths per night with larger numbers in the southern half of the state.  Spray schedules range from 4 to 5-day to 3-day.

Pheromone traps – counts have also declined somewhat, due both to cooler weather and aging sweet corn.  Plantings that are tasseling now will be the most attractive to CEW moths and these plantings should be on 3-day schedules, especially in South Jersey where despite declining numbers there is still a large reservoir of moths in the area.  Highest counts seen are at Eldora with 58 moths per night and Beckett with 48 moths per night.  The pheromone traps are showing a 4-day or 3-day schedule.

Fall armyworm pressure has been light in at least the southern part of the state.  Infestations of less than 10% are the norm.

Peppers

Corn earworm numbers have been high in pheromone traps placed at pepper fields.  Some injury has been found from these pests where insecticide applications have been backed off.

Beet armyworm continues to be a significant pest in the southernmost part of the state with counts at 73 per night at Jones Island and 32 per night at Pedricktown.  Traps in Hammonton record less than 10 per night.  Plant injury has occurred at counts under 5 per night.

Pepper weevil has become a widespread pest with now at least 8 farms infested in the Swedesboro, Glassboro, Hammonton and East V

Adult weevil on pepper

ineland areas.  It is hard to estimate yield loss to weevils but most of these farms probably have light to moderate loss.  Two of the farms had severe losses from weevils this year.  Farms that are located near, or do business with, processors should routinely have yellow pheromone traps placed in high traffic areas on the farm and in fields.  Weevils are most likely to be transported to the farm by hitchhiking on vehicles or on produce bins, though they are capable of spreading on their own to adjacent fields of solanaceous crops.

Other insect pests

Brown marmorated stinkbug has nearly become absent in blacklight trap catches.  At this time of year, they are seeking ov

Hawaiian beet webworm on spinach

erwintering sites and do not present much of a problem for vegetable crops.  Centerton had the highest nightly count of 2 for the past week.

Hawaiian beet webworm (HBWW) moths have been trapped in blacklights in South Jersey – Jones Island and Eldora.  Though the numbers are light, farmers with spinach, beets, and chard should check their fields for the presence of webbing and feeding injury.  These are small migratory moths usually occurring in mid-to-late summer.  Their favored host is the pigweed, Amaranthus sp., but they are capable of causing defoliation and contamination to crops.  Since they are migratory and have a short life cycle they can rapidly appear and cause extensive damage to crops unnoticed.  There were isolated highly-infested weedy areas last year on vegetable farms in South Jersey.

Twilight Meeting 10/10: Cleaning and Sanitizing Grading Equipment

Join us at the Rutgers Snyder Research Farm to discuss the cleaning and sanitizing of produce grading equipment.

October 10, 2019  from 4:00 p.m. to 7:00 p.m.

This event is free but please register through Eventbrite or call Brandi at 856-451-2800

Cleaning and Sanitizing Grading Equipment

Allium leaf miner update: 09/20/19

Allium Leaf Miner

Allium leaf miner (ALM) feeding/egglaying scars were detected in chives and scallions near Princeton (Mercer Co.), NJ on Friday of this week.  This indicates that the second (fall) flight of these flies is now underway, and damage is occurring.

Allium leafminer oviposition scars on onion

Photo: Sabrina Tirpak. Allium leafminer oviposition scars on onion

Growers should consider initiating the control method of their choice at this time.  Affected crops include chives, scallions, garlic, onions and leeks.

Floating row covers, kept on until the second flight ends will help minimize access to plants.  Insecticide applications targeting adults may be helpful as well, although frequency of applications is uncertain.  Spinosyn materials (Radiant, Entrust (OMRI approved)), pyrethroids (Mustang Maxx, Warrior), and pyrethrin materials (Pyganic (OMRI approved)), neonicotinoids (Scorpion, Venom) and the insect growth regulator Trigard are labeled for miner control.

Adult activity and observations of feeding will be reported on in the IPM Update as they occur.  At this time, all growers should respond to the second adult generation.  We will attempt to identify the end of the second flight so that growers know when the risk of infestation has abated.