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

March 28, 2020

Seed Corn Maggots in the Fields Early this Spring

Even though most people are focused on the pandemic, life on the farm still goes on. That also means, plant pests and crop production will be business as usual during the growing season. With the mild winter and earlier than usual warm springtime temperatures, many insect pests we often see in spring are emerging earlier than usual. One that has already been detected in Southern New Jersey is the seed corn maggot. This pest is about 2-3 weeks ahead of schedule in our region.

Seed Corn Maggots

Eggs, larvae, pupae and adult flies of the Seed Corn Maggot, photo credit Cornell University

Seed corn maggot adult flies have been seen in Gloucester County this past week. As vegetable farmers begin planting crops affected by seed corn maggot (snap beans, lima beans, corn, turnips, peas, cabbage, and cucurbits – mainly squash and cucumber), it is important to use insecticidal seed treatments to protect these crops. Adult flies are most likely in other areas of New Jersey right now. Cool to moderate temperatures and wet weather increase activity and survivability of this early season pest. When adult maggots lay eggs near the planting hole, eggs can hatch in just a few days after being laid. Maggots then can burrow into seeds or seedlings, feed for a period of 2 to 3 weeks and then develop into egg-laying adults. There can be many generations per year, but activity is heightened during periods of cool and wet weather.

Adult flies are most abundant in fields with cover crops, soils with high organic matter, fields where leaves have been applied, fields that have just been tilled, or in fields that have had manure applied. When a seed or seedling is attacked, it may continue to grow, but will be weak and not produce a crop. Preventative control methods are most effective, since once larvae are found causing damage in the field, they are difficult to control underground. Some commercial insecticide seed treatments are available and to find products for individual crops see the 2020-2021 Mid-Atlantic Commercial Vegetable Production Recommendations guide. This information can be downloaded free at https://njaes.rutgers.edu/pubs/publication.php?pid=E001 .

Other preventative methods include row covers to create a barrier between the insect pest and the seeds or seedlings, waiting to plant in fields until soils and air temperatures are warm enough to quicken germination and plant growth, and selecting fields for early plantings with low organic matter and that do not remain wet for long periods.

Later in the season, even though this pest may be present, most crops can germinate and grow fast enough to overcome low numbers of larvae present in the field. When warmer temperatures and drier conditions occur seed corn maggot populations generally decrease.

Filed Under: Organic Production, Vegetable Crops
March 24, 2020

Allium leaf miner update: 03/24/20

Allium Leaf Miner

Allium leaf miner (ALM) feeding/egglaying scars were detected in chives near Princeton (Mercer Co.), NJ on Tuesday of this week.  This indicates that the first (spring) flight of these flies has now begun and damage will increase.  Additionally, extension personnel at Penn State have reported finding the first feeding scars in several southeastern PA sites within the past few days.  It is believed that all of these occurrences are very recent.

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 this 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),  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 first adult generation.  We will attempt to identify the end of the first flight so that growers know when the risk of infestation has abated.

 

 

 

Filed Under: Organic Production, Vegetable Crops Tagged With: , ,
March 17, 2020

Status of U.S. Consular Operations in Mexico in Light of COVID-19

In response to the global pandemic COVID-19, and in line with the Mexican government’s call to increase social distancing, the U.S. Embassy in Mexico City and all U.S. consulates in Mexico will suspend routine immigrant and nonimmigrant visa services starting March 18, 2020, and until further notice. For farmers this means, H-2A workers and others from Mexico may be prevented from entering the U.S. until further notice. NJ Farm Bureau is researching the subject for more clarification. For now to see more information go to the U.S. Embassy’s website at: Field of plantershttps://mx.usembassy.gov/status-of-u-s-consular-operations-in-mexico-in-light-of-covid-19/

Filed Under: Blueberry, Commercial Ag Updates, Cranberry, Fruit, Landscape, Nursery, & Turf, Nursery, Organic Production, Strawberry, Tree Fruit, Turf, Uncategorized, Vegetable Crops, Wine Grape
February 14, 2020

Phytophthora-tolerant and -resistant bell pepper variety trial reports

Phytophthora blight caused by Phytophthora capsici is one of the most economically important diseases in pepper, tomato, and cucurbit production in New Jersey. Each year for the past few decades Rutgers has evaluated new bell pepper cultivars and breeding lines for their resistance to P. capsici in field trials at the Rutgers Agricultural Research and Extension Center (RAREC) near Bridgeton, New Jersey, and in some years at research trials on farms near Vineland, NJ. The pathogen, an oomycete – ‘water mold’ is favored by warm weather and wet soils during the production season and can survive between seasons in the soil as oospores. Once found in a field, the pathogen can establish itself, and be very difficult to control even with the use of fungicides. Fortunately, in bell pepper, phytophthora blight resistant/tolerant cultivars have been commercially-available for over 20 years now and have been used extensively by bell pepper growers throughout the state. Each year, as mentioned above, Rutgers evaluates these bell peppers for their resistance to P. capsici in heavily-infested fields as well as evaluate each for their fruit quality characteristics (e.g., color, wall thickness, number of lobes, and development of ‘silvering’). Some important points to remember. The pathogen is consistently evolving because of its sexual activity (i.e., mating types and oospore production). The more researchers look into the pathogen’s genetic diversity, the more they seem to find. The pathogen can develop resistance to important fungicides. Insensitivity to mefenoxam and copper resistance have been know for a very long time. Finally, phytophthora resistant cultivars such as Paladin which have been used extensively in southern New Jersey for the past 20 years appear to be breaking down. Over the past few years a number of new phytophthora resistant/tolerant bell peppers with new sources of genetic resistance have been released and evaluated by Rutgers. Some of these new bell peppers also have varying levels of resistance to bacterial leaf spot, with one – ‘Playmaker’ having X10R resistance to bacterial leaf spot and tolerance to P. capsici. Because of the increased reports of bacterial leaf spot and copper resistance in recent years and the difficulty in controlling it alone, all bell peppers grown in NJ at some point will need to have to have X10R resistance and phytophthora blight resistance. Importantly, for organic bell pepper growers, if you have not already done so, you should be evaluating these new lines to see if they meet your needs. The easiest way to mitigate both diseases are to start with genetic resistance. Below are the bell pepper variety reports going back to 2005 for review.

For more information on recommended bell pepper cultivars please visit the Pepper Section in the 2020/2021 Mid-Atlantic Commercial Vegetable Productions Recommendations Guide.

Pepper Tolerance 2005

Pepper Tolerance 2006

Pepper Tolerance 2007

Pepper Tolerance 2008

Pepper Tolerance 2009

Pepper Tolerance 2010

Pepper Tolerance 2011

Pepper Tolerance 2012

Pepper Tolerance 2013

Pepper Tolerance 2014

Pepper Tolerance 2015

Pepper Tolerance 2016

By: Andy Wyenandt and Wesley Kline

 

Filed Under: Commercial Ag Updates, Organic Production, Vegetable Crops Tagged With: , ,
February 1, 2020

Options for controlling basil downy mildew in the field

For over a decade, basil downy mildew (BDM) has caused significant losses in basil grown in organic and conventional field and greenhouse production across the United States. At the time of its introduction, there were very few fungicides labeled for its control making it nearly impossible to grow a successful crop in many areas of the country. The pathogen, Peronospora belbahrii, is an obligate parasite, meaning it needs a living host in order to survive. Thus, in more northern regions of the country that experience a freeze (i.e., winter), the pathogen will die when the host freezes during the fall. Because of this, the pathogen must be re-introduced the following spring or summer from southern regions of the country. This is similar to cucurbit downy mildew, where the pathogen can survive on the host that is growing in the field during the winter months (e.g., southern Florida or Mexico). The exact timing of when basil downy mildew may show up in your geographic region depends on a number of factors. The more southern you are located in the continental US, the more likely the pathogen will show up earlier in the spring or summer. In New Jersey the pathogen has been reported as early as 12 June and as late as 2 August. The first step in mitigating losses to basil downy mildew is in your selection of the best varieties. In recent years, there have been a number of new commercial sweet basil varieties released with a high level of resistance to basil downy mildew. Sweet basil varieties without BDM resistance should always be grown prior to the expected arrival of the pathogen in your region. There is a BDM monitoring website, led by Cornell University, which tracks the movement of the pathogen across the country each year. Growers can use the website to see where BDM has been reported across the country. Once BDM has been detected in your area you can expect it to remain active until the end of the production season. BDM resistant sweet basil varieties should always be grown after BDM has been detected in your region to help mitigate losses due to the disease. If you are located in the southern US, the easiest approach would be to use BDM resistant sweet basils the entire production season. All basil growers must remember that any of the new BDM resistant sweet basils are not “immune” to the disease. If disease pressure becomes extremely high or environmental conditions become highly conducive for disease development over a long period of time BDM resistance will break down for that season. Thus, it is extremely important to still initiate a fungicide program when using any DMR resistant sweet basil, especially if disease pressure is expected to be high.

For several years, the IR-4 Project has been working diligently with stakeholders and registrants to facilitate the registrations for a number of fungicide products (conventional, biopesticide, and organic) to control basil downy mildew. These efficacy studies have been done by Extension personnel at many Universities across the country. The following is a comprehensive list of conventional, organic, and biopesticides currently labeled for the control of BDM in the US.

Conventional fungicides currently labeled for basil downy mildew control:

  • Ranman 400 SC, FMC Agricultural Products
    • cyazofamid, FRAC Group 21
    • Can be used in a greenhouse, 0-day PHI
  • Revus, Syngenta Crop Protection,
    • mandipropamid, FRAC Group 40
    • Micora labeled for use in the greenhouse; 1-day PHI
  • Ridomil Gold, Syngenta Crop Protection
    • mefenoxam, FRAC Group 4
    • Field use only; 21-day PHI
  • Orondis Ultra, Syngenta Crop Protection (not yet approved by EPA)
    • oxathiapiprolin (FRAC Group 49) + mandipropamid (FRAC Group 40)
    • Field use only (foliar); 0-day PHI
  • Segovis, Syngenta Crop Protection
    • oxathiapiprolin, FRAC Group 49
    • Greenhouse use only; transplants for retail sale
  • Presidio, Valent USA
    • fluopicolide, FRAC Group 43
    • Field use only; 1-day PHI;
    • Adorn labeled for use in the greenhouse
  • Reason 500SC, Gowan Company and Bayer CropScience LP
    • fenamidone, FRAC Group 11
    • Field and greenhouse use; 2-day PHI

Organic Materials Review Institute (OMRI Listed) federally registered fungicide products for basil downy mildew control include:

  • Actinovate AG (Streptomyces lydicus, Novozymes BioAg Inc.)
  • Double Nickel 55 and LC (Bacillus amyloliquefaciens strain D747 Certis U.S.A.)
  • Aviv (Bacillus subtilis strain IAB/BS03, STK Bio-Ag Technologies)
  • Regalia (extract of Reynoutria sachalinensis, Marrone Bio Innovations)
  • Trilogy (neem oil, Certis U.S.A.)
  • Milstop, Carb-O-Nator (potassium bicarbonate, BioWorks Inc., Certis USA LLC)
  • Oxidate (hydrogen dioxide, BioSafe Systems LLC)
  • Oxidate 2.0 (hydrogen dioxide; peroxyacetic acid, BioSafe Systems LLC).
  • Cueva Fungicide Concentrate (copper octanoate, Certis USA, LLC)
  • Romeo (cell walls of Saccharomyces cerevisiae strain LAS117, Lesaffre Yeast Corporation)

Biopesticide products federally registered for basil downy mildew control that are not OMRI listed include:

  • mono- and di-potassium salts of phosphorous acid (K-Phite, Plant Food Systems)
  • phosphorous acid, mono- and dipotassium salts (Confine Extra, Winfield Solutions LLC)
  • phosphorous acid, mono- and dibasic sodium, potassium, and ammonium salts (Alude and Phostrol, Nufarm Agricultural Products)
  • potassium phosphite (Fosphite, JH Biotech, Inc.; Fungi-Phite, Plant Protectants, LLC; Prophyt, Helena Chemical Company; Rampart, Loveland Products, Inc.)
  • potassium bicarbonate (Armicarb 100, Helena Chemical Company)
  • a combination of potassium phosphate and potassium phosphite (Phorcephite, Loveland Products, Inc.)
  • sodium tetraborohydrate decahydrate (Prev-Am Ultra ORO Agri, Inc.)
  • hydrogen peroxide, peroxyacetic acid (Rendition, Certis USA LLC)
  • hydrogen peroxide; phosphorous acid; mono- and dipotassium salts (Oxiphos, BioSafe Systems LLC)
  • citric acid (Procidic, Greenspire Global Inc.)
  • hydrogen peroxide; peroxyacetic acid (Sanidate 12.0, BioSafe Systems, LLC)
  • Sodium tetraborohydrate decahydrate (Prev-Am Ultra, ORO Agri, Inc.)
  • Laminarin (Vacciplant, UPL NA Inc.)

Some important points to consider:

  1. Some of the conventional fungicides listed above are sold under different product names, depending on whether the product can be used in the field or greenhouse or for greenhouse transplant use. Other products have both a field and greenhouse use on the same product label.
  2. Although a product is listed as a biopesticide, it does not mean it has an OMRI-approved label. All growers should follow labels accordingly. Remember, the label is the law.

Proper control of BDM depends on a number of factors including the environment, disease pressure, and the timing of fungicide applications. Prolonged periods of wet weather and high relative humidity during the production season will make BDM control more difficult regardless of the products used to control it. The amount of disease pressure present in your field will also have an impact on your ability to control BDM. This is especially important in organic production systems where organic products often have better chance of working if disease pressure remains low. This is why growing a basil downy mildew resistant sweet basil is so important; as many organic products as reported by growers have not shown to be as effective as needed.

Research has shown that fungicide applications (e.g., conventional, bio-, or organic) initiated after the start of disease development most often leads to poor control and crop loss. Therefore, it is important to anticipate the arrival of BDM and initiate a fungicide program prior to the onset of disease development. This is also why monitoring the progress of the pathogen in the US is so important. In some areas, the disease might arrive on infected basil transplants from southern states. If this happens, the basil downy mildew will be in present long before the anticipated arrival of the pathogen due to weather patterns.

How products work against basil downy mildew

Conventional fungicides often work by inhibiting spore germination or spore production. Thus, the importance of having them applied prior to the arrival of the pathogen. Some of these products, such as mefenoxam or oxathiapiprolin, move within the plant, giving them an advantage when applied as drip applications. Biopesticides, such as the phosphites, are truly systemic and move up and down within the plants vascular system; however, research has shown that phosphites are more effective as foliar applications than when applied as drip applications. Some biopesticides, such as Oxidate and hydrogen peroxide, act as disinfestants killing spores they come into direct contact with. Because BDM sporulates on the underside of the leaf, these products (and most other fungicides) must reach the undersides of leaves during application in order to be effective. The same holds true for copper products. Copper is a protectant fungicide inhibiting spore germination. Therefore, it must reach the undersides of leaves. Organic products, such as those containing Bacillus and Streptomyces, act as an antigonist against BDM on the leaf surface and must be remain present in high enough populations on the leaf surface to provide control. This is often difficult to do because it requires multiple applications per week with short retreatment intervals. Often, these products are ineffective due to unfavorable environmental conditions. For growers trying to reduce conventional fungicide use, these products as well as disinfectant products will also kill off any biological control agents, so beware.

For information on Rutgers DMR sweet basils, where to purchase seed, as well as control strategies, and ongoing research efforts please follow the Rutgers basil downy mildew breeding program on Instagram at #Rutgersbasil.

Additional Resources:

Tracking basil downy mildew in the US

Managing basil downy mildew

Fungicides for the control of BDM

Controlling basil downy mildew in the greenhouse

 

By: Andy Wyenandt, Kathryn Homa (IR-4 Project), and Jim Simon, Department of Plant Biology, NJAES, Rutgers University

Filed Under: Commercial Ag Updates, Organic Production, Vegetable Crops Tagged With:
January 22, 2020

Organic Transplant Production: Suppressing Soil-borne Pathogens

Pathogens such as Fusarium, Pythium, Phytophthora, Thielaviopsis and Rhizoctonia that cause pre- and post-emergent damping-off can cause serious problems in organic (and conventional) transplant production. The key to controlling and/or suppressing damping-off pathogens with biological controls is keeping the biological populations high and continually present on root surfaces of the host, and by following good cultural practices. [Read more…]

Filed Under: Commercial Ag Updates, Organic Production, Vegetable Crops Tagged With: , ,