Andy Wyenandt

This is an archive of Dr. Wyenandt's posts on the Plant and Pest Advisory.

May 4, 2016

Orondis, a new Fungicide from Syngenta

Syngenta Crop Protection released Orondis, a new fungicide with a new mode-of-action for use in vegetable production this past winter. Because of its winter registration, Orondis was not included the 2016 Mid-Atlantic Commercial Vegetable Production Guide.

Orondis (oxathiapiproplin, U15) targets the oxysterol binding protein that is a part of the fungal cell wall. The active ingredient inhibits growth of the fungus as well as sporangia production and zoospore germination. Orondis has a low solubility (i.e., locally systemic), is translaminar; and will protect new growth.

Orondis is currently sold as a co-pack with either mefenoxam (Orondis Gold), chlorothalonil (Orondis Opti), or mandipropamid (Orondis Ultra). Growers will be required to tank mix Orondis with its partner during 2016 season. In 2017, the partners will be formulated together. Importantly, Orondis will not receive an individual label in the US.

Orondis has different use rates and restricted seasonal use. The labels need to be followed carefully and accordingly to help manage fungicide resistance development. Simply, if Orondis is applied via drip system, it cannot be used as a foliar spray (and visa-versa). If Orondis is applied as a foliar application it cannot be used via the drip. Thus, growers planning on using Orondis need to plan ahead of time and accordingly! The rates for Orondis and it counterpart will differ by crop, pathogen, and desired use (drip vs. foliar). [Read more…]

Filed Under: Vegetable Crops
May 4, 2016

New Downy Mildew Grant Award will Aid Growers

For the past 6 years, Rutgers has led efforts in the breeding of sweet basil for resistance to downy mildew. Currently, basil downy mildew threatens 100% of the basil acreage in the US and other parts of the world.

Rutgers University, along with researchers at Michigan State, University of Florida, Oregon State University, Cornell University, California State University, and North Carolina State University as well as the USDA Agricultural Research Service have been awarded a $2.3-million USDA grant to help fight downy mildew in a number of highly valuable crops. The announcement from MSU who leads this effort can be found on MSU Today. 

Filed Under: Vegetable Crops Tagged With: ,
May 4, 2016

Got humidity? Get rid of it!

Unfortunately, closed greenhouses retain heat and humidity which can spell problems if left unchecked.

Remember, high relative humidity equals wet leaves which favor the development of fungal diseases such as Botrytis or bacterial diseases such as bacterial leaf spot. To avoid potential problems, do your best to vent out as much humidity as possible in the late afternoon and/or early morning. Turn on circular fans to promote air movement and finish watering earlier enough in the day so leaves have enough time to dry out before nightfall.

As a side note, stressed transplants where water and/or fertility have been withheld are also more prone to disease development. A light fertilizer application may go a long way in improving transplant health before setting in the field.

Please see Table E-14 and pages E52-E54 of the 2016-2017 Commercial Vegetable Recommendations Guide for a list of control options.

Filed Under: Vegetable Crops
May 4, 2016

Wet Weather Ripe for Strawberry Fruit Rots

Anthracnose fruit rot of strawberry

Anthracnose Fruit Rot of Strawberry

Fruit rots in strawberry can cause significant losses if not recognized early and controlled. The use of good cultural practices such as: keeping fields weed-free and promoting good drainage; long crop rotations, and preventative fungicide applications are critical.

Pathogens such as anthracnose, gray mold (Botrytis), and leather rot can become systemic problems in strawberry plantings once established. All three fungal diseases are soil-borne and once in fields can be difficult to manage over the lifetime of the planting.

For growers new to strawberry production and/or those just looking for valuable resource(s), please visit Cornell University’s strawberry production website here. An Organic Strawberry Production Guide is also available.

The use of mulch (matted rows) to prevent/reduce soil splashing and keeping fruit from coming into direct contact with the soil surface can be beneficial in organic production systems where conventional fungicides cannot be used. Use of long crop rotations and staying away from areas of the farm with known instances of any of these pathogens is also important. Remember that same species of Colletotrichum that causes fruit rot in pepper and other crops can also infect strawberry.

[Read more…]

Filed Under: Organic Production, Vegetable Crops Tagged With:
May 1, 2016

Vegetable Disease Briefs – 5/1/16

  • Dickeya sp., an aggressive form of Black leg, has been confirmed on potato in New Jersey in 2016. Symptoms of Dickeya infection look similar to Black leg infection and can cause significant rot above ground (stems and foliage) and below ground (tubers). All potato growers should scout on a regular basis and report any suspect plants or fields.
  • There have been no new reports of cucurbit downy mildew.
  • With the cool, prolonged wet weather, basil downy mildew may become active in greenhouses or high tunnels that have been closed up to retain heat. Appropriate venting to keep relative humidity low and leaf wetness to a minimum is critically important to keep the pathogen from sporulating and spreading rapidly.
Filed Under: Vegetable Crops
May 1, 2016

Vegetable Disease Update – 5/1/16

Cabbage

Damping-off – To help control losses due to damping-off pathogens apply Ridomil Gold (mefenoxam, FRAC code 4) at 1 to 2 pt/A, MetaStar (metalaxyl, 4) see label, or azoxystrobin at 0.40 to 0.80 fl oz 2.08SC/1000 row ft (for Rhizoctonia only), or Ridomil Gold at 1.0 to 2.0 pt/A 4SL plus azoxystrobin at 0.40 to 0.80 fl oz 2.08SC/1000 row ft. in a band up to 7 in. after seeding. To help control damping-off pathogens in Collards and Kale only: Apply Uniform (mefenoxam +  azoxystrobin, 4 + 11) at 0.34 fl oz 3.66SE/1000 ft row. For more information please see 2016 New Jersey Commercial Vegetable Production Recommendations Guide.

[Read more…]

Filed Under: Vegetable Crops