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…]
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.
Organic Production: Suppressing Soil-borne Pathogens
Organic Options:
Cabbage Maggot & Pest Control Efficacy
A round table meeting of the Organic Farm Advisory group took place this week with discussion on the successes and problems of last season. The need for relative efficacy continues and brings up the chance to revisit a timely article that was the result of last year’s discussion.
What are my organic treatment options and how well do they work? As an organic grower, I sometimes accept less control, and more costly treatment than conventional farmers, but the information on efficacy is unclear. If Rutgers isn’t doing efficacy trials, can you sift through the literature to tell me what others have found that definitely works?
Control of cabbage root maggot (CRM) is a timely example that illustrates the ‘struggle for relative efficacy’ in making organic recommendations when compared with conventional options. Forsythia in bloom–any day now–occurs at about the same time that farmers can expect CRM to damage their transplanted cole crops. Even light CRM infestations can kill small seedlings and transplants, delay crop development, and render root crops unsaleable. Higher populations can kill older plants or reduce yield.
- monitoring and control of CRM in cole crops.
- the use of online weather station degree-day (DD) data to predict CRM activity and timing of treatment – instead of relying on phenology.
- how the lack of field research capacity makes recommendations difficult for organic pest controls in comparison with conventional controls.
- why talent scouting (sifting through the literature) is an adjunct to research capacity, not a replacement.
Intro to Organic Vegetable Production Field Day from Penn State, Aug 6, 2015
Location
Good Work Farm
4791 Rock Road
Zionsville, PA 18092Date: August 6, 2015 from 4 to 7 pm
4:00 PM Farm Tour
4:45 PM Scouting and Identification Exercise
5:45 PM Disease Management and Discussion
6:30 PM DinnerRegistration
This field day is part of the Introduction to Organic Vegetable Production series. No pre-registration is required. Walk-in to join us. $10 walk-in fee covers dinner and materials.
Penn State Extension is offering An Introduction to Organic Vegetable Production Field Day focusing on plant disease scouting, identification, and management on the evening of August 6th at Good Work Farm in Zionsville, PA located about an hour north of Philadelphia. For more information see Organic Vegetable Production Field Day.
Leaf Mold in Tomato
Leaf mold (formerly Fulvia fulva) has been confirmed in field-grown tomatoes in Cape May County.
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. 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.](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2015/07/Leaf-mold3-500.jpg)
Symptoms of leaf mold on infected tomato plant. Note bright yellow leaves and olive-green spores developing on undersides of leaves.
Anthracnose and Alternaria Leaf Blight in Cucurbit Crops
Anthracnose and Alternaria leaf blights are showing up in cucurbit crops. Weather conditions in the region continue to be ideal for disease development across all vegetable crops. The regular rainfall and high humidity that have plagued the region only acts to exacerbate problems. All cucurbit growers should be on high alert for foliar diseases such as anthracnose and Alternaria as well as downy mildew. Anthracnose and Alternaria produce distinct circular spots on infected leaves, and in most cases, symptoms begin on the older leaves.
With Alternaria, diagnostic concentric black rings will be develop within the spots. With Anthracnose, black setae (hair-like projections) will develop on the veins of infected tissue on the underside of leaves.
Anthracnose and Alternaria are easily controlled with weekly protectant fungicides such as chlorothalonil and mancozeb as long as they are applied prior to the arrival of the pathogen. Control of downy mildew will require downy mildew specific fungicides. As long as these weather conditions persist all growers need to remain on strict weekly protectant fungicide programs and be scouting on a daily basis. Organic growers can apply copper and other labeled products to help suppress development of these diseases.
Complete foliar coverage is critically important for the control these diseases.
For more information on the control of anthracnose and Alternaria leaf blight in cucurbit crops please see the 2015 Commercial Vegetable Production Guide.
Phytophthora Control During Wet Weather
Most of New Jersey has been plagued by heavy rains and pop-up thunderstorms these past few weeks making conditions ideal for pathogens such as Phytophthora blight (P. capsici) on pepper, eggplant, tomato, and cucurbit crops. Unfortunately, Phytophthora blight can be found on most farms in the southern part of the state. Poor crop rotations with susceptible hosts only make matters worse. The pathogen has an increasing host range that also includes snap and lima beans, and all crops, other than a few resistant bell pepper cultivars, lack any resistance to the pathogen. [Read more…]