Vegetable Crops Edition

Seasonal updates and alerts on insects, diseases, and weeds impacting vegetable crops. New Jersey Commercial Vegetable Production Recommendations updates between annual publication issues are included.
 
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January 9, 2020

Copper resistance in bacterial leaf spot found in New Jersey during 2020 growing season

Copper resistance has been detected in bacterial leaf spot of tomato and pepper and in Pseudomonas chicorii, the causal agent of bacterial leaf spot in basil, in New Jersey. While not surprising, copper resistance has been known to develop for decades now; however, this is the first time it has been confirmed in vegetable crops in New Jersey. Copper applications for the control of bacterial diseases in many crops has been a mainstay for decades now and is often applied in weekly protectant fungicide programs. In 2019 and 2020, with help from Dr. Nrupali Patel and Dr. Don Kobayashi, bacteriologists in the Department of Plant Biology located on the New Brunswick campus, a survey was begun to determine which species of bacterial leaf spot are most prevalent in New Jersey vegetable crops. Bacterial leaf spot can be caused by four species of Xanthomonas: X. euvesicatoria, X. vesicatoria, X. perforans, and X. gardneri. Currently, there are four races of BLS found in tomato (T1-T4; one for each of the 4 species stated above) and eleven races found in pepper (0-10). Differential tests in southern New Jersey using various bell pepper lines over the past 15 years has suggested that the number of races of BLS in pepper has increased over time; with all races present in the State to date. Lab testing results from samples collected from the small number of NJ vegetable farms the last two summers has shown the presence of X. euvesicatoria in pepper, as well as X. euvesicatoria and X. perforans in both tomato and pepper in the state, with ~50% of all samples testing positive for copper resistance.

How do you know what species of bacteria are present on your farm?

The only way to determine which species of bacteria are present in tomato or pepper crops on your farm are to have them identified through laboratory methods.

How do you know what races of the pathogen are present on your farm?

That’s a difficult question to answer. Up to now, the only way to know is through differential testing. That means planting a number of different bell peppers with varying BLS resistance packages and monitoring which cultivars develop symptoms. For example, if you detect BLS development in Aristotle X3R (which has resistance to races 1,2, & 3); then you possible have races 4-10 present on your farm. If you were to plant Turnpike in that same field and you have BLS development in it, then you possibly have race 6 or 10 present, because Turnpike has resistance to BLS races 0-5 and 7,8,9. It’s extremely important to know what races of BLS are present so you can chose the proper cultivars to grow. Choosing the proper cultivar will do two things: significantly reduce the chances of BLS development and significantly reduce the number of copper applications on your bell pepper crop. As a note, there are a few non-bell peppers available with BLS resistance packages (see 2020/2021 Commercial Vegetable Production Recommendations Guide).

How do you know if copper resistance is present on your farm? 

Growers who have used copper applications for controlling bacterial leaf spot in crops such tomato or pepper for many years should always monitor for efficacy. If you notice or have noticed a loss in copper efficacy over time, then there is a good chance copper resistance is present. Once copper resistance is detected, further applications will be unwarranted and ineffective. The only method to truly determine if copper resistance is present is through laboratory testing, however growers who pay close attention to efficacy should have a good idea if copper is still effective.

What can you do to mitigate bacterial leaf spot development on your farm?

In crops such as bell pepper, it comes down to growing cultivars with resistance to BLS and knowing what races are present on your farm. Many of the recommend commercial cultivars have varying resistance packages to the different races of the pathogen. Some cultivars, such as Paladin which has Phytophthora resistance has no resistance to BLS. Other “older” cultivars such as Aristotle X3R has resistance to races 1-3; newer cultivars such as Turnpike has resistance to races 0-5,7-9; while cultivars such as Playmaker and 9325 have resistance to 0-10 (also known as X10R cultivars). Unfortunately, BLS resistance in commercial tomato varieties are lacking, but efforts from around the world are making progress.

Moving forward in 2021.

More sampling and surveying are planned for the 2021 production season in New Jersey. Growers who are interested having tomato or pepper samples collected from their farm for species determination and copper resistance testing are encouraged to contact their county agent so arrangements can be made.

 

 

 

Filed Under: Vegetable Crops Tagged With: ,
January 7, 2020

Understanding and Controlling Tomato Brown Rugose Fruit Virus

Tomato Brown Rugose Fruit Virus (ToBRFV) is an emerging virus in greenhouse tomato production worldwide. The virus was first identified in Israel a few years ago and has since been found in Europe, Asia, Mexico, and the US.  The pathogen is known to be present in greenhouse tomatoes in Mexico, and has occasionally been found in field tomatoes grown there (UMASS); it has also been found on imported fruit in FL (Also see VGN story below). An outbreak was reported (and contained) in CA in early 2019 but, unfortunately, the virus was found in greenhouse tomato production in New Jersey this past fall.

ToBRFV is more severe on young tomato plants and can result in 30-70% yield loss (UFL). Foliar symptoms of ToBRFV on tomato and pepper include deformed, crinkled leaves, mosaic, mottling, flecking, chlorosis, and/or necrosis (see images). Fruit symptoms include discoloration and rough brown patches or ringspots. Irregular fruit shape and maturation patterns may also occur. Browning of the veins in the fruit calyx in the early stages of fruit ripening may also be observed. Symptom expression can vary widely among tomato cultivars (UMASS); while some green fruit may be infected but remain asymptomatic until the fruit starts to ripen.

ToBRFV is a member of the tobamovirus family along with tobacco mosaic (TMV), tomato mosaic (ToMV), and tomato mottle mosaic (ToMMV). ToBRFV is especially worrisome for tomato growers because it has overcome the Tm-22 gene that confers resistance to tobamoviruses in many tomato cultivars. Like TMV, ToBRFV is very stable and easily transmitted by mechanical means; in a highly managed crop such as greenhouse tomatoes, this means that human activity is the primary vector. The virus may also be transmitted mechanically by bumble bees employed to pollinate greenhouse crops. The virus can be seedborne and research indicates that it is associated with the seed coat, not the embryo. This means that treatments such as hot water or steam should be effective in removing the virus from seed (UMASS).

Management practices for ToBRFV include planting of disease free seed and seedlings, scouting plants regularly for symptoms, and isolating symptomatic plants. Disinfect tools and workers’ hands frequently. Recent research has demonstrated that the most effective disinfectants include 10% bleach, 50% Lysol, and 20% nonfat dry milk (UMASS). Currently, no commercial tomato varieties are tolerant to ToBRFV. Peppers with tolerance to TMV and pepper mild mottle virus (PMMoV) have shown some tolerance (MSU). ToBRFV’s high stability allows it to stay infectious in the soil, in plant debris and on stakes for long periods—up to 20 years. There are reports of spread by bumble bee pollinators in greenhouse situations. However, there are no reports of plant-to-plant transmission by aphids, leafhoppers or white flies (MSU).

There are no sprays that can be applied that are effective in helping to reduce the virus’s spread. Seed and transplant production are the most critical steps since contamination at these steps may create a risk of further contamination (MSU). A number of County Offices have the equipment for doing the hot water seed treatment method. Please contact your county agent for more information. Importantly, as a note, there is very limited to no information on infested seed sources, with only a few greenhouse tomato cultivars with known problems.

Recommended actions include (from MSU):

  • Start with certified clean or treated seed from a reputable dealer. Do not purchase seed from unverified sources, especially if they come from known restricted areas.
  • Have greenhouse workers wash and sterilize hands and tools often.
  • Supply single-use gloves that are discarded between greenhouse ranges.
  • Provide protective clothing that stays in that greenhouse range or that is well washed before going to another range.
  • Dispose of symptomatic plants and plants within 5 feet of infected plants. Also, dispose of plants, strings, trays and media through incineration—DO NOT spread it out on your fields (or reuse it for other crops in the greenhouse)!
  • Monitor movement of equipment and workers between fields. Thoroughly wash equipment and possibly have workers bring a change of clothes.
  • Rogue and incinerate symptomatic plants and conduct any daily activity last in that greenhouse followed by good sanitation.

On November 15, 2019, USDA/APHIS issued an emergency federal order that calls for pre-export testing of tomato and pepper propagative material (plants, seeds, grafts, and cuttings) and fruit produced in any country where ToBRFV has been detected; to date, this list includes Israel, Jordan, Turkey, Greece, Italy, the United Kingdom, the Netherlands, China, and Mexico. Countries where ToBRFV has not been reported may state this fact by providing a letter from the nation’s plant protection organization: propagative material and fruit exported to the USA will then be exempt from the testing requirement. Tomato and pepper fruit from Canada will also be subject to inspection prior to export, because Canada imports these crops from Mexico and re-exports them to the US. US Customs and Border Protection will also increase inspections at U.S. ports of entry to ensure imported tomato and pepper fruit from Mexico, Israel, the Netherlands, and Canada are free from symptoms of ToBRFV. (UMASS, USDA)

The NJDA, in cooperation with USDA APHIS PPQ, has been assisting affected NJ tomato producers in identifying critical control points and implementing the best management practices necessary to reduce the threat of introducing Tomato Brown Rugose Fruit Virus (ToBRFV) into future production. Tomato growers in New Jersey who suspect ToBRFV are encouraged to contact their county agent and the NJDA Division of Plant Industry. The NJDA is working with USDA APHIS PPQ to establishing testing protocols and will facilitate the screening of suspect plants.

References:

Dr. Anglela Madeiras (UMass)

http://ag.umass.edu/greenhouse-floriculture/fact-sheets/tomato-brown-rugose-fruit-virus-tobrfv

Dr. Ron Goldy (Michigan State University)

https://www.canr.msu.edu/news/tobrfv-a-new-concern-for-tomato-and-pepper-producers

Kendall Stacy (University of Florida)

http://blogs.ifas.ufl.edu/pestalert/2019/07/23/tomato-brown-rugose-fruit-virus/

American Seed Trade Association

https://www.betterseed.org/wp-content/uploads/ToBRFV-QA.pdf

USDA/APHIS

https://www.aphis.usda.gov/aphis/newsroom/stakeholder-info/sa_by_date/2019/sa-11/tomato-brown-rugose-fruit-virus

Vegetable Grower News – Tomato Brown Rugose Virus Concerns Growers

Filed Under: Commercial Ag Updates, Vegetable Crops
November 7, 2019

6-Week Urban “Annie’s Project” Farm Management & Business Training Course

Especially aimed at NJ farm women and veterans, Rutgers Cooperative Extension (RCE) will present a new, urban-focused version of the popular Annie’s Project titled “Farming in New Jersey’s Cities and the Urban Fringe.” Classes will be held simultaneously in Roseland, New Brunswick and Cherry Hill on Dec. 3, 10, 17 and Jan. 7, 14, 21, between the hours 6 – 9 p.m. Registration is currently open and is $150 until Dec. 2. Dinner will be provided at 5pm each evening of the class. [Read more…]

Filed Under: Commercial Ag Updates, Fruit, Vegetable Crops
October 10, 2019

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

Filed Under: Blueberry, Commercial Ag Updates, Fruit, Landscape, Nursery, & Turf, Organic Production, Tree Fruit, Turf, Vegetable Crops, Wine Grape
October 2, 2019

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…]

Filed Under: Organic Production, Vegetable Crops
September 26, 2019

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.

Filed Under: Organic Production, Uncategorized, Vegetable Crops