Allium leaf miner oviposition scars- garlic.

Leaf mine on onion

Allium leafminer oviposition scars on onion

Two probable infestations of allium leafminer have been discovered.  One of these was on the Hunterdon/Warren County border involving overwintered garlic and onions planted this spring.  The second, a very minor infestation, was found near Princeton in Mercer County on overwintered chives.  While we await word from USDA as to where specimens should be sent for final confirmation, the signs of infestation are very characteristic of allium leafminer, and larvae and eggs were found in association with the egg laying scars (oviposition scars) on the leaves of onions and garlic.  Both of these infestations appear to be very recent, with larvae in very early growth stages. [Read more…]

• Rhizoctonia root rot has been found on newly emerged cucurbit seedlings. The cool, cloudy weather has significantly slowed emergence and transplant growth the past few weeks. The longer it takes for emergence and transplants to establish themselves, the more likely they are to pick up pre- and post-emergent damping-off diseases such as Rhizoctonia or Pythium.
• Botrytis is being reported in greenhouse tomatoes and in strawberries fields. The weather the past few weeks has been ideal for its development in a multitude of crops. Growers need to scout on a regular basis and incorporate Botrytis specific fungicides into their weekly maintenance sprays as long as the current weather pattern remains the same.
• Transplant health – transplants that have yet to be put in the field and that are showing signs of stress via the lack of fertility and water to keep them to size can become predisposed to a multiple of opportunistic fungal and bacterial pathogens. Growers need to pay close attention to and adjust fertility and watering programs on a daily basis and consider preventative fungicide applications.

Mites and feeding signs on lower leaf surface. Aphids also present.

Two-spotted spider mite (TSSM) infestations have recently been discovered in high tunnels.

TSSM feeding results in small white pin-spots on the upper leaf surface (see photos).  Mites are actually underneath leaves.  These pests can increase dramatically in the warm, dry environment of the tunnel.

Check 5 plants each in 5 separate locations in the tunnel.  Inspect the entire plant, and be sure to check the underside of leaves that display the whitish mite feeding.  If mites are found, it is best to immediately treat.  TSSM is much more easily managed, when the problem is addressed at low levels.  If allowed to spread throughout the tunnel, TSSM will be much more difficult to control.

See the 2016 Commercial Vegetable Production Recommendations – Pest Management section for materials that are labeled for use in greenhouse structures, including those that are OMRI approved.
[Read more…]

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…]